We survived Ike in extremely good shape compared to others in the vicinity.
The only significant problem is the AC unit: the compressor won't come on.

My AC guy swapped out the start & run capacitors, bypassed the relay, and
checked all the obvious stuff. No compressor action. He theorizes that
power-line chatter at the storm's outset could have so confused the aged
system that it committed suicide trying to keep up.

His best guess is a seized compressor piston on this 17-year old, 3-ton,
Trane and he's checking with his buddies for a used condensing unit.

Observations and suggestions would be welcome.

Thanks.

Uncle Monster wrote:

HeyBub wrote:

We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the compressor
won't come on.

My AC guy swapped out the start & run capacitors, bypassed the relay,
and checked all the obvious stuff. No compressor action. He theorizes
that power-line chatter at the storm's outset could have so confused
the aged system that it committed suicide trying to keep up.

His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used condensing
unit.

Observations and suggestions would be welcome.

Thanks.

When you replace your unit, make sure you
have an anti short cycle timer installed.
A newer system and most electronic thermo-
stats have this feature built in. It will
prevent the contactor in the condensing
unit from slamming on and off with power
blinks or someone playing with the temper-
ature adjustment. The timer is inexpensive
and can be added to any AC condenser. I add
timers to all the systems I install if the
feature isn't there already.

http://tinyurl.com/3h4xbe

[8~{} Uncle Monster

Most thermostats, even with that feature, won't protect against power
failure induced short-cycling because they are battery operated --
they'll just keep calling for cooling through the power chatter.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Ken wrote:
HeyBub wrote:
We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the
compressor won't come on. My AC guy swapped out the start & run
capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to keep
up. His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit. Observations and suggestions would be welcome.

Thanks.


Does the fan for the condenser unit start?

No.

Did he measure the voltage at the leads going to the compressor?

Yes

Why did he bypass the relay
(contactor)? Was it not latching up?

Even if the relay latches, the points could be burned, preventing contact.

I know these are fundamental
checks, but you would be surprised at how some pros diagnose a unit.

Well, the first thing he did was test the start capacitor and pronounced it
"marginal." So he replaced it. No joy. That's when he went through the "try
this, test that" mode.

Ralph Mowery wrote:
"HeyBub" wrote in message
m...
We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the compressor
won't come on.

My AC guy swapped out the start & run capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to keep
up. His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit. Observations and suggestions would be welcome.


If he can not get it to run and wants to change to a used unit, get a
new system. The system you have is 17 years old and you will spend a
lot for some used unit.

$750 vs. ~$1700. Just for the condensing unit.

I would guess that you have the split two
piece unit. Get a new air handler to match. The new units will be
more efficient and you want all pieces to match.
Think I would look into a heat pump system. Not too much differance
it that and an air conditioner.

On the other hand, this is hurricane related and subject to complete
reimbursement by Insurance + FEMA assistance. I figure FEMA won't squawk
over a used unit but might balk at a new upgrade.

As an aside, you'd be surprised how much damage you can discover after a
hurricane-related inspection. For example virtually ALL of my 40-year old
window screens were blown out! Instead of rotating on its hinges, the side
door to the garage falls flat on the ground. Two of my cats had to have
intense psychological therapy.

As I understand it, FEMA will cover your deductible plus any unrecovered
insurance expenses (spoiled food, gas for the generator, etc.). If you have
no insurance, FEMA will cover the whole expense (up to $28,800).

HeyBub wrote:
Ken wrote:
HeyBub wrote:
We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the
compressor won't come on. My AC guy swapped out the start & run
capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to keep
up. His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit. Observations and suggestions would be welcome.

Thanks.


Does the fan for the condenser unit start?

No.

Your condenser unit may be different, but many have the fan motor wired
in parallel to the compressor. In other words, when power is applied to
the compressor it is also applied to the fan motor. Having them both
fail at the same time is very unlikely. Check to see if they are wired
in parallel and make sure you are getting power applied to these units
when the contactor is latched.

Did he measure the voltage at the leads going to the compressor?

Yes

And it was 220/240 volts? See above comment.

Why did he bypass the relay
(contactor)? Was it not latching up?

