I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

I have pretty much the same thing in my house. i think the motors are
20 years ould now.

Very unlikely to have that many defective motors. I'd look to another
problem in mounting or gearing. My first guess would be the motor is
too small for the pulley gearing you have, check a new one with an amp
meter and see if its pulling more than name plate. If so, change
pulleys or go to larger motor.

Also possilbe that mounting is poor taking the bearings out.

I suppose you'de know it you have low voltage problems at your site.
Even occasionally kills motors.

Karl

On 7/10/2013 1:14 PM, Bob S wrote:

I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. ...

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson
Model S63ZZJKW-7333
HP 1/2 RPM 1725/1140 SF 1.3
V 115 Hz 60 PH 1 Code L
A 7.2 SFA 9.5 AMB 40C
Made in Mexico
....

I'm agreeing w/ Karl; Emerson isn't just some generic import Chinese
no-name; generally while they're assembled in Mexico they're good stuff.

A couple of other thoughts -- it's "humid" environment--any chance it's
actually condensing environment and you're drowning them in internal
condensate? Or are they getting wet from watering system or outside?

On mounting, they're not designed for anything except horizontal so if
even slightly off that'll be very bad on bearings.

Are they open-flow or is there air blockage via a damper system or
discharge/intake louvers or the like? That could drastically raise the
flow restriction and raise motor loading if designed/sized solely for
open unrestricted flow...

What does the vendor say? Surely they can't be happy replacing them
this frequently if is under warranty?

--

Do these motors still rotate freely when disconnected, without fan blades?
If they're getting noisy, the sleeve bearings may be failing faster than if
these motors were used in less severe indoor indoors.
I've seen considerable damage from sleeve bearing failures where the rotors
drag on the stator poles.

Enclosed motors would very likely last much longer.

TEFC totally enclosed motors are available, and typically have ball
bearings, so they wouldn't be affected by shaft rust from humidity, or dust
wicking the oil out of the bearings.

--
WB
..........


"Bob S" wrote in message
...

I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

In article , dpb wrote:

Are they open-flow or is there air blockage via a damper system or
discharge/intake louvers or the like? That could drastically raise the
flow restriction and raise motor loading if designed/sized solely for
open unrestricted flow...

Careful with the assumption here - many fans draw _less_ current
"restricted" since they move less air, so they are doing less work.
Counter-intuitive, but often true. Toss on a meter and try it. I think
it was Bruce who mentioned that many people kill furnace blowers by
"unrestricting" ductwork to the point that the motors overload...

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

On 7/11/2013 8:49 AM, Ecnerwal wrote:
In , wrote:

Are they open-flow or is there air blockage via a damper system or
discharge/intake louvers or the like? That could drastically raise the
flow restriction and raise motor loading if designed/sized solely for
open unrestricted flow...

Careful with the assumption here - many fans draw _less_ current
"restricted" since they move less air, so they are doing less work.
Counter-intuitive, but often true. Toss on a meter and try it. I think
it was Bruce who mentioned that many people kill furnace blowers by
"unrestricting" ductwork to the point that the motors overload...

Depends on whether the restriction raises head pressure significantly...

--

"dpb" wrote in message
...
On 7/11/2013 8:49 AM, Ecnerwal wrote:
In ,
wrote:

Are they open-flow or is there air blockage via a damper system or
discharge/intake louvers or the like? That could drastically
raise the
flow restriction and raise motor loading if designed/sized solely
for
open unrestricted flow...

Careful with the assumption here - many fans draw _less_ current
"restricted" since they move less air, so they are doing less work.
Counter-intuitive, but often true. Toss on a meter and try it. I
think
it was Bruce who mentioned that many people kill furnace blowers by
"unrestricting" ductwork to the point that the motors overload...

Depends on whether the restriction raises head pressure
significantly...

Really on if the blades have stalled.

On 7/11/2013 11:14 AM, Jim Wilkins wrote:
wrote in message
...
On 7/11/2013 8:49 AM, Ecnerwal wrote:
In ,
wrote:

Are they open-flow or is there air blockage via a damper system or
discharge/intake louvers or the like? That could drastically
raise the
flow restriction and raise motor loading if designed/sized solely
for
open unrestricted flow...

Careful with the assumption here - many fans draw _less_ current
"restricted" since they move less air, so they are doing less work.
Counter-intuitive, but often true. Toss on a meter and try it. I
think
it was Bruce who mentioned that many people kill furnace blowers by
"unrestricting" ductwork to the point that the motors overload...

Depends on whether the restriction raises head pressure
significantly...

Really on if the blades have stalled.

And if there's increased head resistance, that's a partial stall...or at
least more work to keep going against it.

LRA is something else again.

Too little to really judge; more useful than pic of a similar used motor
from and eBay auction would have been pictures of the installation and
links to the vendor of the fans and specific model to see what the app
looks like as opposed to what the vendor spec'ed and the like.

--

--

"dpb" wrote in message
...
On 7/11/2013 11:14 AM, Jim Wilkins wrote:

Really on if the blades have stalled.

And if there's increased head resistance, that's a partial
stall...or at least more work to keep going against it.


Just checked with a Kill-A-Watt. A muffin-sized centrifugal blower
draws 24W open, 18W with either the intake or exhaust blocked.
jsw

On 7/11/2013 12:22 PM, Jim Wilkins wrote:
....

Just checked with a Kill-A-Watt. A muffin-sized centrifugal blower
draws 24W open, 18W with either the intake or exhaust blocked.

OK, let's recast what I was driving at...you're saying there's no fan
curve/as-shipped design point for which it's possible the OP has done
something to his ducting or louvers or the like that can result in
raising motor load above design so he shouldn't/needn't consider that as
a possible root cause/factor?

