tap tap tap!

Coppersmith

Senior Member
Location
Tampa, FL, USA
A client of mine who is a solar contractor has installed the system depicted below. His approved drawing calls for a line side tap. The inspector says this is a supply side tap. It's on the line side of the panel but the supply side of the MB. What is the correct answer?

If that is a supply side tap, does moving the tap to the line side of the MB make it a line side tap? Note that there is already a tap ahead of it to another panel.

He used those taps that bite into the wire. If those are removed, can the insulation be repaired with tape (vinyl or rubber) and stay compliant? If not, could he leave them in place and just disconnect the tap wires and be compliant?

Solar System Tap.jpg
 

GoldDigger

Moderator
Staff member
Based on the diagram, the "panel B main breaker, which is not physically in panel B, is a service disconnect, with the main breaker in panel A also being a service disconnect. (Are they grouped?)
That makes the PV connection a load side tap supplying the panel B bus but not located at the opposite end of the bus from the MB. Probably a violation, depending on the details of bus B rating, MB rating PV rating and sum of branch breakers.

Sent from my XT1585 using Tapatalk
 

wwhitney

Senior Member
Location
Berkeley, CA
That's a load side connection, so it doesn't match the approved drawings.

Is panel B itself MLO? If so, then the NEC requires the feeder downstream of the PV tap, and the bus in panel B, to be rated at least the sum of the Panel B service disconnect breaker size and 125% of the inverter output current.


Cheers, Wayne
 

Fulthrotl

~~Please excuse the mess. Sig under construction~~
He used those taps that bite into the wire. If those are removed, can the insulation be repaired with tape (vinyl or rubber) and stay compliant? If not, could he leave them in place and just disconnect the tap wires and be compliant?
cup-L-taps, or similar ilk, can be removed, and the damaged
insulation repaired as any other nicked insulation would be.

or i suspect you could leave them on, removing the tap, and
just torquing them down. i'd remove them and use 2 layers of
half lapped scotch 33, and move on.
 

jaggedben

Senior Member
A client of mine who is a solar contractor has installed the system depicted below. His approved drawing calls for a line side tap. The inspector says this is a supply side tap. It's on the line side of the panel but the [load] side of the MB. What is the correct answer?

If that is a supply side tap, does moving the tap to the line side of the MB make it a line side tap? Note that there is already a tap ahead of it to another panel.


View attachment 21391
Terminology seems off the mark in your post. 'Line' and 'supply' are synonyms here. In the above quote I changed one instance of 'supply' to 'load' because that's what your diagram indeed shows (a tap on the load side of the MB, not the supply side]. In the other instances of 'supply' some clarification might be in order. What exactly did the inspector call which?

He used those taps that bite into the wire. If those are removed, can the insulation be repaired with tape (vinyl or rubber) and stay compliant?
In my opinion yes.

If not, could he leave them in place and just disconnect the tap wires and be compliant?
I'd be a bit more concerned about exposed live parts inside those than conductor insulation repaired with tape. Still calls for tape around open holes, in my opinion.
 

Coppersmith

Senior Member
Location
Tampa, FL, USA
Terminology seems off the mark in your post. 'Line' and 'supply' are synonyms here.
After a bit of research I agree. I was using the terminology the solar contractor told me. I also reviewed the drawing and found the engineer said "supply side" and showed a diagram where the taps are between the meter and the panel main. He doesn't show the separate main breaker before the panel.

Based on the diagram, the "panel B main breaker, which is not physically in panel B, is a service disconnect, with the main breaker in panel A also being a service disconnect.
That's a load side connection, so it doesn't match the approved drawings.
So if we move the tap above the "service disconnect" (which would be right after the meter), does that make it line/supply side?

(Are they grouped?)
No they are not, but pre-exisiting so not an issue I hope.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
They appear to be replacements for the tops of the lugs inside the meter can that allow the attachment of a tap conductor. I've never seen the tap done inside the meter can but I can't think of a reason you couldn't do it.
One reason would be if the AHJ will not allow it; none around here will.
 

Coppersmith

Senior Member
Location
Tampa, FL, USA
They appear to be replacements for the tops of the lugs inside the meter can that allow the attachment of a tap conductor. I've never seen the tap done inside the meter can but I can't think of a reason you couldn't do it.
Now that I've thought about it, one type of tap I see routinely in the meter can is a surge protector. The leads are just placed under the same lug as the feeders. That has always struck me as a violation, but it's allowed by the inspectors.

One reason would be if the AHJ will not allow it; none around here will.
Is there a code section that disallows it?
 

Adamjamma

Senior Member
I don't know, but all the AHJ's around here won't let you do it (tap inside their meter can).
is it the AHJ or the POCO? In Jamaica the POCO wants me to run separate wires up the mast for each meter, in their own conduits.. so they can cut off the power away from the meter can because of theft...
 

jumper

Senior Member
I don't know, but all the AHJ's around here won't let you do it (tap inside their meter can).
One reason could be that they are enforcing a POCO spec because they know that it will not get energized.

Dominion VA allows nothing in theirs beyond standard service conductors and in VA, the inspector calls POCO to energize after inspections, so basically if one tried to land the GEC in the meter base, legal per NEC, you still fail as you will not get power from POCO.
 

Adamjamma

Senior Member
which is funny because in Jamaica, even though the meter is placed in a concrete post with rebar in the post, and usually on a property concrete boundry fence with rebar in the fence foundations, you must run a conduit and a ground wire to the meter, the meter may not be bonded to the rebar in any way, and the Poco tests to make sure that the meter is separate from the rebar with a meter... have had to repair a post where they chiseled to the rebar to place their meter lead to it... If I want to support the meter box to the rebar as part of the concrete pouring process I have to use insulated means of support... The ground spike used for grounding the meter cannot be joined to the fence rebar or to the house rebar...

I think they are wrong but that is how they want it done, even at a house where their transformer is grounded right at the pole beside the meter... We had to move the ground rod ten feet away from the POCO ground rod for the pole before they were satisfied with their meter reading....lol
 
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