Ac condensers disconnect

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jkrauss

Member
I have a small commercial job the building has a 100 amp service 120/208 volt single phase building is only 950 sq feet stick built construction . My ? Is there is a existing ac condenser the feed is fed from the load side of the meter with a 30 amp fuseable disconnect serving the equipment is this code compliant . The ac disconnect is les then three feet from meter .
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
Most likely not.
Where is the other service disconnect?
You can have more than one disconnect but they should be in one location.
How are the additional set of wires made up under the meter lugs?
Meter terminals are setup for only one conductor until you get to the 320 amp size.
Is the disconnect suitable for use as service equipment?
How is the GEC installed or is it?
 

jkrauss

Member
Most likely not.
Where is the other service disconnect?
You can have more than one disconnect but they should be in one location.
How are the additional set of wires made up under the meter lugs?
Meter terminals are setup for only one conductor until you get to the 320 amp size.
Is the disconnect suitable for use as service equipment?
How is the GEC installed or is it?

The main panel is on the back side of the wall the ac disconnect is on .And it is a 100 amp meter there was a exception in the code for main not being grouped for ac units but I can't find it in the code book I have seen 100 amp meter's taped twice for interpreting water heaters. There is no Gec but I could run one .
 

jkrauss

Member
I see a lot of things, but that doesn't mean they are correct.

Why are you touching this installation? Once you do, your name is on it.

This is a remodel it,s is going to be a hair salon this is the only possible code violation I can see in the building.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I'm in agreement with ptonsparky.
Service disconnects must be grouped (I know of no "AC exception" that you mentioned)
Most likely the meter was not listed for the two wire-one lug arrangement.
 

jstjohnz

Member
I'm in agreement with ptonsparky.
Service disconnects must be grouped (I know of no "AC exception" that you mentioned)
Most likely the meter was not listed for the two wire-one lug arrangement.

The A/C disconnect and wiring to it is all outside of the structure. I don't think it has to be grouped with disconnects for service to the inside of the structure.
 

jumper

Senior Member
The A/C disconnect and wiring to it is all outside of the structure. I don't think it has to be grouped with disconnects for service to the inside of the structure.

OP said:

I have a small commercial job the building has a 100 amp service 120/208 volt single phase building is only 950 sq feet stick built construction . My ? Is there is a existing ac condenser the feed is fed from the load side of the meter with a 30 amp fuseable disconnect serving the equipment is this code compliant . The ac disconnect is les then three feet from meter .

So yes, it would need to grouped with the other disconnects.
 

jstjohnz

Member
I'm not understanding the significance of the bold text in your post. You've got a meter with 2 sets of SE conductors on the load side. One set feeds a service disconnect on a panel inside the building. The other set feeds a service disconnect on the outside of the building which powers an A/C condenser that is also outside the building.

My point is that since no part of the A/C service enters the building, why would its disconnect have to be grouped with the building service disconnect?

For example, what if the 2nd set of SE conductors on the load side of the meter fed a separate structure? Would the disconnect for the separate structure need to be adjacent to the disconnect for the main building?
 

jumper

Senior Member
I'm not understanding the significance of the bold text in your post. You've got a meter with 2 sets of SE conductors on the load side. One set feeds a service disconnect on a panel inside the building. The other set feeds a service disconnect on the outside of the building which powers an A/C condenser that is also outside the building.

My point is that since no part of the A/C service enters the building, why would its disconnect have to be grouped with the building service disconnect?

For example, what if the 2nd set of SE conductors on the load side of the meter fed a separate structure? Would the disconnect for the separate structure need to be adjacent to the disconnect for the main building?

For the separate structure, no. Can the same reasoning be applied to the AC......hmmm.

Interesting proposition. While 230.71 talks about grouping the disconnects, 230.70 does say this:

230.70 General. Means shall be provided to disconnect all
conductors in a building or other structure from the service entrance
conductors.

The AC conductors are not in the building....

I can honestly say you have given me pause to think about it.
 

iwire

Moderator
Staff member
Location
Massachusetts
Interesting proposition. While 230.71 talks about grouping the disconnects, 230.70 does say this:



The AC conductors are not in the building....

I can honestly say you have given me pause to think about it.

I think you are going down the wrong path.

230.74 Simultaneous Opening of Poles. Each service disconnect
shall simultaneously disconnect all ungrounded
service conductors that it controls from the premises wiring
system.