--

"dpb" wrote in message
...
On 7/11/2013 12:22 PM, Jim Wilkins wrote:
Just checked with a Kill-A-Watt. A muffin-sized centrifugal blower
draws 24W open, 18W with either the intake or exhaust blocked.

OK, let's recast what I was driving at...you're saying there's no
fan curve/as-shipped design point for which it's possible the OP has
done something to his ducting or louvers or the like that can result
in raising motor load above design so he shouldn't/needn't consider
that as a possible root cause/factor?

You said that, not me. I posted only the free-flow and fully blocked
readings for a small impedance-protected motor that doesn't represent
the loading curve of a larger one. The shape of the blades strongly
affects the pressure the fan can produce and the full-load power.
You'd need a wattmeter and a gage like this:
http://www.dwyer-inst.com/Product/Pr...ges/Series2000
to determine the conditions of that specific installation. I've done
it for the cooling fan for vacuum tube and solid-state radio
transmitters, not for HVAC.
jsw

On 7/11/2013 4:54 PM, Jim Wilkins wrote:
....

... I posted only the free-flow and fully blocked
readings for a small impedance-protected motor that doesn't represent
the loading curve of a larger one. The shape of the blades strongly
affects the pressure the fan can produce and the full-load power.
You'd need a wattmeter and a gage like this:
http://www.dwyer-inst.com/Product/Pr...ges/Series2000
to determine the conditions of that specific installation. I've done
it for the cooling fan for vacuum tube and solid-state radio
transmitters, not for HVAC.

So then why are you hounding me over suggesting a possible area for the
OP who's looking into motor problems w/ sizable vent fans in a greenhouse?

I don't have his fan curve; we don't even have pictures of the
installation; all I'm trying to do is give the guy some things to go
investigate that could help him get to the bottom of his problem.

Certainly he needs far more data than has provided here to have any hope
of learning anything specific unless it's truly obvious and then it
would seem would already have known...

--

On Thu, 11 Jul 2013 15:13:27 -0500, dpb wrote:

On 7/11/2013 12:22 PM, Jim Wilkins wrote:
...

Just checked with a Kill-A-Watt. A muffin-sized centrifugal blower
draws 24W open, 18W with either the intake or exhaust blocked.

OK, let's recast what I was driving at...you're saying there's no fan
curve/as-shipped design point for which it's possible the OP has done
something to his ducting or louvers or the like that can result in
raising motor load above design so he shouldn't/needn't consider that as
a possible root cause/factor?
I'd say that sounds right. Short of physical restriction (drag) it
is difficult to overload a fan. Restricted air flow COULD possibly
cause a fan motor to everheat due to reduced cooling, but not due to
increased load.

"dpb" wrote in message
...
On 7/11/2013 4:54 PM, Jim Wilkins wrote:
dpb" wrote
OK, let's recast what I was driving at...you're saying there's no
fan curve/as-shipped design point for which it's possible the OP
has done something to his ducting or louvers or the like that can
result in raising motor load above design so he shouldn't/needn't
consider that as a possible root cause/factor?

... I posted only the free-flow and fully blocked
readings for a small impedance-protected motor that doesn't
represent
the loading curve of a larger one.

So then why are you hounding me over suggesting a possible area for
the OP who's looking into motor problems w/ sizable vent fans in a
greenhouse?

Hounding you???
jsw

On Wed, 10 Jul 2013 14:09:24 -0500, Karl Townsend wrote:

I have pretty much the same thing in my house. i think the motors are
20 years ould now.

Very unlikely to have that many defective motors. I'd look to another
problem in mounting or gearing. My first guess would be the motor is
too small for the pulley gearing you have, check a new one with an amp
meter and see if its pulling more than name plate. If so, change
pulleys or go to larger motor.

Also possilbe that mounting is poor taking the bearings out.

I suppose you'de know it you have low voltage problems at your site.
Even occasionally kills motors.

Karl

House voltage is running a little above 120V; low voltage does not
seem to be the issue.

A meter suggests that the fans are drawing 5.5A to 7A; the latter
number is right up toward the nameplate rating but not way over it.

Some more background, in case it suggests anything:

The salesman who sold us the greenhouse ordered fans with 220V motors
for it, even though he had ordered a 120V controller system. He then
tried to correct it by ordering new motors only, not complete new fan
setups.

The motors were changed on-site by the local electrician who was
putting the system together.

So it is certainly conceivable that the belts may be too loose or too
tight. I have no sure-fire way to know what the right tension is; they
are tight enough that the belt doesn't flap; the adjustment method is
so awkward that having the belts too loose seems to be more likely
than too tight.

It is also possible that the pulleys are not right in some way. My
understanding is that they are the original pulleys from the original
motors that were nominally the same HP rating...

Some other sort of problem that I haven't thought of is also possible.

Bob

On Wed, 10 Jul 2013 15:17:08 -0500, dpb wrote:

On 7/10/2013 1:14 PM, Bob S wrote:

I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. ...

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson
Model S63ZZJKW-7333
HP 1/2 RPM 1725/1140 SF 1.3
V 115 Hz 60 PH 1 Code L
A 7.2 SFA 9.5 AMB 40C
Made in Mexico
...

I'm agreeing w/ Karl; Emerson isn't just some generic import Chinese
no-name; generally while they're assembled in Mexico they're good stuff.

A couple of other thoughts -- it's "humid" environment--any chance it's
actually condensing environment and you're drowning them in internal
condensate? Or are they getting wet from watering system or outside?

On mounting, they're not designed for anything except horizontal so if
even slightly off that'll be very bad on bearings.

