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)