The HVAC circuit is part of the premises wiring system.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
The HVAC circuit is part of the premises wiring system.
But the HVAC service disconnect does disconnect the service conductors it controls from the premises wiring system. Where's the 230.74 violation?

Just call the HVAC unit an accessory structure, which is permitted its own set of service conductors under 230.40 Exception No. 3, install the grounding electrode system required under 250.24(A), and the service disconnects no longer need to be grouped under 230.72.

Cheers, Wayne
 

iwire

Moderator
Staff member
Location
Massachusetts
But the HVAC service disconnect does disconnect the service conductors it controls from the premises wiring system. Where's the 230.74 violation?

I don't know that there is any violtion, I was just using 230.74 to point out to Dereck that the service disconect must disconect all the power not just things inside the building.
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
But the HVAC service disconnect does disconnect the service conductors it contrIs from the premises wiring system. Where's the 230.74 violation?

Just call the HVAC unit an accessory structure, which is permitted its own set of service conductors under 230.40 Exception No. 3, install the grounding electrode system required under 250.24(A), and the service disconnects no longer need to be grouped under 230.72.

Cheers, Wayne
That still leaves the problem at the meter lugs.
I would think the SE for your accessory structure should be on the structure, not another. IDK because I've never had the b****s to test that scenario.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
It probably a mistake to even consider "intent", but I can see a difference between a 2nd disconnect on a separate structure and a 2nd one of the same structure. It seems the reasoning for "grouping" has been to enable folks needing to turn off power to go to one place to do so.
If it is allowed, then the 230.2(E) required marking should be addressed.
 

kwired

Electron manager
Location
NE Nebraska
The A/C disconnect and wiring to it is all outside of the structure. I don't think it has to be grouped with disconnects for service to the inside of the structure.

I'm not understanding the significance of the bold text in your post. You've got a meter with 2 sets of SE conductors on the load side. One set feeds a service disconnect on a panel inside the building. The other set feeds a service disconnect on the outside of the building which powers an A/C condenser that is also outside the building.

My point is that since no part of the A/C service enters the building, why would its disconnect have to be grouped with the building service disconnect?

For example, what if the 2nd set of SE conductors on the load side of the meter fed a separate structure? Would the disconnect for the separate structure need to be adjacent to the disconnect for the main building?

But the HVAC service disconnect does disconnect the service conductors it controls from the premises wiring system. Where's the 230.74 violation?

Just call the HVAC unit an accessory structure, which is permitted its own set of service conductors under 230.40 Exception No. 3, install the grounding electrode system required under 250.24(A), and the service disconnects no longer need to be grouped under 230.72.

Cheers, Wayne
The service disconnect for the separate structure - the AC unit is not on the separate structure though and is not grouped with the other service disconnecting means of the structure it is located on. If anything move the AC unit service disconnect to the AC unit and get it off the building, then provide the needed grounding electrode system and fix any issues with multiple conductors in a lug rated for one conductor at the meter - then we may have a NEC compliant install. When all that is said and done - may have been less cost to get a circuit from the panel on other side of the wall out to this disconnect. If panel is full, or is a FPE, Pushmatic, Zinsco, etc. that changes things cost wise as well.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
The service disconnect for the separate structure - the AC unit is not on the separate structure though and is not grouped with the other service disconnecting means of the structure it is located on. If anything move the AC unit service disconnect to the AC unit and get it off the building, then provide the needed grounding electrode system and fix any issues with multiple conductors in a lug rated for one conductor at the meter - then we may have a NEC compliant install.
Yes, I agree. I forgot about moving the AC unit service disconnect off the house. It's hard to say that the service entrance conductors are "run" to the AC unit per 230.40 Exception 3 when the AC service disconnect is still on the house.

BTW, in reading 230.40 Exception 3 I see it is only for a single family dwelling unit and its accessory structures. Does that mean that for say, a two family dwelling with a detached garage, you can not run a separate set of service entrance conductors to the garage? The garage can only be supplied by a feeder, or you have to convince the POCO to provide a second service drop/lateral to the garage?

Cheers, Wayne
 

north star

Senior Member
Location
inside Area 51
$ + + $


In some AHJ's, ...the "convincing the POCO" is just a matter
of an owner calling the "powers-that-be", and whining & moaning
to them long enough for the AHJ to approve of anything,
...hence the AHJ approves, which means the POCO has covered
their arses. :D



$ + + $
 
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