grouped disconnects

[brown]

230-46 states that one service can feed up to six disconnecting means if grouped in one location.
I have installed a 400 amp meter enclosure which feeds two 200 amp disconnect switches. One switch is located in a controled area directly on the opposite side of a wall from the meter enclosure.
The other switch is located next to the meter enclosure and is used to supply power to an attached building. The two buildings are owned by the same people and are used as a business.
Because of limited space I chose to leave the 200 amp disconnect switch in the existing location of the controled area. The second disconnect switch was installed next to the meter enclosure.
My problem is what is meant by common location? Do they actually have to be grouped and visable in the same area or can they be on opposiste sides of the wall if a plaque is installed to state where the disconnect switches are and their intended function.
The inspection department says the disconnects can be used as is if there is a plaque.
Can you help me, Please!
There is only one service lateral to the building.

 

[jwelectric]

Re: grouped disconnects

If one is on the inside and one is on the outside that would be differant locations.

2005 code
230.72 Grouping of Disconnects.
(A) General. The two to six disconnects as permitted in 230.71 shall be grouped. Each disconnect shall be marked to indicate the load served.
Exception: One of the two to six service disconnecting means permitted in 230.71, where used only for a water pump also intended to provide fire protection, shall be permitted to be located remote from the other disconnecting means.

if either disconnect is soley for a fire pomp I see no problem

 

[benaround]

Re: grouped disconnects

Get some real nice signage on them.

frank

 

[electrofelon]

Re: grouped disconnects

This area has always has seemed a little gray to me, that is the 2 gang or 400A meter pan with two sets of service entrance conductors. For example, tell me where having two service panels, one in each unit, in say a duplex type of dwelling is permnitted by NEC. Its common practice in every juristiction ive worked in. There is also the arrangement like yours, where you have a Dual lug meter, one set of of SE conductors feeding a main breaker service panel in the house, and anothe set feeding a main breaker panel in the garage. Where is the grouping of disconnects there? This too is common practice where I am. Whats going on here?

 

[mc5w]

Re: grouped disconnects

You definitely need the plaques. Every class 320 meter socket on the market is lever bypass jaw release and is NOT rated for use as an emergency disconnect by the fire department. Doing so can cause the meter socket to burn down or explode as the bypass contacts are not load break rated.

The correct way for the fire department to shut off power is to cut the service switch(es), then pull the meter. When the electrical utility dosconnects for nonpayment they are supposed to replace the meter with a circuit breaker that plugs into the socket. They then turn off the circuit breaker, remove the breaker, put insulating boots on the meter prongs, then reinstall the meter. Load make is not a problem when restoring service after the bill is paid.

The same procedure is also supposed to be used with horn bypass meter sockets. Most utilites now require that direct wired meter sockets have some type of bypass so that they can use a circuit breaker. Breaking say 20 amps of load on 240 volts single phase by pulling the meter is not that bad, but breaking 120 amps 120Y208 volts or 277Y480 volts can lead to a 3-phase flashover.

[ April 21, 2005, 05:16 AM: Message edited by: mc5w ]

 

[don_resqcapt19]

Re: grouped disconnects

electrofelon,

For example, tell me where having two service panels, one in each unit, in say a duplex type of dwelling is permitted by NEC.

Look at 230.40 Exception #1 in the 2005 code. This section permits each occupancy (each side of the duplex) to have its own set of service conductors. Then look at 230.71(A) which permits up to six disconnects for each set of service entrance conductors and then look at 230.72. This section requires that the disconnects for each set of service entrance conductors be grouped with the other disconnects for that set of service conductors. They are not required to be grouped with the service disconnects for other sets of service entrance conductors. Note that this is not as clear in the 2002 code, but was the intent of the 2002 code. Wording changes in the 2005 code made the section easier to understand.

There is also the arrangement like yours, where you have a Dual lug meter, one set of SE conductors feeding a main breaker service panel in the house, and another set feeding a main breaker panel in the garage. Where is the grouping of disconnects there?

See 230.40 Exception #3. This permits a second set of service entrance conductors for the garage. Again each set of service entrance conductors is permitted to have up to six grouped disconnects.
Don

 

[electrofelon]

Re: grouped disconnects

Don,
Thanks for clearing that up. I dont have the 2005 book yet, but thats good that they made that more clear. I see my err in the garage situation: the 6 disco rule applys to SE conductors, not the whole service. Thanks again.

Ethan