Are they open-flow or is there air blockage via a damper system or
discharge/intake louvers or the like? That could drastically raise the
flow restriction and raise motor loading if designed/sized solely for
open unrestricted flow...

What does the vendor say? Surely they can't be happy replacing them
this frequently if is under warranty?


I am not watering the fans from either side. The installation is a
standard type of greenhouse setup; they should not be seeing any more
water or condensation than usual.

The mounting is slanted. Again, this is the standard way of installing
this fan setup, so I assume the vendor selected motors with this in
mind.

The system has the standard louvers opened by air flow.

The vendor does not seem to be happy, but so far they have not offered
any ideas...

Bob

On Sat, 13 Jul 2013 18:18:23 -0400, Bob S
wrote:



On Wed, 10 Jul 2013 14:09:24 -0500, Karl Townsend wrote:

I have pretty much the same thing in my house. i think the motors are
20 years ould now.

Very unlikely to have that many defective motors. I'd look to another
problem in mounting or gearing. My first guess would be the motor is
too small for the pulley gearing you have, check a new one with an amp
meter and see if its pulling more than name plate. If so, change
pulleys or go to larger motor.

Also possilbe that mounting is poor taking the bearings out.

I suppose you'de know it you have low voltage problems at your site.
Even occasionally kills motors.

Karl

House voltage is running a little above 120V; low voltage does not
seem to be the issue.

A meter suggests that the fans are drawing 5.5A to 7A; the latter
number is right up toward the nameplate rating but not way over it.

Some more background, in case it suggests anything:

The salesman who sold us the greenhouse ordered fans with 220V motors
for it, even though he had ordered a 120V controller system. He then
tried to correct it by ordering new motors only, not complete new fan
setups.

The motors were changed on-site by the local electrician who was
putting the system together.

So it is certainly conceivable that the belts may be too loose or too
tight. I have no sure-fire way to know what the right tension is; they
are tight enough that the belt doesn't flap; the adjustment method is
so awkward that having the belts too loose seems to be more likely
than too tight.

It is also possible that the pulleys are not right in some way. My
understanding is that they are the original pulleys from the original
motors that were nominally the same HP rating...

Some other sort of problem that I haven't thought of is also possible.

Bob

You would have been WAY better off staying with 220 volt motors. This
is likely the design problem. A 220 volt motor has exactly half the
current and runs much cooler.

Surely, your control system just closes a relay (or motor starter
relay) so you can run either voltage on the motor. You sound like
you're not a EE type, most any competant electrician knows how to
easily do this with hardly any rewiring.


If you want to stay with the 120 volt setup at this point, my best
guess would be to slow the fans down 20 or 25% with a pulley change.
Keep in mind your amp test was only at one point in time, there are
likely periods where combinations of heat, humidity, and wind are
overloading them.

Good luck,

Karl

On Sun, 14 Jul 2013 03:35:51 -0500, Karl Townsend
wrote:

On Sat, 13 Jul 2013 18:18:23 -0400, Bob S
wrote:



On Wed, 10 Jul 2013 14:09:24 -0500, Karl Townsend wrote:

I have pretty much the same thing in my house. i think the motors are
20 years ould now.

Very unlikely to have that many defective motors. I'd look to another
problem in mounting or gearing. My first guess would be the motor is
too small for the pulley gearing you have, check a new one with an amp
meter and see if its pulling more than name plate. If so, change
pulleys or go to larger motor.

Also possilbe that mounting is poor taking the bearings out.

I suppose you'de know it you have low voltage problems at your site.
Even occasionally kills motors.

Karl

House voltage is running a little above 120V; low voltage does not
seem to be the issue.

A meter suggests that the fans are drawing 5.5A to 7A; the latter
number is right up toward the nameplate rating but not way over it.

Some more background, in case it suggests anything:

The salesman who sold us the greenhouse ordered fans with 220V motors
for it, even though he had ordered a 120V controller system. He then
tried to correct it by ordering new motors only, not complete new fan
setups.

The motors were changed on-site by the local electrician who was
putting the system together.

So it is certainly conceivable that the belts may be too loose or too
tight. I have no sure-fire way to know what the right tension is; they
are tight enough that the belt doesn't flap; the adjustment method is
so awkward that having the belts too loose seems to be more likely
than too tight.

It is also possible that the pulleys are not right in some way. My
understanding is that they are the original pulleys from the original
motors that were nominally the same HP rating...

Some other sort of problem that I haven't thought of is also possible.

Bob

You would have been WAY better off staying with 220 volt motors. This
is likely the design problem. A 220 volt motor has exactly half the
current and runs much cooler.

Surely, your control system just closes a relay (or motor starter
relay) so you can run either voltage on the motor. You sound like
you're not a EE type, most any competant electrician knows how to
easily do this with hardly any rewiring.


If you want to stay with the 120 volt setup at this point, my best
guess would be to slow the fans down 20 or 25% with a pulley change.
Keep in mind your amp test was only at one point in time, there are
likely periods where combinations of heat, humidity, and wind are
overloading them.

Good luck,

Karl

Good advice Karl!


--
""Almost all liberal behavioral tropes track the impotent rage of small
children. Thus, for example, there is also the popular tactic of
repeating some stupid, meaningless phrase a billion times" Arms for
hostages, arms for hostages, arms for hostages, it's just about sex, just
about sex, just about sex, dumb,dumb, money in politics,money in
politics, Enron, Enron, Enron. Nothing repeated with mind-numbing
frequency in all major news outlets will not be believed by some members
of the populace. It is the permanence of evil; you can't stop it." (Ann
Coulter)

On Sun, 14 Jul 2013 03:35:51 -0500, Karl Townsend
wrote:

On Sat, 13 Jul 2013 18:18:23 -0400, Bob S
wrote:



On Wed, 10 Jul 2013 14:09:24 -0500, Karl Townsend wrote:

I have pretty much the same thing in my house. i think the motors are
20 years ould now.

