Is main disconnect required in condo?

**JB Thompson** · 04-01-2010, 05:09 PM

I've got a question about a condo I inspected today. The electric panelboard had no main disconnect. I know the code for single-family dwellings, but had assumed a main disconnect would be required here as well. This is a multi-family dwelling (more than 4 units).

I also wondered about the service entrance cable being undersized. Photo attached.

Thanks
Bruce

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**Jerry Peck** · 04-01-2010, 05:27 PM

Originally Posted by JB Thompson

I've got a question about a condo I inspected today.

"condo" being the key word ... where is "the service equipment" located in that condo?

The electric panelboard had no main disconnect.

Well, you did call it by the correct term ... "panelboard" ... and that panel is not the service equipment, and as such no main disconnect is required.

I know the code for single-family dwellings,

Okay, where is the main service disconnect located for single-family dwelling units? Answer: At the "service equipment".

Condos are only different in that the location of the "service equipment" is different.

I also wondered about the service entrance cable being undersized.

Why is the service entrance cable undersized?

**JB Thompson** · 04-01-2010, 05:46 PM

Originally Posted by Jerry Peck

"condo" being the key word ... where is "the service equipment" located in that condo?

Well, you did call it by the correct term ... "panelboard" ... and that panel is not the service equipment, and as such no main disconnect is required

Okay, where is the main service disconnect located for single-family dwelling units? Answer: At the "service equipment".

Condos are only different in that the location of the "service equipment" is different.

Why is the service entrance cable undersized?

OK, so the service equipment is located where the underground service rises out of the ground near the meter bank, which is a great distance from this 4th floor unit. If there is a requirement that, in my single family dwelling, I need a main disconnect or that I cannot have more than 6 breakers without a main, why is that different just because it's a condo? (I realize I'm going beyond the original question by asking intent)

Thanks,
Bruce

**Jerry Peck** · 04-01-2010, 05:52 PM

Originally Posted by JB Thompson

OK, so the service equipment is located where the underground service rises out of the ground near the meter bank, which is a great distance from this 4th floor unit.

Just like the main disconnect on the outside of the house, in the garage, or in the basement, is a "great distance" from the far end of the house ... only the "great distance" varies between the condo and the house, the service equipment and panels installations do not.

If there is a requirement that, in my single family dwelling, I need a main disconnect or that I cannot have more than 6 breakers without a main, why is that different just because it's a condo? (I realize I'm going beyond the original question by asking intent)

There is no requirement for that in your house either.

Think about where the service equipment is in the house and where the panel is - that the example that the house has the service equipment "outside" and the "panel" is in the hallway. Okay, now where is the main service disconnect and is there any requirement for 6 or fewer breakers in the "panel"?

**JB Thompson** · 04-01-2010, 06:18 PM

Originally Posted by Jerry Peck

Just like the main disconnect on the outside of the house, in the garage, or in the basement, is a "great distance" from the far end of the house ... only the "great distance" varies between the condo and the house, the service equipment and panels installations do not.

There is no requirement for that in your house either.

Think about where the service equipment is in the house and where the panel is - that the example that the house has the service equipment "outside" and the "panel" is in the hallway. Okay, now where is the main service disconnect and is there any requirement for 6 or fewer breakers in the "panel"?

I'm not following.

I do understand your comments about "service" entering the home and there might be a great distance from the meter (service) to the panel (other side of the home).

OK, so the "service" travels via the "service entrance cables" to the panel. The first point of contact in the panel is the main disconnect.

I'm required to have a main disconnect that disconnects the service from the branches. It happens to be in my electric cabinet containing my panel board. Is that what you're saying? I still don't understand why a condo would be different. What is the intent for having the main? Is it for being able to rapidly turn off all of the branch circuits in case of emergency and for shutting power down to work on it?

I thought there was a requirement that said if a panel had more than six breakers, a main disconnect was required.

Thanks for being patient

**Jerry Peck** · 04-01-2010, 06:36 PM

Originally Posted by JB Thompson

OK, so the "service" travels via the "service entrance cables" to the panel. The first point of contact in the panel is the main disconnect.

Nope.

The "service entrance conductors" go from the meter to the service equipment, which is outside.

The "feeder" conductors travel from the service equipment to the panel inside.

