meter stack in 2020 nec

D

darekelec

Senior Member
Location
nyc
GM
I am jumping from 2008 to 2020 in nyc and I have a question
in 3 family home can I use 3 meter stack for 3 apartments? or do they have to be individual meter cans. metering has service conductors.
 
infinity said:
Can't the multiple service disconnects be in separate compartments of the same enclosure?
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Yes, but the definition of a compartment in UL 67 for this application is an enclosure that meets the requirements of UL 50, the product standard for junction boxes. Don't think that there are any on the market with more than two compartments.
 
don_resqcapt19 said:
Yes, but the definition of a compartment in UL 67 for this application is an enclosure that meets the requirements of UL 50, the product standard for junction boxes. Don't think that there are any on the market with more than two compartments.
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Siemens has 2 through 6 meter/disconnect models.

Don, I know this change is your baby but it has really made things difficult for small multi family dwellings (6 or less meters) and Class 320 combination service entrance devices for single family dwellings.

I can see the safety factor in larger commercial/industrial equipment but for residential equipment its not hard to shut off 2 or 3 service disconnects.

I'm not sure why the manufactures have been so slow in make changes since they have had 6 years to figure it out. Siemens is the only major manufacture to be finally making changes. Square D is discontinuing there Class 320 panels and small meter centers with no replacements
advertised yet.
 
curt swartz said:
I can see the safety factor in larger commercial/industrial equipment but for residential equipment its not hard to shut off 2 or 3 service disconnects.
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The rule has nothing to do with shutting down multiple service disconnects. All of my proposals were asking for each service disconnect to be in a separate compartment from any load side conductors or breakers, like is required in Canada,
 
don_resqcapt19 said:
The rule has nothing to do with shutting down multiple service disconnects. All of my proposals were asking for each service disconnect to be in a separate compartment from any load side conductors or breakers, like is required in Canada,
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If the line side of the disconnects are insulated what is the issue with having multiple disconnects in single enclosure?
 
don_resqcapt19 said:
little pieces of insulating material do little to reduce the potential of an arc flash, they are only intended to provide shock protection.
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Having a single or multiple disconnects doesn't change how the circuit breakers are insulated. A single circuit breaker will often have the same piece of flexible plastic covering the line connections. I would be in favor of having a separate secure metal barrier covering the line conductors/bussing and breaker lugs.
 
don_resqcapt19 said:
little pieces of insulating material do little to reduce the potential of an arc flash, they are only intended to provide shock protection.
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240 single from a relatively high impedance transformer secondary and conductors. Do you personally (not code) think there is much potential for an arc flash event?

I've witnessed a couple of arc flash events one outside a mortuary with a 3p service for the coolers, a couple of ones in the coal industry, and one in a 925 Harris guillotine scrapyard shear. It's nothing like someone dropping a something in a single phase resi box.
 
curt swartz said:
Having a single or multiple disconnects doesn't change how the circuit breakers are insulated. A single circuit breaker will often have the same piece of flexible plastic covering the line connections. I would be in favor of having a separate secure metal barrier covering the line conductors/bussing and breaker lugs.
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That was in one of my rejected proposals.
 
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