Very unlikely to have that many defective motors. I'd look to another
problem in mounting or gearing. My first guess would be the motor is
too small for the pulley gearing you have, check a new one with an amp
meter and see if its pulling more than name plate. If so, change
pulleys or go to larger motor.

Also possilbe that mounting is poor taking the bearings out.

I suppose you'de know it you have low voltage problems at your site.
Even occasionally kills motors.

Karl

House voltage is running a little above 120V; low voltage does not
seem to be the issue.

A meter suggests that the fans are drawing 5.5A to 7A; the latter
number is right up toward the nameplate rating but not way over it.

Some more background, in case it suggests anything:

The salesman who sold us the greenhouse ordered fans with 220V motors
for it, even though he had ordered a 120V controller system. He then
tried to correct it by ordering new motors only, not complete new fan
setups.

The motors were changed on-site by the local electrician who was
putting the system together.

So it is certainly conceivable that the belts may be too loose or too
tight. I have no sure-fire way to know what the right tension is; they
are tight enough that the belt doesn't flap; the adjustment method is
so awkward that having the belts too loose seems to be more likely
than too tight.

It is also possible that the pulleys are not right in some way. My
understanding is that they are the original pulleys from the original
motors that were nominally the same HP rating...

Some other sort of problem that I haven't thought of is also possible.

Bob

You would have been WAY better off staying with 220 volt motors. This
is likely the design problem. A 220 volt motor has exactly half the
current and runs much cooler.


Not necessarily. The wattage is the same. 110 just needs heavier
wiring to frrd the motor. The motor efficiency is generally pretty
much a "wash"
Surely, your control system just closes a relay (or motor starter
relay) so you can run either voltage on the motor. You sound like
you're not a EE type, most any competant electrician knows how to
easily do this with hardly any rewiring.


If you want to stay with the 120 volt setup at this point, my best
guess would be to slow the fans down 20 or 25% with a pulley change.
Keep in mind your amp test was only at one point in time, there are
likely periods where combinations of heat, humidity, and wind are
overloading them.

better ratio would likely HELP the situation. It may not be the cure.
Also, being BELT DRIVE fans, where is the motor mounted? Is it in the
air stream???? Generally motors without venting or fans are used in
direct drive fans.

Good luck,

Karl

On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

On Sun, 14 Jul 2013 13:57:35 -0400, wrote:

On Sun, 14 Jul 2013 03:35:51 -0500, Karl Townsend
wrote:

On Sat, 13 Jul 2013 18:18:23 -0400, Bob S
wrote:



On Wed, 10 Jul 2013 14:09:24 -0500, Karl Townsend wrote:

I have pretty much the same thing in my house. i think the motors are
20 years ould now.

Very unlikely to have that many defective motors. I'd look to another
problem in mounting or gearing. My first guess would be the motor is
too small for the pulley gearing you have, check a new one with an amp
meter and see if its pulling more than name plate. If so, change
pulleys or go to larger motor.

Also possilbe that mounting is poor taking the bearings out.

I suppose you'de know it you have low voltage problems at your site.
Even occasionally kills motors.

Karl

House voltage is running a little above 120V; low voltage does not
seem to be the issue.

A meter suggests that the fans are drawing 5.5A to 7A; the latter
number is right up toward the nameplate rating but not way over it.

Some more background, in case it suggests anything:

The salesman who sold us the greenhouse ordered fans with 220V motors
for it, even though he had ordered a 120V controller system. He then
tried to correct it by ordering new motors only, not complete new fan
setups.

The motors were changed on-site by the local electrician who was
putting the system together.

So it is certainly conceivable that the belts may be too loose or too
tight. I have no sure-fire way to know what the right tension is; they
are tight enough that the belt doesn't flap; the adjustment method is
so awkward that having the belts too loose seems to be more likely
than too tight.

It is also possible that the pulleys are not right in some way. My
understanding is that they are the original pulleys from the original
motors that were nominally the same HP rating...

Some other sort of problem that I haven't thought of is also possible.

Bob

You would have been WAY better off staying with 220 volt motors. This
is likely the design problem. A 220 volt motor has exactly half the
current and runs much cooler.


Not necessarily. The wattage is the same. 110 just needs heavier
wiring to frrd the motor. The motor efficiency is generally pretty
much a "wash"
Surely, your control system just closes a relay (or motor starter
relay) so you can run either voltage on the motor. You sound like
you're not a EE type, most any competant electrician knows how to
easily do this with hardly any rewiring.


If you want to stay with the 120 volt setup at this point, my best
guess would be to slow the fans down 20 or 25% with a pulley change.
Keep in mind your amp test was only at one point in time, there are
likely periods where combinations of heat, humidity, and wind are
overloading them.

better ratio would likely HELP the situation. It may not be the cure.
Also, being BELT DRIVE fans, where is the motor mounted? Is it in the
air stream???? Generally motors without venting or fans are used in
direct drive fans.

Good luck,

Karl


Yes, there is a large contactor box, and yes it would seem as though
220V would have been feasible.

The installation was done by professional electricians; perhaps if I
had been doing it I might have made different choices.

I suppose that if the wire size were the same then a 220V motor would
have less loss, but I suspect that the maker uses a smaller size wire
and ends up with about the same waste heat.

The pulley change is an interesting idea; I should look into that. I
don't know what the curves look like for these propeller fans, but I
assume that slowing down the fans would reduce the load on the motors
and might cause them to last longer. It would have to make them last a
LOT longer to be really useful.

