Commercial Plan Review
Land Use and Environmental Service Agency
(Code Enforcement)
Electrical Q&A 2009
Fourth Quarter 2009
General:
1.
(Q Do we review existing work the same way as new work in regard to
submittal requirements, service locations, grouping of mains, number of mains?
Yes, the only difference would be that on an existing building the service, etc.,
may have been installed under an older code. Did it meet code at the time it was
installed? For the most part these type projects must be examined on a case by
case basis.
2.
(Q) Which method of measuring clearance for ATS do we use? The method
described in NFPA 110 (7.2.2.1), or the method described in NEC 110-26a?
Both, we apply the method described in NFPA 110(7.2.2.1) and use the
measurement given NEC 110-26a.
3.
(Q) Do we accept 100% rating of breakers and equipment as per NEC
210.20a/215.3/230.42a(1)(2)/240.6, or require the designer to indicate on the
drawings and specifications?
Only if the designer gives the calculations to back it up. Otherwise he needs to
show that the equipment is rated for 100% of the connected load.
4.
(Q) Do we attach the oil filled transformer statement to the drawings we
review?
Commercial electrical plan examiners apply to the field and office set of drawings
the “Transformer Statement date 9/28/09” by way of a stamp, sticker, or
tape/paste copy. This includes all new projects and any existing building that
appears the service size will increase, or transformer be relocated. The Field
Inspector and the Chief, or Assistant Chief will resolve any location issues that
may arise on site.
Fourth Quarter 2009
5.
(Q) What stamps are electrical plans examiners required to affix to the
drawings?
When appropriate for the project:
a. Transformer sticker
–new buildings
-existing buildings with service upgrades
b. Selective Overcurrent Coordination Study
-all life safety
-all legal standby
-all hospital essential
c. Industrial Machinery
d. Listing and Labeling
e. Multifamily Residential
f. Examiners name & phone number
6.
(Q) How should a designer define repair garage for an electrical review when
the Building Code defines it different than the Electrical Code?
The electrical designer will need to show on the drawings based on NEC 511 the
hazardous classification for the building or portion of the building, if it is a major or
minor garage and specific details as to the function of the occupancy.
7.
(Q) How do electrical reviewers approach parking decks with multilevel fuel
dispensing and minor repair in regard to fire barriers (protection)?
The NEC does not address multilevel, however NFPA 30A allows only ground level
dispensing stations.
8.
(Q) Is the electrical designer required to show the available fault current from
the utility on the drawings if the voltage is 120/208/three phase?
Yes, unless the utility company is Duke Energy. It is the current policy of Duke Energy
to mitigate the available fault current to 10,000 amperes at a self-contained metering
point. Self-contained meter installations are those where the meter is connected directly
to the supply voltage and the meter is in series with the customer load(i.e., current and
voltage transformers aren’t used). The service voltage can determine where selfcontained metering may be used. For instance, 277/40V requires transformer rated
metering because of the voltage level. Typically 120/240V single phase, 120/208V
network, or 120/208V three phase is metered self-contained unless the load is
excessive. Other than that, voltage level does not affect the policy.
9.
(Q) Do we accept a feeder supplying multiple VAV boxes when the OCP is
located inside the equipment?
No, the OCP must be located in a disconnect remote from the equipment.
Fourth Quarter 2009