Even if the relay latches, the points could be burned, preventing contact.

True, but one would only do this if there was not proper power applied
to the compressor and fan motor.




I know these are fundamental
checks, but you would be surprised at how some pros diagnose a unit.

Well, the first thing he did was test the start capacitor and pronounced it
"marginal." So he replaced it. No joy. That's when he went through the "try
this, test that" mode.

Does the man own an ammeter? Very useful in such cases. Clean the terminals
on top of the compressor. Try starting it again, and check the amp draw.
Might be bad compressor, or just dirty terminals. Is the compressor really
getting 220 volts?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"HeyBub" wrote in message
m...
We survived Ike in extremely good shape compared to others in the vicinity.
The only significant problem is the AC unit: the compressor won't come on.

My AC guy swapped out the start & run capacitors, bypassed the relay, and
checked all the obvious stuff. No compressor action. He theorizes that
power-line chatter at the storm's outset could have so confused the aged
system that it committed suicide trying to keep up.

His best guess is a seized compressor piston on this 17-year old, 3-ton,
Trane and he's checking with his buddies for a used condensing unit.

Observations and suggestions would be welcome.

Thanks.

Does the fan for the condenser unit start?

No.

CY: Unlikely to lose the comp and the fan both. Maybe bad relay.

Did he measure the voltage at the leads going to the compressor?

Yes

CY: And got what results?

Why did he bypass the relay
(contactor)? Was it not latching up?

Even if the relay latches, the points could be burned, preventing contact.

CY: That's true. How about the power safety disconnect? Working properly?
Sometimes those corrode.

I know these are fundamental
checks, but you would be surprised at how some pros diagnose a unit.

Well, the first thing he did was test the start capacitor and pronounced it
"marginal." So he replaced it. No joy. That's when he went through the "try
this, test that" mode.

CY: Amp draw check is important. Also continuity across the compressor
terminals.

Ralph Mowery wrote:

"HeyBub" wrote in message new system. The
system you have is 17 years old and you will spend a

lot for some used unit.

$750 vs. ~$1700. Just for the condensing unit.


YOu can either spend that money now or in a few years spend the money for a
new unit. Don't just get the condensing unit, but a whole new matching
system. You probably will save money on the power in the long run to make
up the differance.

That will almost certainly never happen. Do the math. If the
difference is $4k, and you spend $400/year on A/C electricity
costs, you'd have to drive those electricity costs to zero in
order to merely cover the interest on the $4K at 10%. It won't
happen.

Just plan on spending around $ 5000 for whole new
system.

If you are planning on moving out in a few years, then it may pay you to do
just a patch job.





--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

CJT wrote:
Uncle Monster wrote:

HeyBub wrote:

We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the compressor
won't come on.

My AC guy swapped out the start & run capacitors, bypassed the relay,
and checked all the obvious stuff. No compressor action. He theorizes
that power-line chatter at the storm's outset could have so confused
the aged system that it committed suicide trying to keep up.

His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used condensing
unit.

Observations and suggestions would be welcome.

Thanks.

When you replace your unit, make sure you
have an anti short cycle timer installed.
A newer system and most electronic thermo-
stats have this feature built in. It will
prevent the contactor in the condensing
unit from slamming on and off with power
blinks or someone playing with the temper-
ature adjustment. The timer is inexpensive
and can be added to any AC condenser. I add
timers to all the systems I install if the
feature isn't there already.

http://tinyurl.com/3h4xbe

[8~{} Uncle Monster

Most thermostats, even with that feature, won't protect against power
failure induced short-cycling because they are battery operated --
they'll just keep calling for cooling through the power chatter.

My electronic thermostat doesn't. Don't you think
the designers thought of that? All the electronic
thermostats I install have a timer that works no
matter which power source is used. I do prefer
hooking them up to run on 24 vac with the batteries
as backup. If you can tell me the brand that works
the way you say they do, please tell me so I can
avoid that brand.

[8~{} Uncle Monster

"HeyBub" wrote in message new system. The
system you have is 17 years old and you will spend a
lot for some used unit.

$750 vs. ~$1700. Just for the condensing unit.

