Transfer Switch for Main Service Disconnect

[bbell]

We are having situations where the installer is taking the service conductors, after the meter in a combination meter main service panel (main bus with combined neutral/equipment grounds) condition and routing the conductors to an ATS. They then run the conductors back to the "main service panel" (the location in which the service entrance conductors originated before and after the meter with the main bussing) with no main disconnect in this panel. The installer is then attempting to claim the ATS is the main service disconnect and is bonding the grounds/neutrals with the jumper wire.

I am finding this to be a direct violation of NEC (CEC in CA) of 250.142 (1) for the required bonding of the grounded conductor. Any thoughts or feedback on this would be appreciated.

 

[augie47]

Normally the 1st means of disconnect would be the service disconnect which in your case would be the meter/main panel (assuming there is a disconnect there) and, as you stated, there should be no neutral to ground connection after that.
Unfortunately with the advent of 230.85 it gets a bit more complicated as the breaker in the meter/main could be an emergency disconnect--not service equipment p[provided that equipment is not "suitable only as service equipment" in which case the ATS could be your service disconnect.
The "devil is in the details" as it depends on the equipment involved, the labeling and the Code cycle.
The above is based on NEC and not CEC

 

[don_resqcapt19]

If it is the typically combination meter/service panel, UL says you can't change the connections between the meter and the main breaker.

 

[tortuga]

We are having situations where the installer is taking the service conductors, after the meter in a combination meter main service panel (main bus with combined neutral/equipment grounds) condition and routing the conductors to an ATS. They then run the conductors back to the "main service panel" (the location in which the service entrance conductors originated before and after the meter with the main bussing) with no main disconnect in this panel.

There are apparently also installers that leave those conductors and remove the ones between the main and the busbar (see photo)
there was a interesting thread about that recently, scroll down to about post 16:

back-fed breaker and generator interconnect

My jurisdiction allows line-side taps, as well as back-fed circuit breakers, for connecting a grid-tied solar inverter. They also allow interlock kits (in the main load center) for generator inlets. If using both a back-fed breaker for the PV inverter, AND an interlock kit for the generator...

forums.mikeholt.com

it seems to be a California thing, here in Oregon as probably most places you cannot remove those factory installed 'service conductors' in the meter/main and keep the listing [230.66 & 110.3(B)] and even if you could looking at the way they terminate would probably be a violation of 312.6:

 

[qcroanoke]

There are apparently also installers that leave those conductors and remove the ones between the main and the busbar (see photo)
there was a interesting thread about that recently, scroll down to about post 16:

back-fed breaker and generator interconnect

My jurisdiction allows line-side taps, as well as back-fed circuit breakers, for connecting a grid-tied solar inverter. They also allow interlock kits (in the main load center) for generator inlets. If using both a back-fed breaker for the PV inverter, AND an interlock kit for the generator...

forums.mikeholt.com

it seems to be a California thing, here in Oregon as probably most places you cannot remove those factory installed 'service conductors' in the meter/main and keep the listing [230.66 & 110.3(B)] and even if you could looking at the way they terminate would probably be a violation of 312.6:
View attachment 2573300

Wow

 

[jaggedben]

We are having situations where the installer is taking the service conductors, after the meter in a combination meter main service panel (main bus with combined neutral/equipment grounds) condition and routing the conductors to an ATS. They then run the conductors back to the "main service panel" (the location in which the service entrance conductors originated before and after the meter with the main bussing) with no main disconnect in this panel. The installer is then attempting to claim the ATS is the main service disconnect and is bonding the grounds/neutrals with the jumper wire.

I am finding this to be a direct violation of NEC (CEC in CA) of 250.142 (1) for the required bonding of the grounded conductor. Any thoughts or feedback on this would be appreciated.

The precise code citation is 250.142(B). But you are correct. Plus the other things mentioned, 110.3(B) etc.

I baffles me a bit that more people don't install separate meter sockets and service panels, as it would often make these conversions so much easier.

 

[bbell]

Thank you all for the feed back. It is agreed that they have violated the listing of their equipment which another component I am working to address in our jurisdiction. We have a lot of contractors performing this type of work with and without permits so I am drafting an industry bulletin to clearly explain the sections of code that address theses scenarios and how one could install these types of equipment with either field re-listing of the equipment or the use of other load center equipment etc. Thanks again for any insights and continued conversations. Cheers!

 

[tom baker]

great idea on industry bulletin!