Sorry for the caps in title. Just want to be clear, the contacter circuit is closed (not engaged/off position) and the AC condensing unit is constantly on as soon as power is supplied.

AC flipped the circuit breaker a few days ago. Troubleshooting:
1. Changed the Capacitor
2. Changed the Contacter
3. Reset all breakers
4. Checked all voltage - 240v, 120v (poles), 24v - all is good.

When I turned on main breaker to the outside condensing unit, the fan started immediately and the compressor attempted to start. The contacter is not engaged. The Thermostat is OFF.

While it is on, the compressor never kicks on.

I have checked the wiring schematics so many times I will remember them in 50 years

I even put the old contacter back on (after testing - appears good). Wired exact way as photos taken before removal. Same issue.

Important - if I manually push the contactor, I hear the system short (pop) and the circuit breaker trips. Once I flip breaker back on, fan starts again.

Guessing a short - but odd. No chewing vermin in my area, so signs of frayed wires - some spider webs, etc.

Any thoughts or next steps are appreciated. I have searched all resources and have not seen this problem.

 

It sounds like you have a shorted compressor or fan motor and you have a single pole contactor.

The fan motor has 3 wires if it is an OEM or 4 wires if it has been replaced with a universal motor ( or a 2 speed which is less common)

Does the problem persist if you completely unwire the fan motor?

What is the make and complete model number of this condenser? We may be able to bring up a diagram for a Carrier, Trane or Lennox.

 

Condenser Unit: Goodman GSC 14 Seer GSC140361AA/AB

I have the Goodman Diagram - shows fan motor is:
0131M00014PS MOTOR, 1/4 HP, 1 SP, 8 PL

If I unwire the fan motor, wont it shut off regardless if problem persists
Of course - I can do this tomorrow early. Once unwired, what is next step beside replacing the motor? Any possibility of fixing short or rewiring, or is it just easier to replace?

Question: How is the fan receiving power at all if the contacter is not engaged. Based on limited knowledge of electrical wiring, I would think that no power = no power. What am I missing?

Also, if compressor, should I simply replace the whole condenser? I am already into it for $150 after a new motor and a new unit only costs $950 assuming I can match to internal unit and hook it up myself.

Never opposed to calling a pro when needed...a man must know his limitations! But love the satisfaction of learning and fixing things myself.

 

Does the compressor still act up when the fan is disconnected? If not then the problem would point to the fan.

Replace the fan motor if it proves to be the problem.

The condenser has two 120 volt legs of power. If you have a short to ground and the contactor only breaks one leg then you have a circuit with half of the required power. It would not run at full speed but...

If you need a compressor and it is not under warranty then I recommend a whole new condenser. A would also recommend calling a pro to install it.

 

Hi, what happened that caused you to change the Cap and contactor ?
Geo

 

Original Issue - a secondary circuit breaker flipped. Unfortunately I forgot this breaker box existed (in the closet where the furnace was before remodel).

I had no power. I had a new Capacitor and contactor (backups) so I installed before testing anything.

Since I still did not have power, I started tracing romex and found the 2nd box. flipped the breaker on and installed the 240v breaker at the AC (pull type).

The Thermastat was off completely, but the fan started immediately and the compressor kept trying to kick on - however, the attempts to start were weak - sounded around 30-50% power compared to normal; more of loud intermittant buzzes.

The contactor was NOT engaged. When I manually push/engage the contractor the breaker flips again.

Could something be miswired and just happen to work for the past 9 years? (wiring 100% mirrors pre-install of new cap and contactor).

I will give a last ditch effort to check the fan wiring today - not hopeful since I have not seen this issue on this forum or on the 100+ you tube videos.

Question: Is there an easy way to disconnect fan wiring from the control panel (e.g. at capacitor) or do I need to open the unit?

 

No need to open the unit.

 

Last ditch effort ??

It's not a last ditch effort.... condensor fans short all the time.
I've seen that same exact problem several times.

 

update (not really) - 3 wire fan motor - I disconnected the brown wire from capacitor Fan, black from contactor, and purple from capacitor common.

