Service Entrance requirements for non utility transformer

[walletsworth]

I have always provided UL service equipment for anything fed from a transformer even if it's a 150kVA that I provided and not the utility. The switchgear company that provided the material to my customer is telling me that it isn't required. My customer begs to differ and I tend to agree with him since it is always what I have provided. Anyone else run into this before? I haven't been able to reach the inspector but I'm assuming he will want that UL label on the panel.

 

[augie47]

The NEC for the most part requires that equipment be "Approved" (Their are some instances where it does require listing).
Approval is up to the Authority Having Jurisdiction (AHJ).
Many AHJs rely on listing before approving equipment. Most require listing by one of the OSHA recognized NRTLs such as UL.
In addition OSHA requires listing (with exceptions)

 

[jtinge]

Is your question trying to clarify if you should use service entrance equipment or distribution equipment if fed by a transformer not owned by the POCO or is it more concerned with the listing of the equipment?

If it is about the use of service entrance equipment, "service" by definition means fed by the utility. So if the transformer is not owned by the utility, you don't need service entrance equipment and Article 230 wouldn't apply. It's more likely that Article 220 and/or 225 requirements are applicable since the transformer is not owned by the POCO.

If your question is whether equipment needs to be listed or not, that may come down to what is acceptable to the AHJ.

 

[augie47]

jtinge: Good read (and post). I assumed happysad the question dealt with "listing" and not "service listing". Glad you read closer.

 

[david]

If it is about the use of service entrance equipment, "service" by definition means fed by the utility. So if the transformer is not owned by the utility,

you don't need service entrance equipment

If your question is whether equipment needs to be listed or not, that may come down to what is acceptable to the AHJ.

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.
Exception: For garages and outbuildings on residential property, a snap switch or a set of 3-way or 4-way snap switches shall be permitted as the disconnecting means.

 

[jtinge]

jtinge: Good read (and post). I assumed happysad the question dealt with "listing" and not "service listing". Glad you read closer.

Thanks. Once in a while I'm able to provide a lucid, rationale, well thought out explanation. (Ref. "My Cousin Vinny!)

The switchgear company that provided the material to my customer is telling me that it isn't required.

I suspect the switchgear company is saying service entrance equipment isn't required, and not referring to the listing, since service entrance equipment is required to be listed per 250.66.

230.66 Marking
Service equipment rated at 1000 volts or less shall be marked
to identify it as being suitable for use as service equipment. All
service equipment shall be listed. Individual meter socket enclosures
shall not be considered service equipment.

Discussions in previous threads pointed out that service equipment is designed to accommodate power sources which are unfused (at least in proportion to the nominal conductor size) and can deliver very large fault currents. Equipment not designated as service entrance equipment may not be designed for connection to this type of power source. If you are not supplied by a service, there is no need to utilize service entrance equipment, especially when non-service equipment will serve the purpose.

 

[jtinge]

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.
Exception: For garages and outbuildings on residential property, a snap switch or a set of 3-way or 4-way snap switches shall be permitted as the disconnecting means.

This may or may not be the case depending upon which code cycle you are on. This was revised for the 2014 Code cycle.

225.36 Type
The disconnecting means specified in 225.31 shall be comprised
of a circuit breaker, molded case switch, general-use switch, snap
switch, or other approved means. Where applied in accordance
with 250.32(B), Exception No. 1, the disconnecting means shall
be suitable for use as service equipment.

 

[david]

If it is about the use of service entrance equipment, "service" by definition means fed by the utility. So if the transformer is not owned by the utility, you don't need service entrance equipment

This may or may not be the case depending upon which code cycle you are on. This was revised for the 2014 Code cycle.

225.36 Type
The disconnecting means specified in 225.31 shall be comprised
of a circuit breaker, molded case switch, general-use switch, snap
switch, or other approved means. Where applied in accordance
with 250.32(B), Exception No. 1, the disconnecting means shall
be suitable for use as service equipment.

I don?t have the 2014 edition so I?m not sure what 250.32(B), Exception No. 1 is,
I think your statement needed clarification when you said equipment suitable for use for a service was only required when the source was a utility service.

 

[david]

This may or may not be the case depending upon which code cycle you are on. This was revised for the 2014 Code cycle.

I checked Mike Holts home page ND will adopt the 2014 effective 9/1/2014

 

[jtinge]

I don?t have the 2014 edition so I?m not sure what 250.32(B), Exception No. 1 is,
I think your statement needed clarification when you said equipment suitable for use for a service was only required when the source was a utility service.

You are correct. Thanks for clarifying. I've included 250.32(B)(1), Exception No. 1 and 2, and the handbook commentary for 225.36 for context.

250.32
(B) Grounded Systems.
(1) Supplied by a Feeder or Branch Circuit. An equipment
grounding conductor, as described in 250.118, shall be run with
the supply conductors and be connected to the building or structure
disconnecting means and to the grounding electrode(s ). The
equipment grounding conductor shall be used for grounding

Exception No. 1: For installations made in compliance with
previous editions of this Code that permitted such connection,
the grounded conductor run with the supply to the building
or structure shall be permitted to serve as the ground-fault
return path if all of the following requirements continue to
be met:

(1) An equipment grounding conductor is not run with the
supply to the building or structure.
(2) There are no continuous metallic paths bonded to the
grounding system in each building or structure involved.
(3) Ground-fault protection of equipment has not been installed
on the supply side of the feeder(s).

If the grounded conductor is used for grounding in accordance
with the provision of this exception, the size of the grounded
conductor shall not be smaller than the larger of either of the
following:

(1) That required by 220.61
(2) That required by 250.122

Exception No. 2: If a building or structure is supplied by a
feeder from an outdoor transformer, a system bonding jumper
at both the source and the first disconnecting means shall be
permitted if doing so does not establish a parallel path for the
grounded conductor. If a grounded conductor is used in this
manner, it shall not be smaller than the size specified for the
system bonding jumper but shall not be required to be larger
than the ungrounded conductor(s). For the purposes of this
exception, connection through the earth shall not be considered
as providing a parallel path.

225.36 Hdbk Commentary
This section was revised for the 2014 Code. The feeder or branch circuit
disconnecting means is required to be suitable for use as service
equipment only where the feeder grounded conductor is also
used as the return path for ground-fault current per 250.32(B)(1),
Exceptions No. 1 and No. 2. The exception permitting a three- or
four-way snap switch to be used as a disconnecting means for an
outside branch circuit or feeder was deleted because it would not
provide a positive indication that the circuit was disconnected.

 

[david]

Thanks for clarifying. I've included 250.32(B)(1), Exception No. 1 and 2, and the handbook commentary for 225.36 for context.

I didn?t clarify it I presented you with the opportunity to clarify your statement,
You seemed to have done a good job of clarifying it.

 

[walletsworth]

Thanks for all the feedback. This was an eye opener. It looks like we have to find out what the AHJ is going to require and go from there.