The motor is mounted above the fan hub, and is directly in the air
stream, so it is getting as much cooling as it could ever hope for.

Bob

On Wednesday, July 17, 2013 2:38:21 PM UTC-4, Bob S wrote:





The pulley change is an interesting idea; I should look into that. I

don't know what the curves look like for these propeller fans, but I

assume that slowing down the fans would reduce the load on the motors

and might cause them to last longer. It would have to make them last a

LOT longer to be really useful.




Bob

The simple calculations shown in the Grainger catalog shows the hp required varies withe Cube of the speed. Their example shows increasing the rpm from 5000 to 6000 requires 1.73 times as much hp. So reducing the speed a little will have a large effect on the hp and life.

Dan

Bob S laid this down on his screen :
On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

Bob, I dont think you have ever really told us how these motors fail.
You seem to be saying that it might be bearing failure.
Then all the discussion about current, voltage etc is wasted.
Motor bearings last for decades if rated and cooled correctly.
Are yours cool?
Is there an undue side load? eg belts too tight.
Is the atmosphers corrosive?

--
John G

On Wed, 17 Jul 2013 14:27:18 -0400, Bob S
wrote:

On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

3/4hp? I thought they were 1/3 hp?

Running a belt and in the airstream, check. Thats good.

No cap? Not very many single phase motors of that size, dont have
start/run caps. Sure there arent any inclosed in the fan housing
somewhere?

http://www.capacitorformotor.com/start_cap.html

As for no lube points...I think Id pull down a motor and check. Some
indeed are "permanantly lubricated" on the name plate. But I think Id
look for either plugs in the end bearing covers or little holes that
you can spritz oil into the bearings.

Id also take a volt meter and put it on the fan circuit (s) somewhere
and check your voltage on both the line and on the input to each fan
occasionally. You said that there were several that were running
slow...thats either a sign of bearings about to freeze up, shorted
windings, low voltage at the motor...or bad run caps or even bad start
caps on some..some motors.

Get some measurements and you might determine whats going on.

Gunner


--
""Almost all liberal behavioral tropes track the impotent rage of small
children. Thus, for example, there is also the popular tactic of
repeating some stupid, meaningless phrase a billion times" Arms for
hostages, arms for hostages, arms for hostages, it's just about sex, just
about sex, just about sex, dumb,dumb, money in politics,money in
politics, Enron, Enron, Enron. Nothing repeated with mind-numbing
frequency in all major news outlets will not be believed by some members
of the populace. It is the permanence of evil; you can't stop it." (Ann
Coulter)

On Wed, 17 Jul 2013 23:17:25 -0700, Gunner Asch
wrote:

On Wed, 17 Jul 2013 14:27:18 -0400, Bob S
wrote:

On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

3/4hp? I thought they were 1/3 hp?

Reviewing the data..they are 1/2 hp


Running a belt and in the airstream, check. Thats good.

No cap? Not very many single phase motors of that size, dont have
start/run caps. Sure there arent any inclosed in the fan housing
somewhere?

http://www.capacitorformotor.com/start_cap.html

As for no lube points...I think Id pull down a motor and check. Some
indeed are "permanantly lubricated" on the name plate. But I think Id
look for either plugs in the end bearing covers or little holes that
you can spritz oil into the bearings.

Id also take a volt meter and put it on the fan circuit (s) somewhere
and check your voltage on both the line and on the input to each fan
occasionally. You said that there were several that were running
slow...thats either a sign of bearings about to freeze up, shorted
windings, low voltage at the motor...or bad run caps or even bad start
caps on some..some motors.

Get some measurements and you might determine whats going on.

Gunner

--
""Almost all liberal behavioral tropes track the impotent rage of small
children. Thus, for example, there is also the popular tactic of
repeating some stupid, meaningless phrase a billion times" Arms for
hostages, arms for hostages, arms for hostages, it's just about sex, just
about sex, just about sex, dumb,dumb, money in politics,money in
politics, Enron, Enron, Enron. Nothing repeated with mind-numbing
frequency in all major news outlets will not be believed by some members
of the populace. It is the permanence of evil; you can't stop it." (Ann
Coulter)

On Thu, 18 Jul 2013 10:11:28 +1000, John G wrote:

Bob S laid this down on his screen :
On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

Bob, I dont think you have ever really told us how these motors fail.
You seem to be saying that it might be bearing failure.
Then all the discussion about current, voltage etc is wasted.
Motor bearings last for decades if rated and cooled correctly.
Are yours cool?
Is there an undue side load? eg belts too tight.
Is the atmosphers corrosive?

There are two different failure modes.

One mode is that the motor is extremely rough-starting on low speed.
It is rough enough to shake the greenhouse structure. It seems as
though the torque is shifting rapidly from high to low and back again,
which I take to mean that the starter circuit is cutting in and out,
which in turn I take to mean that either the motor starter is
defective or the motor does not have enough power to accelerate the
fan.


The other failure mode is that the motor runs unreasonably slowly. The
motor may run at full speed when new, but before very long it gets
slower and never runs at full speed again.

The bearings do not seem to be seized up, they do not seem to have
excessive friction, they do not make noises.



Coolness is relative... The motors are not running hot enough to raise
immediate blisters if I touch the casing, but I would not want to
leave my hand pressed firmly against the casing for very long.


Belt tightness: If I push on them they move inward a short distance.
They are not loose enough to flap around and not tight enough to go
"twang". They seem of ordinary tightness to me. I have no
specification and no way of measuring it anyway.