Turned power on, no response from compressor. Manually pushed contactor - no response; Thermastat On - no response.

Hooked fan back up, fan spins. No attempts by the compressor to start anymore. Guessing I shorted that yesterday by manually depressing the contractor with a short elsewhere.

Any suggestions on next steps?

 

The fan was spinning with the contactor open..... not energized ?

Did you have a volt/ohmmeter ?

You're going to need to check continuity on the fan motor windings as well as the compressor.
Continuity also needs to be checked from the three fan motor wires and the three compressor lines to ground. There should be no continuity measured.


Post 11 describes compressor checking.
http://www.doityourself.com/forum/ai...t-working.html

 

Fan spins with the contactor open. Compressor tried to come on as well (not anymore).

Tested Fan and compressor -
Fan
Prpl to Brn 88
Blk to Prpl 28
Blk to Brn 60
Brn / Prpl / Blk to Equipment Ground (in control panel) = No reading / No continuity

Compressor
Yellow to Red = Continuity
Black to Yellow or Red = Nothing; no reading; like two separate circuits.
Black to Ground = No Reading
Yellow or Red to Equipment Ground (in control panel) = Continuity

Note on wiring -
Fan: Brown - Capacitor Fan; Purple - Capacitor Common; Black - Contactor
Compressor: Red - Contactor (T2 switch side); Black - Contactor (T1); Yellow - Capacitor Herm

Next steps or interpretation would be greatly appreciated. Thanks.

 

Those readings tell me your compressor is bad.

 

Thats what I thought. Is there any hope?

 

I'm assuming you disconnected the wiring for the compressor.

Any compressor wire that shows continuity to ground is a shorted motor winding signifying a defective compressor.

The compressor will need replacement.

 

No. I did not discounnect wiring from compressor.

Tested everything from the control panel. Have not removed the top/fan or opened the unit. All wiring is single run with no splices, goes directly to compressor. Tested ends that connect to contactor and capacitor.

Did I not test correctly?

 

As a 100% confirmation we try to test directly at the compressor when we find an open to eliminate a burned connection at the compressor.

Although usually when a short is detected.... it's pretty conclusive unless the black wire got cut and is hitting ground.

 

Thank you all for the assistance.

Jim

 

I am fairly sure I need a new compressor. Having a someone come out to give me a second opinion tomorrow.

I have a:
Goodman GSC 14 SEER
140361AB

This unit takes R22 refrigerant.

I have found the compressor at several vendors for $600-800.

I would prefer to simply change out the compressor since the unit is only 12 years old and several components have already been changed out. Furthermore, the inside unit was placed in my attic before the dry wall on the ceiling was completed (seriously?). Meaning I have to rip out part of the ceiling to swap units. Not to mention the $5k + price tag, vs

 

Rather than start a new thread.....

An entire condensor unit could be precharged. A compressor cannot be as it needs to be connected to the lines in the old condensor.

There are too many variables to quote prices. The only way to know for sure if you're being treated fairly is to get several estimates.

R-22 refrigerant can be very expensive.
It must be evacuated from the system and it should be able to be reused.
It may have to be cleaned first if the compressor appears to have internally self destructed. That's a judgement call by the tech.

 

I just went in the attic (air hadler/coils) and discovered that both r22 and r410A are suitable.

If I replace the whole condensing unit (r22 to 410a), what else would be needed? based on limited research...

1. Vaccuum pump mineral oil from the lines.
2. Install pre-charged 410A Condensing Unit.

Done (ha ha ha).

Of course testing and such...

Problem - my Uncle is an HVAC supply guy on the other coast. He can get me parts or whole unit at wholesale. But no local tech wants to do work without selling me the parts.

Called some small guys. Waiting for call backs.

Wondering if I could tackle the job on my own (with some new tools/guages, etc). Thoughts?

 

As per the directions of the DIY administrators we cannot discuss charging procedures.
There are sites were there is open discussion in regards to those questions.

http://www.doityourself.com/forum/ai...ng-your-c.html