View Full Version : A/C Service Disconnect
Chris Skoczylas
08-22-2007, 07:41 AM
The A/C condensing coil unit is installed outside next to the main electricl panel and does not have a separate service disconect. Does the breaker in the main panel meet the service disconect requirement?
Brian E Kelly
08-22-2007, 08:11 AM
No the unit should have a separate shut off. At least in my neck of the woods. The disconnect mounted be the unit is used for the service tech when he or she is working on the unit.
Richard Rushing
08-22-2007, 11:59 AM
IRC
Table 4001.5:
(Under)Air-conditioning condensing units and heat pumps units---(under-Allowable disconnecting means) A readily accessible disconnect within sight of the unit as the only allowable means (with a sub-note (a) ).
Sub Note (a): The disconnecting means shall be permitted to be installed on or within the unit. It shall not be located on panels designed to allow access to the unit.
Richard Rushing
08-22-2007, 12:10 PM
Here is the attachment from previous post...
Jerry Peck
08-22-2007, 12:32 PM
If the disconnect for the condenser unit is in the electrical service equipment/panel next to/near the condenser unit, then, no, it does not require a separate disconnect at the unit.
Installing a disconnect "on" the a/c unit, condenser unit or air handler unit, is virtually a no-no as the disconnect 'is not allowed' to be on a panel which is removable for service, repair, etc.
When speaking of residential a/c units, there are few, if any, 'non-removable panels' which cannot be removed to allow for service, repair, etc.
When speaking of large commercial units, yeah, there are typically large areas which have fixed in place panels and on which the disconnect 'is allowed to be' mounted, however, most of those guys know that they do not want to work on/replace a unit which has a disconnect on it, so the disconnect is almost always mounted nearby.
Breakers located elsewhere (not near the unit) are not allowed to be used as the disconnect, not even when there is a breaker lock-out device installed (with one exception, which only applies to industrial processes in which the equipment is a necessary part of that industrial process).
Brian E Kelly
08-22-2007, 01:01 PM
My local Electric company does not allow the disconnect in any panel. It has to be with in reach of the condensing unit. Any every electric company may be different.
Jerry Peck
08-22-2007, 01:15 PM
My local Electric company does not allow the disconnect in any panel. It has to be with in reach of the condensing unit. Any every electric company may be different.
Why does your "Electric company" have anything to do with what goes on past the meter, or especially past the service equipment?
Their rules and regulations stop at the owner owned portion, which is typically (overhead service) at their splice to the service entrance conductors at the over head service drop, or, for underground service, where the service laterals land on the meter can.
I'm confused. Please explain.
Richard Rushing
08-22-2007, 01:22 PM
Agreed. The electric service company has no say with what goes on after their equipment. Otherwise, they would have more employees than General Motors.
As my post stated before, the service equipment disconnect can be in the service panel mounted on the exterior of the home-- within sight.
rr
Brian E Kelly
08-22-2007, 01:26 PM
The electric company does have a say as to what goes past the meter. At least around here, as does the gas company have a say as to what goes in after the meter. The electric company also has say in underground wiring after the meter also.
Richard Rushing
08-22-2007, 01:42 PM
I've given you the code (per the IRC). Whether anything is used or not well... it's up to you to believe what the code says or not.
The electrical company's equipment stops at the meter. After the meter is the main/service equipment/ disconnect. If that is on the exterior wall in the vicinity of the condensing unit-- NO PROBLEM.
The unit does not require ANOTHER/SEPARATE disconnect-- Unless your AHJ has upgraded the requirement per the city/ county electrical standards.
Brian E Kelly
08-24-2007, 06:39 AM
What the code says or does not say is not the issue here as local code supersedes all other codes, and the electric company states, there must be an independent disconnect for all condensing units along with air handler/furnaces.
Richard Rushing
08-24-2007, 08:03 AM
Brian, could you post a copy of that requiremet by the electric compnay?
Brian E Kelly
08-24-2007, 09:12 AM
To tell the truth I have never seen this in writing but when we have a new house or anytime were the electric co. is there to inspect or turn on power they check it out. I have been scolded one time as the disconnect was farther away than 6' from the unit and they made me move it closer. My tech was lazy and it was easier for him to install the disconnect there rather than where it should be. I will try and get this from them but as it will not be that fast coming.
George E Clower
08-24-2007, 11:54 AM
The A/C condensing coil unit is installed outside next to the main electricl panel and does not have a separate service disconect. Does the breaker in the main panel meet the service disconect requirement?