YOu can either spend that money now or in a few years spend the money for a
new unit. Don't just get the condensing unit, but a whole new matching
system. You probably will save money on the power in the long run to make
up the differance. Just plan on spending around $ 5000 for whole new
system.

If you are planning on moving out in a few years, then it may pay you to do
just a patch job.

Uncle Monster wrote:

CJT wrote:

Uncle Monster wrote:

HeyBub wrote:

We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the
compressor won't come on.

My AC guy swapped out the start & run capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to keep
up.

His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit.

Observations and suggestions would be welcome.

Thanks.

When you replace your unit, make sure you
have an anti short cycle timer installed.
A newer system and most electronic thermo-
stats have this feature built in. It will
prevent the contactor in the condensing
unit from slamming on and off with power
blinks or someone playing with the temper-
ature adjustment. The timer is inexpensive
and can be added to any AC condenser. I add
timers to all the systems I install if the
feature isn't there already.

http://tinyurl.com/3h4xbe

[8~{} Uncle Monster


Most thermostats, even with that feature, won't protect against power
failure induced short-cycling because they are battery operated --
they'll just keep calling for cooling through the power chatter.

My electronic thermostat doesn't. Don't you think
the designers thought of that? All the electronic
thermostats I install have a timer that works no
matter which power source is used. I do prefer
hooking them up to run on 24 vac with the batteries
as backup. If you can tell me the brand that works
the way you say they do, please tell me so I can
avoid that brand.

[8~{} Uncle Monster

Honeywell

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Ken wrote:
HeyBub wrote:
Ken wrote:
HeyBub wrote:
We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the
compressor won't come on. My AC guy swapped out the start & run
capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to keep
up. His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit. Observations and suggestions would be welcome.

Thanks.


Does the fan for the condenser unit start?

No.

Your condenser unit may be different, but many have the fan motor
wired in parallel to the compressor. In other words, when power is
applied to the compressor it is also applied to the fan motor. Having
them both fail at the same time is very unlikely. Check to see if they
are wired in parallel and make sure you are getting power applied to
these units when the contactor is latched.

Did he measure the voltage at the leads going to the compressor?

Yes

And it was 220/240 volts? See above comment.

Why did he bypass the relay
(contactor)? Was it not latching up?

Even if the relay latches, the points could be burned, preventing
contact.

True, but one would only do this if there was not proper power
applied to the compressor and fan motor.




I know these are fundamental
checks, but you would be surprised at how some pros diagnose a unit.

Well, the first thing he did was test the start capacitor and
pronounced it "marginal." So he replaced it. No joy. That's when he
went through the "try this, test that" mode.

Most of the condensing units I come across
around here don't have start capacitors.
They are equipped with a dual run capacitor,
5mfd for the fan and a 30-40mfd for the
compressor. The caps have 3 terminals, one
marked "C" for common, another marked "F"
or "FAN" and another marked "H" or "HERM" for
hermetic ie compressor. When the capacitor
fails, the top pops up and the electrical
connections open. I usually replace a half
dozen failed dual capacitors a season.

http://www.myhvacparts.com/Run%20Capacitors/Capaci2.jpg

[8~{} Uncle Monster

Ralph Mowery wrote:

"CJT" wrote in message
...

Ralph Mowery wrote:


"HeyBub" wrote in message new system. The
system you have is 17 years old and you will spend a


lot for some used unit.

$750 vs. ~$1700. Just for the condensing unit.


YOu can either spend that money now or in a few years spend the money for
a new unit. Don't just get the condensing unit, but a whole new matching
system. You probably will save money on the power in the long run to
make up the differance.

That will almost certainly never happen. Do the math. If the difference
is $4k, and you spend $400/year on A/C electricity
costs, you'd have to drive those electricity costs to zero in
order to merely cover the interest on the $4K at 10%. It won't
happen.



I think in the area the airconditioner is being used it will be much more
than $ 400 a year on the AC. That is a 3 ton unit that is being installed.
Not sure what kind of heat or how much would be used in the area, but
getting a heat pump installed may be the way to go so the savings will be
for all year.

But you are sort of correct, it will take a while to pay for it.


