Meter disconnect switches

[ryan_618]

New to the 2005 is this subsection to 230.82, for equipment installed on the line side of the service disconnect:

(3) Meter disconnect switches nominally rated not in excess of 600 volts that have a short-circuit current rating equal to or greater than the available short circuit current, provided all metal housings and service enclosures are grounded

My question is, if you have a disconnect on the supply side of the service, doesn't that make it the service disconnect? I have heard this is for a very particular type of equipment, but I have never seen it. Does anyone have any info about it?

 

[bphgravity]

Re: Meter disconnect switches

I think techcically yes, but that wasn't the intention.

This change appears to allow for a disconnect identified as a "meter disconnect switch" ahead of the meter and ahead of another disconnect identified as the "service disconnect". Obviously, the meter disconnect switch could be used as a service disconnect.

It appears to me this simply means you are permitted to have a disconnect ahead of another disconnect and not have to treat the second disconnect as a "sub-panel" as long as the first disconnect's purpose is to disconnect the meter equipment.

 

[throttlebody]

Re: Meter disconnect switches

The 3 pocos here (No VA)requires a fused disconnect switch ahead of the meter @ 277/480V to ensure that there is no load on the meter if it needs pulled.

The disconnect after the meter is treated as the service disconnect.

We were in a ruffle here as the elec contractor is required to supply the disconnect and cables ahead of the meter. This makes the equipment belong to the consumer, but maintenance of the poco. The pocos want to lock it down so no unmetered taps could be made before the metered tap, but will not service the parts needing replaced. If one of the fuses blow, they have to contact the poco to unlock it for replacement of the fuse, which obviously could not be made in a timely manner. If only a non-fused switch was used................anyway, 1 of the pocos has changed this to a CT instead. :roll:

[ February 13, 2006, 11:59 AM: Message edited by: throttlebody ]

 

[tom baker]

Re: Meter disconnect switches

Ryan, our POCO has required a disconnect ahead of the meter since 1982 for services over 300 V phase to phase.
Typically I will install two, one ahead of the meter, non fused, if the available AIC is 10K or less, and a second inside the bulding with fuses.

The one inside the bulding in this case is the service disconnect. The other is the POCO's with their lock

If the disconnect ahead of the meter has fuses, it gets tricker. In that case its the customers meter, with the customers lock

The western states require this type of cold sequence meter under USERC. Mike Holt a few years ago had never heard of it.

 

[throttlebody]

Re: Meter disconnect switches

Originally posted by tom baker:

If the disconnect ahead of the meter has fuses, it gets tricker. In that case its the customers meter, with the customers lock

That's where our problem lyes with the pocos here, they are currently providing the lock without distribution of the key to the customer.
They politely showed sway to a customer, since a mentioning of boltcutters was made. We are currently not accepting fused disconnects until property matters get resolved.

 

[charlie]

Re: Meter disconnect switches

We require our meters on the downtown network to be in cold sequence. If a meter disconnect is used, it must be only a lockable disconnecting means and will be locked by us. The downstream disconnecting means and overcurrent device will then be the service equipment. If a service is installed ahead of the meter, we will meter the feeder to the distribution panelboard.

 

[pete m.]

Re: Meter disconnect switches

My question, in line with Ryans, is... why doesn't the NEC give us a clear definition of "service disconnect"

 

[bdarnell]

Re: Meter disconnect switches

Originally posted by charlie:
We require our meters on the downtown network to be in cold sequence.

And they have to be 200 kAIC. I found that out the hard way a long time ago, Charlie.

 

[charlie]

Re: Meter disconnect switches

Brad, when you have as many as six large transformers feeding into a single vault via the network, the available fault current tends to go up a bit.