Corrosive atmosphere? Well, it is a greenhouse, there is a lot of
moisture in the air, fertilizers and occasional insecticides are used.
The fans are sold specifically for greenhouse use and the company is
well-known and has been around for a long time, so I can only hope
that they have designed with the environment in mind.



Bob

On Wed, 17 Jul 2013 23:49:46 -0700, Gunner Asch wrote:

On Wed, 17 Jul 2013 23:17:25 -0700, Gunner Asch
wrote:

On Wed, 17 Jul 2013 14:27:18 -0400, Bob S
wrote:

On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

3/4hp? I thought they were 1/3 hp?

Reviewing the data..they are 1/2 hp


Running a belt and in the airstream, check. Thats good.

No cap? Not very many single phase motors of that size, dont have
start/run caps. Sure there arent any inclosed in the fan housing
somewhere?

http://www.capacitorformotor.com/start_cap.html

As for no lube points...I think Id pull down a motor and check. Some
indeed are "permanantly lubricated" on the name plate. But I think Id
look for either plugs in the end bearing covers or little holes that
you can spritz oil into the bearings.

Id also take a volt meter and put it on the fan circuit (s) somewhere
and check your voltage on both the line and on the input to each fan
occasionally. You said that there were several that were running
slow...thats either a sign of bearings about to freeze up, shorted
windings, low voltage at the motor...or bad run caps or even bad start
caps on some..some motors.

Get some measurements and you might determine whats going on.

Gunner


Right, 1/2 HP rating.

I am wondering whether that is really enough to drive a 36 inch fan at
the speed it is trying to go.

The voltage seems to be fine, I have looked a couple times. The
current is running right up to the nameplate rating, so there is
certainly no spare capacity in the motor.

Bob

On Thu, 18 Jul 2013 17:16:48 -0400, Bob S
wrote:

On Wed, 17 Jul 2013 23:49:46 -0700, Gunner Asch wrote:

On Wed, 17 Jul 2013 23:17:25 -0700, Gunner Asch
wrote:

On Wed, 17 Jul 2013 14:27:18 -0400, Bob S
wrote:

On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

3/4hp? I thought they were 1/3 hp?

Reviewing the data..they are 1/2 hp


Running a belt and in the airstream, check. Thats good.

No cap? Not very many single phase motors of that size, dont have
start/run caps. Sure there arent any inclosed in the fan housing
somewhere?

http://www.capacitorformotor.com/start_cap.html

As for no lube points...I think Id pull down a motor and check. Some
indeed are "permanantly lubricated" on the name plate. But I think Id
look for either plugs in the end bearing covers or little holes that
you can spritz oil into the bearings.

Id also take a volt meter and put it on the fan circuit (s) somewhere
and check your voltage on both the line and on the input to each fan
occasionally. You said that there were several that were running
slow...thats either a sign of bearings about to freeze up, shorted
windings, low voltage at the motor...or bad run caps or even bad start
caps on some..some motors.

Get some measurements and you might determine whats going on.

Gunner


Right, 1/2 HP rating.

I am wondering whether that is really enough to drive a 36 inch fan at
the speed it is trying to go.

The voltage seems to be fine, I have looked a couple times. The
current is running right up to the nameplate rating, so there is
certainly no spare capacity in the motor.

Bob

Im going out on a limb here and saying the motor is too small or its
geared too high. Probably geared too high would be my guess..

Ive put a lot of motors into machinery over the years..and a 1/2hp
motor seems a bit small for a 36" fan run at "high speeds"...but its
not part of my expertise. That being said..Ive got pedestal fans out
in the shop that are spinning 36" fans out in the shop on 1/2 hp
motors..but they are turning fairly slowly and are direct drive with
no venturi effect.

Mine are all about 1500 rpm if I recall correctely.


Gunner

--
""Almost all liberal behavioral tropes track the impotent rage of small
children. Thus, for example, there is also the popular tactic of
repeating some stupid, meaningless phrase a billion times" Arms for
hostages, arms for hostages, arms for hostages, it's just about sex, just
about sex, just about sex, dumb,dumb, money in politics,money in
politics, Enron, Enron, Enron. Nothing repeated with mind-numbing
frequency in all major news outlets will not be believed by some members
of the populace. It is the permanence of evil; you can't stop it." (Ann
Coulter)

Bob S brought next idea :
On Thu, 18 Jul 2013 10:11:28 +1000, John G wrote:

Bob S laid this down on his screen :
On Fri, 12 Jul 2013 22:48:27 -0700, Gunner Asch wrote:

On Wed, 10 Jul 2013 14:14:03 -0400, Bob S
wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

That motor has Zero cooling. Notice..no internal or external fan on
it?

While it SHOULD provide its own cooling with the external fan...often
times they dont cool very well because of the design of the center hub
of the fan. The motor often times runs in a "dead air space"

Id consider getting a different style motor with an external fan. As
for the fan running slowly..that could be for several reasons.

1. Do you lubricate them properly and regularly?
2. Are the run caps going bad?
3. Is the start caps going bad?

http://www.coleparmer.com/buy/category/motor-1-3-hp

4. Are the motors actually the right hp for the load? Would a 1/2hp
motor be more appropriate?

Gunner

Thank you for the ideas.

The motor is positioned above the fan hub, connected by a belt, and is
actually in the air stream. Whether the cooling is adequate only the
designer knows, but it is not obstructed at least.

The motor name plate says that the motor bearings are permanently
lubricated. Is suspect that the fan hub also uses permanently
lubricated bearings, mostly because there were no lubrication
instructions provided and there are no oiling points. The bearing
housing for the fan hub is a good-sized chunk of hex stock open only
at one end.

The motor does not have an external "wart" for a capacitor. If there
are any capacitors present then they are concealed inside the
cylindrical housing somewhere.

The motors are 3/4HP, which seems to be the size that this company
suggests for a 36 inch fan.

Bob

Bob, I dont think you have ever really told us how these motors fail.
You seem to be saying that it might be bearing failure.
Then all the discussion about current, voltage etc is wasted.
Motor bearings last for decades if rated and cooled correctly.
Are yours cool?
Is there an undue side load? eg belts too tight.
Is the atmosphers corrosive?

There are two different failure modes.

One mode is that the motor is extremely rough-starting on low speed.
It is rough enough to shake the greenhouse structure. It seems as
though the torque is shifting rapidly from high to low and back again,
which I take to mean that the starter circuit is cutting in and out,
which in turn I take to mean that either the motor starter is
defective or the motor does not have enough power to accelerate the
fan.


The other failure mode is that the motor runs unreasonably slowly. The
motor may run at full speed when new, but before very long it gets
slower and never runs at full speed again.

The bearings do not seem to be seized up, they do not seem to have
excessive friction, they do not make noises.

Coolness is relative... The motors are not running hot enough to raise
immediate blisters if I touch the casing, but I would not want to
leave my hand pressed firmly against the casing for very long.

Belt tightness: If I push on them they move inward a short distance.
They are not loose enough to flap around and not tight enough to go
"twang". They seem of ordinary tightness to me. I have no
specification and no way of measuring it anyway.

Corrosive atmosphere? Well, it is a greenhouse, there is a lot of
moisture in the air, fertilizers and occasional insecticides are used.
The fans are sold specifically for greenhouse use and the company is
well-known and has been around for a long time, so I can only hope
that they have designed with the environment in mind.
Bob

What does the Company say? He should have better knowledge than we can.

Have you tried running with the belt off? That should give you an idea
if they are overloaded.
Do the pulleys increase the speed or decrease it at the fan? IE what's
the ratio?
You should be able to get the expected temp rise from the motor specs.

Progressive failure as you describe sounds very strange. There really
should be some failure to observe and fix.

--
John G

On Thu, 11 Jul 2013 22:39:38 -0400, wrote:

On Thu, 11 Jul 2013 15:13:27 -0500, dpb wrote:

On 7/11/2013 12:22 PM, Jim Wilkins wrote:
...

Just checked with a Kill-A-Watt. A muffin-sized centrifugal blower
draws 24W open, 18W with either the intake or exhaust blocked.

OK, let's recast what I was driving at...you're saying there's no fan
curve/as-shipped design point for which it's possible the OP has done
something to his ducting or louvers or the like that can result in
raising motor load above design so he shouldn't/needn't consider that as
a possible root cause/factor?
I'd say that sounds right. Short of physical restriction (drag) it
is difficult to overload a fan. Restricted air flow COULD possibly
cause a fan motor to everheat due to reduced cooling, but not due to
increased load.

Muffin fan motors are simple shaded-pole driving a small blade, not an
induction driving a large blade.

It's easy to rig a belt-drive so the motor is overloaded - You have
to look at the Full Load Amps and the Service Factor, and make sure
the actual draw is under the nameplate ratings. If it's not, you have
to make the motor pulley smaller to drop the fan speed and the load.

If it doesn't have the variable-diameter pullies, you need to add
them. Or you have them and they've rusted solid at the old setting,
which means dismantle and derust.

And check the line voltage available at the fan motors - If they are
120V motors, anything below 110V is trouble. You could have a bad
wirenut that has rusted out halfway to the greenhouse too. This is
why they use the 240V motors - half the current means half the voltage
drop. You might have 120V at the house, but the Greenhouse is 250'
from the house which means 500' of wire...

If the pipe is big enough you can run #6 Copper or #4 Aluminum wire
and solve the voltage drop issues - if it's 1/2" conduit and already
at fill, you'll need to bump the voltage up instead.

On Fri, 19 Jul 2013 15:59:29 -0700, "Bruce L. Bergman (munged human
readable)" wrote:

On Thu, 11 Jul 2013 22:39:38 -0400, wrote:

On Thu, 11 Jul 2013 15:13:27 -0500, dpb wrote:

On 7/11/2013 12:22 PM, Jim Wilkins wrote:
...

Just checked with a Kill-A-Watt. A muffin-sized centrifugal blower
draws 24W open, 18W with either the intake or exhaust blocked.

OK, let's recast what I was driving at...you're saying there's no fan
curve/as-shipped design point for which it's possible the OP has done
something to his ducting or louvers or the like that can result in
raising motor load above design so he shouldn't/needn't consider that as
a possible root cause/factor?
I'd say that sounds right. Short of physical restriction (drag) it
is difficult to overload a fan. Restricted air flow COULD possibly
cause a fan motor to everheat due to reduced cooling, but not due to
increased load.

Muffin fan motors are simple shaded-pole driving a small blade, not an
induction driving a large blade.

It's easy to rig a belt-drive so the motor is overloaded - You have
to look at the Full Load Amps and the Service Factor, and make sure
the actual draw is under the nameplate ratings. If it's not, you have
to make the motor pulley smaller to drop the fan speed and the load.

If it doesn't have the variable-diameter pullies, you need to add
them. Or you have them and they've rusted solid at the old setting,
which means dismantle and derust.

And check the line voltage available at the fan motors - If they are
120V motors, anything below 110V is trouble. You could have a bad
wirenut that has rusted out halfway to the greenhouse too. This is
why they use the 240V motors - half the current means half the voltage
drop. You might have 120V at the house, but the Greenhouse is 250'
from the house which means 500' of wire...