The National Electric Code does not require a separate disconnect switch when a breaker panel is within sight of the condensing unit and not otherwise more than 50 feet from the unit; however, some jurisdictions are more restrictive than the NEC. In my city, Corpus Christi, Texas, the city has revised NEC Section 440.11 to read as follows:
"440.11 General.
"(A) Purpose. The provisions of Part B are intended to require disconnecting means capable of disconnecting air-conditioning and refrigeration equipment, including motor-compressors and controllers from the circuit conductions.
"(B) Branch Circuits. A disconnecting means must be provided in the ungrounded conductors of each branch circuit to electrically operated air conditioning components.
"(C) Fusible Disconnect. A fusible disconnect switch must be installed for single phase air conditioning equipment of five tons rating or less.
"(D) Integrally install components. Disconnecting means must not be required on equipment with integrally installed disconnecting means."
And the initial paragraph of NEC Section 440.14 is revised to read as follows:
"440.14. Location. Disconnecting means shall be locatd within sight from, readily accessible from, and within six feet of the air-conditioning or refrigeration equipment. The disconnecting means shall be permitted to be installed on or within the air-conditioning or refrigeration equipment."
As regards the latter permitted location, I would recommend not installing a disconnect on the unit that was not intergral with the unit since most panels on a condensing unit are capable of be removed for maintenance. Also the requirement for a fused-type disconnect switch seems like an overkill for a residential unit, but that's what my city requires. These installations are inspected by the city electrical inspector and not the power company.
George E. Clower, AIA
Architect
Jerry Peck
08-24-2007, 12:12 PM
however, some jurisdictions are more restrictive than the NEC. In my city, Corpus Christi, Texas, the city has revised NEC Section 440.11 to read as follows:
George,
Actually, the city of Corpus Christi cannot "revise the NEC", it can only adopted a its own electrical code "based on" the NEC "with revisions".
Just wording, but it could make a difference.
Thom Walker
08-24-2007, 09:02 PM
Hi George,
Good to see you here again. I was looking this up as you posted.
I will take exception with your overkill opinion. I got the same argument from an HVAc tech on site. I happened to be near when he got a phone call, left the area of the condensing unit to talk, and I flipped the breaker back on (then off again). When he came back, he walked straight back to the unit and started to work. I told him to stop working because dead guys aren't allowed to service AC's. I explained what I had done.
Anything can and does happen on a job site. A fusible disconnect is as foolproof as you can get. Breakers are mechanical items. Sometimes they fail. Or they can be reset without the knowledge of the worker they are supposed to be protecting.
DO NOT LET THIS GET AROUND, but occassionally the guys in our City do the right thing. This requirement is one of them.
Jerry Peck
08-25-2007, 09:19 AM
Thom, George,
Question for you guys.
Why not a non-fused pull out?
By the way, *very few* (if any) of those "breakers" you see being used in a "disconnect" for a/c and other uses are actually "breakers" - most, if not all, will be molded case switches. They are identical to breakers in that they use the same plastic casing, however, inside is only a switching device, no overcurrent protection.
The *REAL* (and I mean "real") disadvantage to fused disconnects is that, and we have all seen this, the fuses are removed and replaced with short pieces of copper pipe.
Install a non-fused pull out. The best service disconnect protection you can get (I've seem many HVAC techs put the pullouts in their tool carriers - that way, no one can come by and put it back in without them knowing it).
Thom Walker
08-25-2007, 10:47 AM
Or non fused pull out. You are correct and I should have included that, as around here they are far more common than are fusible. The point is I would not depend on a breaker or the carlssness of someone else where my electrical safety was concerned.
Re: using a piece of copper, a real CMI, (Certified Master Idiot) will figure a way to over ride any safety device. This is not a slam to NACHI folks. They happen to have the same initials. :D
Aaron Miller
08-27-2007, 12:48 AM
George,
Actually, the city of Corpus Christi cannot "revise the NEC", it can only adopted a its own electrical code "based on" the NEC "with revisions".
Just wording, but it could make a difference.
Jerry,
I think he meant "amended" and not "revised". And yes, they can pass into official city ordinance a list of ammendments to any model code.
But, of course, you knew that, right?
Aaron
Jerry Peck
08-27-2007, 11:19 AM
I think he meant "amended" and not "revised". And yes, they can pass into official city ordinance a list of ammendments to any model code.
You may pass "amendments" to a model code, however you cannot "revise" the model code. You are correct there, if that what was meant.
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