Multi meter service

[Ponchik]

I don't quiet fully understand the 2020 NEC requirement for multi disconnect service. With partition and/or main disconnect details...

Is this OK for installation?

Thanks in advance.

2 new photos · Tuesday, Jul 25, 2023 ð¸

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[electrofelon]

I don't quiet fully understand the 2020 NEC requirement for multi disconnect service. With partition and/or main disconnect details...

Is this OK for installation?

Thanks in advance.

2 new photos · Tuesday, Jul 25, 2023 ð¸

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photos.app.goo.gl

I don't believe so . I believe for meter assemblies the wording is "separate compartments".. I don't believe there is currently any metering equipment available that meets that requirement - at least that was the word on the street last year. Anybody have any updates?

Yet another genius NEC thing where they require something and there's no equipment available, thanks NFPA, good work

 

[mtnelect]

I don't believe so . I believe for meter assemblies the wording is "separate compartments".. I don't believe there is currently any metering equipment available that meets that requirement - at least that was the word on the street last year. Anybody have any updates?

Yet another genius NEC thing where they require something and there's no equipment available, thanks NFPA, good work

As I understand it .... There now needs to be one Main Disconnect for the property severed. So, when the fire department arrives, they can turn the power off with on throw.

 

[electrofelon]

As I understand it .... There now needs to be one Main Disconnect for the property severed. So, when the fire department arrives, they can turn the power off with on throw.

That is not correct.

 

[hillbilly1]

You still have the six throws, it just has to be in separate enclosures. Not really sure what they were trying to accomplish, maybe less exposure to arc flash?

 

[Ponchik]

You still have the six throws, it just has to be in separate enclosures. Not really sure what they were trying to accomplish, maybe less exposure to arc flash?

And if they are not separate enclosure/compartment then a main disconnect is required.That's the way I read it but I am not sure about my interpretation.

 

[electrofelon]

And if they are not separate enclosure/compartment then a main disconnect is required.That's the way I read it but I am not sure about my interpretation.

I think there are two different requirements being thrown around here. One is the outside emergency disconnect for one and two family dwellings, 230.85. The other is the "MLO prohibition" which requires service disconnects to be in separate enclosures, 230.71

 

[electrofelon]

230.71(B) Two to Six Service Disconnecting Means. Two to six service disconnects shall be permitted for each service permitted by 230.2 or for each set of service-entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5. The two to six service disconnecting means shall be permitted to consist of a combination of any of the following:

(1) Separate enclosures with a main service disconnecting means in each enclosure

(2) Panelboards with a main service disconnecting means in each panelboard enclosure

(3) Switchboard(s) where there is only one service disconnect in each separate vertical section where there are barriers separating each vertical section

(4) Service disconnects in switchgear or metering centers where each disconnect is located in a separate compartment

 

[hillbilly1]

And if they are not separate enclosure/compartment then a main disconnect is required.That's the way I read it but I am not sure about my interpretation.

I think if they had dividers between each disconnect, the product you posted would meet the requirements, but it doesn’t look like there is any separation.

 

[don_resqcapt19]

You still have the six throws, it just has to be in separate enclosures. Not really sure what they were trying to accomplish, maybe less exposure to arc flash?

The exact purpose of the code change. It needs to go one step more and prohibit any other OCPD from being in the same enclosure with the service OCPD.

 

[don_resqcapt19]

I think if they had dividers between each disconnect, the product you posted would meet the requirements, but it doesn’t look like there is any separation.

UL 67 has been revised and now specifies that the compartments that a divider would create have to be constructed in accordance with UL 50, the standard that covers the construction of junction boxes, so a complete enclosure or compartment for each disconnect.

 

[jaggedben]

And if they are not separate enclosure/compartment then a main disconnect is required.That's the way I read it but I am not sure about my interpretation.

I'm not sure this is the most helpful way to think about it, because putting a main disconnect ahead isn't always going to be a permitted way to fix a problem with equipment you have.

A case in point,: the meter pack you show in your pics. It has a bonded neutral bus, so it can only be used as service equipment. To use that meter pack with a main disconnect you'd violate either 250.25(A)(5) or arguably 110.3(B) if you modified it. Perhaps in this case you could remove the neutral bar entirely and tap to wires instead, but it's borderline.

This is aside from whether the utility will allow you to have a disconnect ahead of meters (although the NEC doesn't care about that.)

 

[Ponchik]

I'm not sure this is the most helpful way to think about it, because putting a main disconnect ahead isn't always going to be a permitted way to fix a problem with equipment you have.

A case in point,: the meter pack you show in your pics. It has a bonded neutral bus, so it can only be used as service equipment. To use that meter pack with a main disconnect you'd violate either 250.25(A)(5) or arguably 110.3(B) if you modified it. Perhaps in this case you could remove the neutral bar entirely and tap to wires instead, but it's borderline.

This is aside from whether the utility will allow you to have a disconnect ahead of meters (although the NEC doesn't care about that.)

I am not modifying the enclosure. I don't want to open another ball of wax.

I have contacted the head inspector to see if he will allow this panel to be installed.

FWIW, this is my chat with Schneider customer service representative:

 

[electrofelon]

I'm not sure this is the most helpful way to think about it, because putting a main disconnect ahead isn't always going to be a permitted way to fix a problem with equipment you have.

A case in point,: the meter pack you show in your pics. It has a bonded neutral bus, so it can only be used as service equipment. To use that meter pack with a main disconnect you'd violate either 250.25(A)(5) or arguably 110.3(B) if you modified it. Perhaps in this case you could remove the neutral bar entirely and tap to wires instead, but it's borderline.

This is aside from whether the utility will allow you to have a disconnect ahead of meters (although the NEC doesn't care about that.)

There is an exception that allows meter enclosures past the service disconnect to be bonded. 250.142(B) exception number two.

 

[jaggedben]

There is an exception that allows meter enclosures past the service disconnect to be bonded. 250.142(B) exception number two.

Good point. But his equipment also has overcurrent protection.

I think appealing to the AHJ per 90.4 paragraph 3 is very appropriate in these cases.

 

[electrofelon]

Good point. But his equipment also has overcurrent protection.

I think appealing to the AHJ per 90.4 paragraph 3 is very appropriate in these cases.

Why would it matter whether his equipment also has overcurrent protection? Are you saying that equipment might not be covered by the exception then?