Help with A/C issue not working.

[Rand]

Background:
Woke up this morning at 2am to 75f in the house and it was set for 73.
Checked the thermostat and it said it was running for 13 hours yesterday typical is 4 hours.
checked outside no activity.

Went to work, returned home.

Checked breaker. it was popped.
reset breaker and went outside.
turning on AC (from phone app) resulted in a popping noise after .5s and breaker was also popped again.

Attempted diagnostics.
The cap appeared to not be functional. I used a meter on it but the meter is confusing chinese poo brand. not 100% sure it was on right setting.

Replaced the capacitor.. 13.50 at granger.
Cycled the A/C on while standing outside.
now the breaker doesnt pop
but nothing happens outside either. very faint humming probably the contactor.
I did triple check the wires are on right HERM, C and Fan and they were never incorrectly connected.

What's my next step?
Edit:
Additonal info
Carrier A/C Age aprox 11 years.

I am not opposed to calling a pro... but want to try any easy stuff first.. before forking out the 500$ if its 50 in parts.

 

[Dave Sherman]

Maybe check to make sure there's no cartridge fuse that blew in the outside disconnect box? The contactor is energized by 24 volts AC from the thermostat, so if that's humming but no fan running and not even a hum from the compressor, then you're still missing 240 VAC somewhere. Make sure the contactor is clicking when it turns on, and see if you have 240 VAC going to the compressor and fan. If it's not clicking and no voltage is present when it's closed, then the contactor may be suspect. You did replace the capacitor with one with the same capacitance and voltage rating, yes?

 

[Rand]

yes same specs although its a slightly fatter model so I Had to mod the bracket a little.
35/5 370volt

the contactor does the click on and off but no power is consumed.

I have a contactor on order for saturday. 22$ They had them local but 80$

 

[CDX825]

Like Dave said check and see if you are getting 240 volts to the contactor.

 

[Rand]

Like Dave said check and see if you are getting 240 volts to the contactor.

Just started storming I will continue in a few days.

 

[Cujet]

Just an FYI for absolute emergencies. If the condensor fan fails, and the compressor is still operational, one can often use a shop fan on top, blowing up, and a series of wet towels to seal the airflow. If your fan is not enough, spray some water on the coils. It will work.

 

[zzyzzx]

Just started storming I will continue in a few days.

That's when you break out the beach umbrella to keep the rain off you while you work on the outside AC parts.

 

[nomas]

Check the contacts to see if they are burnt . I had to burnish the contacts on one of my units years ago because they were kind of crispy looking .

 

[Touring5]

If neither the fan or compressor start, it suggests that the problem is at or before the contactor. (assuming cap is good and wired correctly)

If one runs and the other doesn't check for burn wire or bad connections.

Last year I had a situation with a 30+ yo Heil where the fan ran, the compressor didn't, and both the contactor and cap were good. Wires to the compressor looked fine. As a last ditch effort I removed the cover on the compressor terminals an discovered a corroded flag terminal with the wire off. Re-terminated the 3 wires and it was back in service.

 

[alarmguy]

just my own thoughts is a homeowner, I am not in anyway an expert other than changing my own condenser fans, capacitors and contactors and Refilling Freon.

If it was me, I would be concerned why the circuit breaker tripped. If a compressor fails typically it will cycle on and off meaning a thermal cutout sensor.
I know the breaker doesnt trip since you replaced the capacitor but I cant help but think the capacitor was just a victim of what is going on.
I think either a wiring short or the compressor is shot. Takes a lot of trip a breaker and why I think the compressor or less likely an outright short someplace to trip that breaker. It's interesting hope you keep us updated. Im really thinking, again, as a homeowner, I would be praying its not the compressor because that is where my mind goes.

 

[Rand]

Ok so I ohm'd the compressor terminals
r&c1.4 s&r 3.0 c&s 1.7

Seems low?
I figured out the other stuff it was because I was tired . The fuses did indeed blow the second time.
No shorts to ground.

