A/C Air Handler with Heat Circuit Breaker

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Old 02-08-09, 03:30 PM
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A/C Air Handler with Heat Circuit Breaker

We had a new 2 Ton A/C installed. The air handler is in the attic. My understanding is that there is a 10 KW electric heating element in it that was installed at the install time. This air handler is fed by a 60 amp breaker in the main panel to about a 100' run of #6AWG cable to a disconect (non-fused) and then directly into the air handler. There is NO circuit breaker on the air handler. From the documentation, it appears that there should have been a circuit breaker installed when the heating element was installed/added. The blower motor in the air handler appears to be a 1/3HP DC motor. Does anyone know the code requirements or common sense for the requirement of a circuit breaker on this piece of equipment?
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Old 02-08-09, 03:35 PM
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Depending on the manufacturer, they usually come already mounted in the unit. There may be a cover over it with one 5/16 head screw.
As far as the overcurrent and short circuit protectoion, that is done at the panel with the 60 amp breaker.

Anything at the unit is just a means of disconnect.
 
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Old 02-08-09, 03:48 PM
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There is just a blank cover where the breaker would go. We also have a 3 Ton unit on the other side of the house. That one has a 50 amp breaker on the air handler. i remember the installer saying that it was not needed on the 2 Ton but i do not remember the reason.
 
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Old 02-08-09, 03:52 PM
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There shouldand needs to be a disconnect at the unit, not necessarily a "breaker" The "breaker" on the other unit is just a means of disconnect.

Just a pull out disconnect, like those on the condensing units will suffice. Also, not sure if this is a walk up attic but there needs to be a light at the unit and a GFI receptacle within 25' and the same level.
 
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Old 02-08-09, 04:14 PM
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There is a 50 Amp disconnect box about 4 feet from the unit. There is also a light but no GFI. There is an outlet on the porcelain light fixture. The attic only has access using a 6' step ladder thru an access hatch. It is also strange that there is a 60 amp breaker in the main panel, not a 50 amp. The feed is a #6AWG.
 
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Old 02-08-09, 04:20 PM
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You can look on the unit nameplate and it will have various heat packages, they are supposed to mark the heat package they installed and it will list the minimum ckt ampacity and the max ocpd.

You say 50 amp box, does it have a 50 amp breaker in it? Disconnects only come in 30, 60, 100 and so on.

50 amps may be the minimum and 55 maybe the max but if your panel manufacturer doesn't make a 55 then thy're allowed to go to 60.
 
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Old 02-08-09, 04:36 PM
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I take back the GFI requirement in the attic.
 
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Old 02-08-09, 06:02 PM
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The disconnect box does not have a breaker or fuses. It is just a metal bar that makes or breaks the circuit.
 
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Old 02-08-09, 06:14 PM
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That's all that is needed. The breaker in the panel protects the circuit.
 
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Old 02-08-09, 06:33 PM
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What do you need heat for in South Florida anyway?...lol Seems like you'd be running some a/c about now Beer 4U2
 
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Old 02-08-09, 06:38 PM
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The beginning of this week saw some 36 degree temps in the morning, kind of unusual but it happens every few years. That is how I noticed the missing breaker. Remember, the other air handler on the other side of the house has a breaker on the unit. The units are identicle, except for the breaker. What i find troubling is that there is a 60 amp breaker in the panel feeding a #6 AWG. I thought that #6 AWG was rated to require a 50 amp breaker by the NEC.
 
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Old 02-08-09, 08:13 PM
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For 50 amp breaker it may be ok for most case but all it boil down to the type of conductor it use that will affect the whole performace and OCPD requirement.

Senice you are in Florida I am pretty sure you are still on 2005 code and should be taking in 2008 NEC code cycle anytime { I do not know when that will be effect for that state.}

If it was SE { Service Entrance } Cable if in copper verison yeah 60 amp will work but alum verison no., it have to use 50 amp breaker but a nice gotcha if you are allready on 08 Code that will change a bit.

If that was in the conduit the THHN/THWN conductors can be rated at 75C compared to the SE or NM's they have to be on 60C rating

Merci,Marc
 
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Old 02-09-09, 09:43 PM
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Florida has adopted the 2008 NEC without exceptions.
Scheduled to go into effect July 1, 2009.
 
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Old 02-09-09, 09:46 PM
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Originally Posted by dezwit View Post
Florida has adopted the 2008 NEC without exceptions.
Scheduled to go into effect July 1, 2009.
Merci ( Thanks)
For get the info verified I knew it will be updated but not know when but again thanks so I know when they are in effect.

Merci,Marc
 
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Old 02-10-09, 07:48 AM
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It's all copper. The Air Conditioning company is coming back and installing a 50 Amp breaker in the air handler so it is exactly like the other one. It's nice working with a responsive company.
 
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