Question about my AC disconnect

[Horseman1970]

Hello everyone.. i have a question that I don't know the answer to, but i'm sure people here do.

I had an ac disconnect that went out. It was an old style (square D, model number was 2q/200, i believe.) Since it went out, i went to the Home Depot, and bought a 60 amp disconnect new one, with the plug in disconnect. I installed it, turned on the outside unit, and the ac ran fine. It was a cool day, so i let it run for about a minute, then turned it off. Now that it is warmer, what is happening is this....
I turn on the outside air unit, and it runs.. for about 10-15 minutes. Then the ac breaker in my main panel trips, and it shuts off. So today, i go look at it, and now the ac breaker in my main panel automatically shuts off.
I looked closely at my ac disconnect, and you can see where an arc occured between the copper blades and the spaces they plug in to.
What would be causing this? As you can tell, I am not an electrician and do not know what is causing this?
Any help you guys can provide would be greatly appreciated.

Thank you.

 

[Dennis Alwon]

I am allowing this thread but lets keep it to an explanation of what is wrong not a how to thread

 

[Horseman1970]

Thanks Dennis. That is what i am asking.. any ideas on what is wrong? I can research how to fix it..

 

[just the cowboy]

Did you open it under load

Did you open it under load

Did you open or close the disconnect under a heavy load like when it was starting? The arc might of came from that, and it might of tripped the breaker. Why did the old one fail?

 

[growler]

I turn on the outside air unit, and it runs.. for about 10-15 minutes. Then the ac breaker in my main panel trips, and it shuts off. So today, i go look at it, and now the ac breaker in my main panel automatically shuts off.
I looked closely at my ac disconnect, and you can see where an arc occured between the copper blades and the spaces they plug in to.
What would be causing this? As you can tell, I am not an electrician and do not know what is causing this?
Any help you guys can provide would be greatly appreciated.

Thank you.

What size breaker is listed as max breaker size on the AC compressor (name plate)? What size breaker is in the main panel? Make sure you have correct breakers.

When you installed new disconnect did you make sure to hook line to line terminals and load to load terminals? Did you insert that jumper bar correctly and tightly?

 

[mwm1752]

Hello everyone.. i have a question that I don't know the answer to, but i'm sure people here do.

I had an ac disconnect that went out. It was an old style (square D, model number was 2q/200, i believe.) Since it went out, i went to the Home Depot, and bought a 60 amp disconnect new one, with the plug in disconnect. I installed it, turned on the outside unit, and the ac ran fine. It was a cool day, so i let it run for about a minute, then turned it off. Now that it is warmer, what is happening is this....
I turn on the outside air unit, and it runs.. for about 10-15 minutes. Then the ac breaker in my main panel trips, and it shuts off. So today, i go look at it, and now the ac breaker in my main panel automatically shuts off.
I looked closely at my ac disconnect, and you can see where an arc occured between the copper blades and the spaces they plug in to.
What would be causing this? As you can tell, I am not an electrician and do not know what is causing this?
Any help you guys can provide would be greatly appreciated.

Thank you.

So many questions, I would recommend you get a professional to troubleshoot - you can buy unneccesary parts spend lots of money and still not figure it out. Not saying you can't do it - it may be easier & less costly to hire someone. Giving advice blindly is not a good idea. sounds like an appliance issue.

 

[Jraef]

Here's my assessment of what went wrong...

You had a problem with an AC unit.
You looked and saw a damaged disconnect.
You ASSumed the problem was the damaged disconnect, so you replaced it.
The problem was NOT the damaged disconnect, the problem DAMAGED the disconnect. Now the problem has damaged something else.

What a good electrician does is to not ASSume that a damaged protective device IS the problem, it is a SYMPTOM of a problem that needs further investigation.

So is it a bad AC unit? Maybe, or a bad wire, or something else that a good troubleshooter with eyes on the installation and the proper test instruments can get to the bottom of. I don't think anyone can help you any more than that from here.