DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   What Size Breaker Do I Need for this AC? (http://www.diychatroom.com/f18/what-size-breaker-do-i-need-ac-169583/)

opeepingtomo 01-19-2013 10:51 PM

What Size Breaker Do I Need for this AC?
 
1 Attachment(s)
https://www.dropbox.com/s/hl5cv5hvw0...2022.28.56.jpg


Thanks

jbfan 01-19-2013 11:11 PM

Max 125 amps at 240, max 100 amps at 208.
Either fuses or hacr type breaker.

Looks like you can also bring in 2 circuits at 60 or 50 amps each.

Stubbie 01-19-2013 11:23 PM

Quote:

Originally Posted by opeepingtomo (Post 1097562)

I am in agreement with JBfan however can you give a few more details ?

This looks like a used unit ?

Are you installing this to replace another unit ?

It does have the heating kit installed?

Is there any secondary ocpd at the unit?

I'm seeing a lot of wear in the left of the image you posted.

opeepingtomo 01-20-2013 12:09 AM

Moved in recently and noticed it wouldn't heat.

Had guy from work who works on AC for living take a look and only one of 3 heating elements were wired up.

He wired them up and tested the heat and I let it run for a while. After I turned heat off the breaker tripped either while turning off or when I tried to turn on later.

I had him take a look again and he said the unit was pulling 65 amps when the heater turns on.
I currently have a 60 amp breaker for the unit.

Should I put in a 70 amp breaker or is something not right here?

Stubbie 01-20-2013 12:22 AM

Quote:

Originally Posted by opeepingtomo (Post 1097585)
Moved in recently and noticed it wouldn't heat.

Had guy from work who works on AC for living take a look and only one of 3 heating elements were wired up.

He wired them up and tested the heat and I let it run for a while. After I turned heat off the breaker tripped either while turning off or when I tried to turn on later.

I had him take a look again and he said the unit was pulling 65 amps when the heater turns on.
I currently have a 60 amp breaker for the unit.

Should I put in a 70 amp breaker or is something not right here?

If he wired all heating elements up to one circuit things changed drastically considering amperage draw. The MCA for one circuit is 91.5 amps and should be on a 100 amp breaker. If things were originally wired to operate on 60 amp breaker and only one heating element you now likely have too small of wire and too small of breaker.

It would be nice to now why the unit was installed at 60 amps. Maybe your service to the home is 100 amps?

kbsparky 01-20-2013 06:09 AM

It's possible that this unit was wired with a single supply line (#6?) connected to one breaker. If each of those elements is 5kW (and I suspect that they are), then you could possibly connect 2 of them to a single 60 Amp supply using a #6 wire.

Otherwise, you will need to ensure that the wire is sufficiently large enough to handle the combined load of all 3 elements using a larger breaker.

And ensure that your service is large enough to handle the combined load.

opeepingtomo 01-20-2013 09:30 AM

Right now the house only has 100 amp service.

The unit does have #6 ran to it. The wire is a pretty short run too.

Speedy Petey 01-20-2013 09:56 AM

Quote:

Originally Posted by opeepingtomo (Post 1097701)
Right now the house only has 100 amp service.

The unit does have #6 ran to it. The wire is a pretty short run too.

You need a service upgrade to 150 or 200A and a new circuit run to the heater.
Like the others have said, you either need TWO circuits of 60 amps, or one circuit of 125A.

Someone hacked this unit into this situation.

How big is the house?
What is the BTU rating of the unit?

Speedy Petey 01-20-2013 09:58 AM

That unit is an 84 amp draw at full load.
I don't see anything that shows individual heat strips wired. Maybe it's in the instructions, but I doubt it. It should be wired all or nothing.


All times are GMT -5. The time now is 04:15 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved