EVSE installation w/piercing taps ?

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Smartcharge512

Smartcharge512

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Austin, TX, US
Hi, brand new to forum

I work for an EVSE installation company. We only install car charging systems in commercial and residential. My predecessor manager implemented into our company, using line/supply side piercing taps before the main disconnect or main breaker, and feeding a fusible 2 space breaker enclosure and providing the appropriate size breaker to then feed our EVSE.

We've never been corrected on this until recently on a job out of town, inspector quoted article 240.21 "you can't tap a tap"

Are we doing this incorrect ? It's has been the fastest way for us to install our evse, in full panels. Without just setting a sub panel and relocating circuits also where installing more tandems isn't allowable.

Can someone also tell me how to add a picture for ex. Off an iPad ??
 
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I don't see where 230.82 applies here. You are just adding an additional service disconnect. I could see issues 230.72 depending on the location of the existing disconnect and of the new one.
 

Although the original service conductors are protected only by OCPD at the downstream end they are not a tap as defined by the NEC. Only feeder and branch conductors can be tapped.

I agree that this is (except for the muddy nature of the PV disconnect) just another service disconnect. If full service size conductors were required to each disconnect there would be a lot of industrial and multi-occupancy services in violation.

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GoldDigger said:

Although the original service conductors are protected only by OCPD at the downstream end they are not a tap as defined by the NEC. Only feeder and branch conductors can be tapped.

I agree that this is (except for the muddy nature of the PV disconnect) just another service disconnect. If full service size conductors were required to each disconnect there would be a lot of industrial and multi-occupancy services in violation.

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So to be clear there is NOT a violation to do this ? We fed a Nema 14-50 off of the service disconnect that we used the piercing taps to feed.
 
Smartcharge512 said:
So to be clear there is NOT a violation to do this ? We fed a Nema 14-50 off of the service disconnect that we used the piercing taps to feed.
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Since it is not for PV backfeed, I would say that it is indisputable.
Depending on the code cycle you are under, there might be some small room for AHJ interpretation on PV only, which does not apply to you.
 
The panel shown is an MLO. I'm assuming the main disconnect for it is outside. Since the new panel is also now a service disconnect, don't they both have to be grouped together so they can be shut off in an emergency?
 
Coppersmith said:
The panel shown is an MLO. I'm assuming the main disconnect for it is outside. Since the new panel is also now a service disconnect, don't they both have to be grouped together so they can be shut off in an emergency?
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Yes, that was mentioned in an earlier post. Also, if the interior panel does have an outside service disconnect, the wires coming into your panel would be feeders rather than service, and you could not tap them if they were themselves not protected fully by the outside OCPD.
Coming into an MLO panel it is almost certain that they are fully protected at the supply end. In that case your wiring would be a feeder tap and would have to be sized according to the applicable rules based on length.
 
G
GoldDigger said:
Yes, that was mentioned in an earlier post. Also, if the interior panel does have an outside service disconnect, the wires coming into your panel would be feeders rather than service, and you could not tap them if they were themselves not protected fully by the outside OCPD.
Coming into an MLO panel it is almost certain that they are fully protected at the supply end. In that case your wiring would be a feeder tap and would have to be sized according to the applicable rules based on length.
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The MLO is protected by an outside main disconnect, and the tapped conductors are minimum #6 awg
 
You're pictures show a feeder tap, not a supply side tap as you described in your original post.

In this case I don't see any violation as long as 240.21(B) rules are followed, nor do I see any obvious violation of those rules. I have no idea what the inspector would mean by "you can't tap a tap", either in general or in this specific case.

The rules for an actual additional service disconnect are different, as has been discussed upthread.
 
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