I'm required to have a main disconnect that disconnects the service from the branches.

No you are not. You are required to disconnect all the power with less than 6 breakers, and in this case that is one single main disconnect on the outside of the house. The feeder conductors now go to the panel inside, where you can have 42 breakers (used to be, now it is more).

It happens to be in my electric cabinet containing my panel board.

You mean your service equipment is the same enclosure as your panel, which makes the panel a "service equipment panel", in which you either need one main service disconnect or up to six main service disconnects.

Which is no different than in the condo.

I still don't understand why a condo would be different.

It isn't any different.

There is "service equipment" "for the structure", and the condo is "one structure", just like your house is "one structure".

The condo "structure" contains separate dwelling units, but they are all contained within the same "structure".

What is the intent for having the main? Is it for being able to rapidly turn off all of the branch circuits in case of emergency and for shutting power down to work on it?

Nope.

To be able to turn off all power to "the structure" with 6 or fewer breakers.

I thought there was a requirement that said if a panel had more than six breakers, a main disconnect was required.

Only if the panel is a "service equipment panel" - see above.

The difference is your house is "one structure" with "one dwelling unit" in it, while a condo is "one structure" with "more than one dwelling unit" in it.

The service equipment protects "the structure".

**Jim Hintz** · 04-29-2010, 11:03 PM

Jerry,

I too had a condo today. Is twisting / combining a majority of the branch circuit grounds and installing them into one terminal on the grounding bus allowed? This was originally an apartment in 1984, now a condo conversion. - I.T.E. 125 Amp panel. Also, had a house last week with similar situation - outlet testers (2 different brands) indicated open/missing ground on several outlets, pulled two outlets out of J boxes and ground wires were connected and secure at outlets. Combined ground wires in panel were oxidized at bus connection.

Thanks,
Jim Hintz

**Bruce Ramsey** · 04-30-2010, 08:43 AM

Look at the labeling on the panel itself. Most indicate the maximum number of wires under a single set screw is 2. Very infrequently they allow 3. They must be all of the same size.

No, you cannot lump a bunch of wires under a single screw.

James Duffin · 04-30-2010, 10:09 AM

Originally Posted by JB Thompson

I've got a question about a condo I inspected today. The electric panelboard had no main disconnect. I know the code for single-family dwellings, but had assumed a main disconnect would be required here as well. This is a multi-family dwelling (more than 4 units).

I also wondered about the service entrance cable being undersized. Photo attached.

Thanks
Bruce

The code states that a building can have only one service entrance (there are exceptions but in this case they do not apply). At this service entrance is where you have the main breaker(s). Any panel downstream for the service does not need a main breaker since it is not the service.

**Jerry Peck** · 04-30-2010, 08:43 PM

Originally Posted by James Duffin

The Any panel downstream for the service does not need a main breaker since it is not the service.

There is also nothing wrong with, and no prohibition against, putting a "panel main" in that downstream panel in the condo.

In fact, it adds another level of protection and convenience. Not required, no, but nothing wrong with having a "panel main" either.

**Jim Hintz** · 04-30-2010, 08:57 PM

Originally Posted by Bruce Ramsey

Look at the labeling on the panel itself. Most indicate the maximum number of wires under a single set screw is 2. Very infrequently they allow 3. They must be all of the same size.

No, you cannot lump a bunch of wires under a single screw.

Thanks Bruce - much appreciated !!!

**Bill Kriegh** · 05-01-2010, 03:27 AM

Originally Posted by Bruce Ramsey

Look at the labeling on the panel itself. Most indicate the maximum number of wires under a single set screw is 2. Very infrequently they allow 3. They must be all of the same size.

No, you cannot lump a bunch of wires under a single screw.

Many panels have a buss that can have up to 3 ground wires installed per position, and it is NOT always required that they be the same size.

Whether you can "lump" a bunch of wires under a screw depends on how many and what sizes a "lump" consists of and whether or not the "lump" consists of ungrounded (hot) conductors, grounded conductors (neutral), or grounding conductors. It may also depend on the make and type of breaker. Hardly a good term to be used to describe how many wires go where.

Exposed copper will always oxidize. Whether this is an issue in the panel will depend on whether the screws are properly torqued on the bussbars and breakers.