Of course one needs to do the analysis with numbers specific to the
situation. FWIW, it costs me about $600/yr to run my four ton unit
in Austin, Texas. I was guessing the smaller unit might be cheaper.


--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

"CJT" wrote in message
...
Ralph Mowery wrote:

"HeyBub" wrote in message new system. The
system you have is 17 years old and you will spend a

lot for some used unit.

$750 vs. ~$1700. Just for the condensing unit.


YOu can either spend that money now or in a few years spend the money for
a new unit. Don't just get the condensing unit, but a whole new matching
system. You probably will save money on the power in the long run to
make up the differance.

That will almost certainly never happen. Do the math. If the difference
is $4k, and you spend $400/year on A/C electricity
costs, you'd have to drive those electricity costs to zero in
order to merely cover the interest on the $4K at 10%. It won't
happen.


I think in the area the airconditioner is being used it will be much more
than $ 400 a year on the AC. That is a 3 ton unit that is being installed.
Not sure what kind of heat or how much would be used in the area, but
getting a heat pump installed may be the way to go so the savings will be
for all year.

But you are sort of correct, it will take a while to pay for it.

CJT wrote:
Uncle Monster wrote:

CJT wrote:

Uncle Monster wrote:

HeyBub wrote:

We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the
compressor won't come on.

My AC guy swapped out the start & run capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to
keep up.

His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit.

Observations and suggestions would be welcome.

Thanks.

When you replace your unit, make sure you
have an anti short cycle timer installed.
A newer system and most electronic thermo-
stats have this feature built in. It will
prevent the contactor in the condensing
unit from slamming on and off with power
blinks or someone playing with the temper-
ature adjustment. The timer is inexpensive
and can be added to any AC condenser. I add
timers to all the systems I install if the
feature isn't there already.

http://tinyurl.com/3h4xbe

[8~{} Uncle Monster


Most thermostats, even with that feature, won't protect against power
failure induced short-cycling because they are battery operated --
they'll just keep calling for cooling through the power chatter.

My electronic thermostat doesn't. Don't you think
the designers thought of that? All the electronic
thermostats I install have a timer that works no
matter which power source is used. I do prefer
hooking them up to run on 24 vac with the batteries
as backup. If you can tell me the brand that works
the way you say they do, please tell me so I can
avoid that brand.

[8~{} Uncle Monster

Honeywell

I knew there was a reason I rarely
buy Honeywell. I use White-Rogers
80 Series with the compressor lock
out option and I never have any
problems with them.

[8~{} Uncle Monster

Stormin Mormon wrote:
Does the man own an ammeter? Very useful in such cases. Clean the
terminals on top of the compressor. Try starting it again, and check
the amp draw. Might be bad compressor, or just dirty terminals. Is
the compressor really getting 220 volts?

Yes, he had an ammeter. The compressor is drawing current, but doesn't
compress.

And to correct an earlier answer, the fan does activate and run normally -
it's just the compressor that won't go.

As an aside, I would think, in my neighborhood, there should be MANY
available used condensing units due to Ike. Heck, there are subdivisions
where the house is gone but the AC condensing unit remains, alone and
forgotten.

I see that your mechanic have check all but compressors continuity
two: start or run in this case I believe it is only run capacitor
to check compressor out does not need to be exact capacitance
it could be anything between 30 and 60 if compressor start then get
correct one and install it. at this point if compressor does not start
and if this is rotary compressor (Tecumseh, GE, Mitsubishi )
and it is drawing amperage take 5# hammer and gave it good wack
on the lower portion of casing while power is on if it does not
start by new one.
New out of Warrantee = www.coldparts.com
Tony



"HeyBub" wrote in message
news
Ken wrote:
HeyBub wrote:
We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the
compressor won't come on. My AC guy swapped out the start & run
capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to keep
up. His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit. Observations and suggestions would be welcome.

Thanks.


Does the fan for the condenser unit start?

No.

Did he measure the voltage at the leads going to the compressor?

Yes

Why did he bypass the relay
(contactor)? Was it not latching up?

Even if the relay latches, the points could be burned, preventing contact.