Copeland scroll compressor ...from memory.

 

[Skippy722]

The hum makes me think it’s not getting the right voltage. Had a storm roll through at work once and we lost a phase, the exhaust fans for the shop made a humming noise when the power came back on.

 

[Rand]

The hum makes me think it’s not getting the right voltage. Had a storm roll through at work once and we lost a phase, the exhaust fans for the shop made a humming noise when the power came back on.

very low humming noise probably the contactor.

I have a new contactor arriving tomorrow supposedly carrier oem brand for 18$
after that I'll hook it up with just the fan and see if it pops the breaker. if the fan runs
I'll hook up just the compressor. I might also dive into the wiring a little harder to see if there is a chafed or chewed spot.(nothing was apparent in a quick inspection.. but some sections of the wires are harder to get at.
I have 2 legs of 120 on the fuse/disconnect for 247 volts earlier today.

Contactor appears to function but its old and crusty so 18$ is nothing I suppose.

 

[brianl703]

I might also dive into the wiring a little harder to see if there is a chafed or chewed spot.

Measure the resistance across the two terminals on the LOAD side of the contactor, and from each of those two terminals to ground. That will tell you if you have a short somewhere.

 

[Nick1994]

Stick a screwdriver in and see if the fan spins easily. Might be a bad fan motor.

 

[97prizm]

Background:
Woke up this morning at 2am to 75f in the house and it was set for 73.
Checked the thermostat and it said it was running for 13 hours yesterday typical is 4 hours.
checked outside no activity.

Went to work, returned home.

Checked breaker. it was popped.
reset breaker and went outside.
turning on AC (from phone app) resulted in a popping noise after .5s and breaker was also popped again.

Attempted diagnostics.
The cap appeared to not be functional. I used a meter on it but the meter is confusing chinese poo brand. not 100% sure it was on right setting.

Replaced the capacitor.. 13.50 at granger.
Cycled the A/C on while standing outside.
now the breaker doesnt pop
but nothing happens outside either. very faint humming probably the contactor.
I did triple check the wires are on right HERM, C and Fan and they were never incorrectly connected.

What's my next step?
Edit:
Additonal info
Carrier A/C Age aprox 11 years.

I am not opposed to calling a pro... but want to try any easy stuff first.. before forking out the 500$ if its 50 in parts.
View attachment 181911

Also check the batteries in the thermostat. I've had bad batteries cause the unit to act irrationally.

 

[Rand]

Also check the batteries in the thermostat. I've had bad batteries cause the unit to act irrationally.

pop breakers? I have a nest it is hardwired.

Stick a screwdriver in and see if the fan spins easily. Might be a bad fan motor.

Did that spins fine.

Measure the resistance across the two terminals on the LOAD side of the contactor, and from each of those two terminals to ground. That will tell you if you have a short somewhere.

I think I did that but for clarification here is a pic which ones are you talking about specifically.
There were no shorts to ground.

 

[brianl703]

I colored the load side terminals orange.. measure across these and then measure from each of these to ground.

 

[Nukeman7]

That contactor looks gnarly and may be on the way out. Did you manually engage the contactor with an insulated screwdriver or a non-conductive stick? If not, try pushing in the (spring loaded) black plastic rectangular plunger shown in the photo below to engage the electrical contacts for the fan and compressor.

If everything runs, the 24 volt side of the contactor relay is not operating correctly, either due to lack of voltage or an open magnetic coil.

---

 

[brianl703]

I think I did that but for clarification here is a pic which ones are you talking about specifically.
There were no shorts to ground.

Testing between the terminals on the LOAD side and from those terminals to ground will tell you if there's a short between those connections anywhere in the unit--fan motor, wiring, etc.

If there is, you'll have to start disconnecting wires to narrow it down.

There's also the possibility that you have an intermittent short, wire has rubbed through and only shorts out to ground sometimes. You'll need to do a visual inspection to find this.