If the pipe is big enough you can run #6 Copper or #4 Aluminum wire
and solve the voltage drop issues - if it's 1/2" conduit and already
at fill, you'll need to bump the voltage up instead.
Are these 1725 (1800) rpm motors when 1125 (1200) should be used?

Well, there is some good news. The company is going to send
replacement motors at 3/4 HP rather than 1/2 HP. If it is a simple
overloading issue then maybe that will solve it.

Bob


On Wed, 10 Jul 2013 14:14:03 -0400, Bob S wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

They sent three new motors, rated at 3/4 HP rather than the original
1/2 HP.

They are physically more impressive. They have the same diameter as
the original motors, but they are 9 1/2 inches long rather than 7 1/2
inches long. They also have an external capacitor cover; the original
motors presumably have the capacitor within the motor housing, so the
actual motor part is not as long as it looks.

The new motors are rated at 12 A rather than 7A.

I opened the first box and pulled out the motor, and the shaft was
frozen so it wouldn't even turn. I know that some of you have good
results with these guys, but I have serious doubts about their QC.

The other two motors are installed and running, at least for the first
few days...

Thanks for all the ideas.

Bob




On Mon, 22 Jul 2013 16:46:12 -0400, Bob S wrote:

Well, there is some good news. The company is going to send
replacement motors at 3/4 HP rather than 1/2 HP. If it is a simple
overloading issue then maybe that will solve it.

Bob


On Wed, 10 Jul 2013 14:14:03 -0400, Bob S wrote:


I have a greenhouse with three fans from "American CoolAir".

The problem is that the motors keep failing. At the moment two are
running ridiculously slowly when powered on high speed. The other will
start and run on high speed, but bangs on startup at low speed; it is
as though the starter is kicking in and out.

The company keeps sending replacements, but I would rather have motors
that didn't need replacing. Is it possible to get drop-in replacement
motors that would actually work more-or-less forever?

The environment is not the greatest, with humid air blowing over them
in summer and the motors in cold air and being frozen in winter, but I
have had other appliances in similar conditions that never suffered a
motor failure.


The motor name labels say

Emerson

Model S63ZZJKW-7333

HP 1/2 RPM 1725/1140 SF 1.3

V 115 Hz 60 PH 1 Code L

A 7.2 SFA 9.5 AMB 40C

Made in Mexico



It looks just like the one in this pictu

http://www.federalindustrialsales.co...ph/m1-318.html

I have been through about 7 motors in the past couple years

On Sat, 17 Aug 2013 17:33:57 -0400, Bob S
wrote:


I opened the first box and pulled out the motor, and the shaft was
frozen so it wouldn't even turn. I know that some of you have good
results with these guys, but I have serious doubts about their QC.

Pull off that cover on the ass end and see if the fan is hanging up on
the tail end of the cover.

Ive had a few recently where the handling left something to be desired
where they evidently dropped the motors on the fan housing and bent
the sheet metal. I hammered the sheet metal back in place and they ran
fine



--
""Almost all liberal behavioral tropes track the impotent rage of small
children. Thus, for example, there is also the popular tactic of
repeating some stupid, meaningless phrase a billion times" Arms for
hostages, arms for hostages, arms for hostages, it's just about sex, just
about sex, just about sex, dumb,dumb, money in politics,money in
politics, Enron, Enron, Enron. Nothing repeated with mind-numbing
frequency in all major news outlets will not be believed by some members
of the populace. It is the permanence of evil; you can't stop it." (Ann
Coulter)

On Sat, 17 Aug 2013 19:22:03 -0700, Gunner Asch
wrote:

On Sat, 17 Aug 2013 17:33:57 -0400, Bob S
wrote:


I opened the first box and pulled out the motor, and the shaft was
frozen so it wouldn't even turn. I know that some of you have good
results with these guys, but I have serious doubts about their QC.

Pull off that cover on the ass end and see if the fan is hanging up on
the tail end of the cover.

Ive had a few recently where the handling left something to be desired
where they evidently dropped the motors on the fan housing and bent
the sheet metal. I hammered the sheet metal back in place and they ran
fine

And I've had one where the fan was pressed on too far and rubbing on
the front housing. Eyes open, guys! QC ain't what is used to be.

Any more, "ISO 9001" means 'Someone filled out the right paperwork.'
They can still build 'em wrong, pack 'em wrong, send 'em to the wrong
address, etc. sigh

--
Truth loves to go naked.
--Dr. Thomas Fuller, Gnomologia, 1732

On Sat, 17 Aug 2013 20:57:32 -0700, Larry Jaques
wrote:

On Sat, 17 Aug 2013 19:22:03 -0700, Gunner Asch
wrote:

On Sat, 17 Aug 2013 17:33:57 -0400, Bob S
wrote:


I opened the first box and pulled out the motor, and the shaft was
frozen so it wouldn't even turn. I know that some of you have good
results with these guys, but I have serious doubts about their QC.

Pull off that cover on the ass end and see if the fan is hanging up on
the tail end of the cover.

Ive had a few recently where the handling left something to be desired
where they evidently dropped the motors on the fan housing and bent
the sheet metal. I hammered the sheet metal back in place and they ran
fine

And I've had one where the fan was pressed on too far and rubbing on
the front housing. Eyes open, guys! QC ain't what is used to be.

Any more, "ISO 9001" means 'Someone filled out the right paperwork.'
They can still build 'em wrong, pack 'em wrong, send 'em to the wrong
address, etc. sigh
ISO 9000 just means you are getting the best documented junk you can
buy.

I would look into incorrect application.

If the atmosphere has excessive humidity, salt dust, and such, perhaps
the OP needs to buy totally enclosed hostile duty motors. Also,
possibly, motors are undersized for the fans that they are turning,
and are overloaded.

i