I know these are fundamental
checks, but you would be surprised at how some pros diagnose a unit.

Well, the first thing he did was test the start capacitor and pronounced
it "marginal." So he replaced it. No joy. That's when he went through the
"try this, test that" mode.

On Sun, 21 Sep 2008 12:19:47 -0500, "HeyBub"
wrote:

We survived Ike in extremely good shape compared to others in the vicinity.
The only significant problem is the AC unit: the compressor won't come on.

My AC guy swapped out the start & run capacitors, bypassed the relay, and
checked all the obvious stuff. No compressor action. He theorizes that
power-line chatter at the storm's outset could have so confused the aged
system that it committed suicide trying to keep up.

His best guess is a seized compressor piston on this 17-year old, 3-ton,
Trane and he's checking with his buddies for a used condensing unit.

Observations and suggestions would be welcome.

Thanks.


If your hvac guy is guessing and does not know why it won't come on
then you have the wrong ac guy. Period.

NATE Certified Heating and Air Tech wrote:
On Sun, 21 Sep 2008 12:19:47 -0500, "HeyBub"
wrote:

We survived Ike in extremely good shape compared to others in the
vicinity. The only significant problem is the AC unit: the
compressor won't come on.

My AC guy swapped out the start & run capacitors, bypassed the
relay, and checked all the obvious stuff. No compressor action. He
theorizes that power-line chatter at the storm's outset could have
so confused the aged system that it committed suicide trying to keep
up.

His best guess is a seized compressor piston on this 17-year old,
3-ton, Trane and he's checking with his buddies for a used
condensing unit.

Observations and suggestions would be welcome.

Thanks.


If your hvac guy is guessing and does not know why it won't come on
then you have the wrong ac guy. Period.

I think he used the revered Sherlock Holmes method: "If you eliminate all
other possibilities, whatever remains, no matter how improbable, must be the
answer."

On a more positive perspective, how does one determine whether the
compressor is seized?

CJT wrote:
NATE Certified Heating and Air Tech wrote:
On Tue, 23 Sep 2008 09:18:29 -0500, "HeyBub"
wrote:



On a more positive perspective, how does one determine whether the
compressor is seized?


By ohming out the windings, commont to run, common to start, run to
start and common to ground. See here for further information:
http://www.snipsmag.com/Articles/Fea...00f932a8c0____


How does an electrical resistance measurement reveal a mechanical seize-up?

Checking the electrical resistance of
the windings won't indicate a seized
compressor. It will indicate a shorted
or open winding. I also check for a short
to the metal case of the compressor. What
I look for is high current draw. If all
the electrical components are OK and I
measure a high current draw before the
internal overload opens up, that's a good
indication of a seized compressor. A three
phase compressor can be checked by switching
two of the leads to try to break it loose
by running the motor in reverse. There
are compressor analyzers available that
can reverse a single phase compressor to
break it loose if it is not severely
damaged. Here's a link to one of them:

http://tinyurl.com/3nowtq

[8~{} Uncle Monster

Uncle Monster wrote:

CJT wrote:

NATE Certified Heating and Air Tech wrote:

On Tue, 23 Sep 2008 09:18:29 -0500, "HeyBub"
wrote:



On a more positive perspective, how does one determine whether the
compressor is seized?



By ohming out the windings, commont to run, common to start, run to
start and common to ground. See here for further information:
http://www.snipsmag.com/Articles/Fea...00f932a8c0____



How does an electrical resistance measurement reveal a mechanical
seize-up?

Checking the electrical resistance of
the windings won't indicate a seized
compressor. It will indicate a shorted
or open winding.

Precisely. The other poster had it wrong.

I also check for a short
to the metal case of the compressor. What
I look for is high current draw. If all
the electrical components are OK and I
measure a high current draw before the
internal overload opens up, that's a good
indication of a seized compressor. A three
phase compressor can be checked by switching
two of the leads to try to break it loose
by running the motor in reverse. There
are compressor analyzers available that
can reverse a single phase compressor to
break it loose if it is not severely
damaged. Here's a link to one of them:

http://tinyurl.com/3nowtq

[8~{} Uncle Monster


--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .