This is a question many inspection
departments ask as budgets for governmental agencies are
scrutinized and cut back. It is the field inspector that has
the visibility to the customer, so this is where the priority
also seems to be set. Just recently I was at a meeting with
other inspection jurisdictions in the area and one is having
some personnel changes and where do they cut at this time?
Plan review. The state rules in my area require electrical
plan review only for health care, education, and prisons. It
leaves the entire inspection process to the field inspector
for large commercial and industrial projects.
In my last eight years of doing electrical
plan review, it has been amazing the number of code violations
I find daily. Many of these violations are items I would have
overlooked when I was doing field inspections. Electrical
systems seem to be getting more and more complex with the use
of computerized control systems and complex alternate power
systems. I really do not know how a field inspector running
from project to project could ever do a really complete
inspection without the aid of the plan review tool.
Who benefits from
an electrical plan review?
Plan review benefits many: the field inspectors, the
designer/engineer, and the end user customer. A plan review
should first of all create a tool for the field inspector, in
order for a thorough inspection to be made. It should also
reduce the time spent in the field inspection process because
many issues have been looked at ahead of time. The
designer/engineer may receive some of the biggest payoffs.
Finding missing or wrong equipment on paper is much easier
than finding problems in the field, after it is installed.
Imagine a new 1200-amp switchboard with 6 mains being
installed when it is required to have a main breaker or no
second level of ground-fault protection in a switchboard in a
health care facility. These can be very major repairs after
installed but if caught during plan review, it just requires
the right equipment ordered in the first place. The end user
will have a finished project that is less likely to have any
code violations when this extra process is added to the
inspections.
Does the NEC address
electrical plan review?
In the 2002 NEC, Article 80 was added and in the 2005
this has moved to annex G. This section lays out how to set up
an electrical inspection program, and plan review is spelled
out as a part that can be used. Also, Section 215.5 Feeder
Diagrams is basically the outline for needed documents used in
plan review.
Who should do the
plan review?
Both of the inspection agencies I have worked for and most of
the others in the area have an electrical plan review staff,
which has this specific task. I really see pluses and
negatives for this system. The plus is, once the staff is
trained and has the system down, the process becomes much more
thorough and much quicker. The negative is, having done plan
review I believe I am now a much better field inspector and
really have a better understanding of items that need to be
looked at much closer. I would have to say that if an
individual has the skills and time to do both, starting with
the plan review and then doing the field inspections on the
same job could be the best option.
Should the
reviewer have engineering experience?
Having worked in an engineering office and then working as a
wireman and inspector, I believe that someone with hands-on
field experience would probably have better Code perspective. Most of the engineers are very good at knowing
how to make the system work but sometimes overlook the code
violations that a full-time student of the Code will
catch.
The process of a plan review will vary from
person to person just as the inspection of a single-family
residence varies. The first thing I do when receiving a new
plan is to log it into a database, assigning it a number and a
place in line for review. A quick screening or run-though is
done to make sure all the needed information is included with
the submittal. If not, two options are available: one, to just
reject the plans and send them back; the other is to ask via
fax or email for the information needed. You notice I
recommend fax or email. I really try to use these written
medias rather than just phone calls, because this way both
your correspondence and the engineer/designer’s
correspondence are in writing and you can file it for future
reference. A good filing system with these correspondences and
other information is very important when issues arise in the
field or at a later date.
When a plan comes up for the review process
then the putting of the pieces together really begins. The
plans on many projects are like a puzzle that needs to be
aligned in order to understand the system. Many questions must
be asked and answers searched out. I will spend some time with
sticky notes or a note pad just thumbing through the sheets
and making notes just to understand the scope, find schedules,
and any other information that is needed in the review
process. I may make tabs with post-its for the sheets with
information that will be referenced through the process. I
also normally photocopy the panel schedules and lighting
schedule input volt-amps so these can be referenced while
working on the plan sheets.
What is the
facility?
The next question asked is, Is it a commercial building,
residential, industrial, healthcare, and does it have a place
of assembly? Do the units of an assisted living facility meet
the requirements of a dwelling unit? These and many other
questions must be answered in order to know what direction and
requirements apply. In recent code cycles, the construction
type has become important in order to know if NM cables can be
used. Many of these questions are important for the review
but, also, as equally important to note for the field
inspector.
Where is it
located?
Another one of the big questions that must be answered is
where is the location of the service point as defined in NEC 100? This is where the review must start and NEC requirements followed. In the area I have been working, more
and more we are seeing the service point out at some primary
voltage metering point and the customer owning the primary
distribution system on the site. Now this primary system must
meet NEC requirements rather than utility standards.
This can create many problems with service disconnects,
transformer secondary conductor protection (240.21), and
grounding.
What is the main
review process?
After I have the scope somewhat hammered out, then comes the
main review process. I spend time verifying loads from the
plan sheets to the panel schedules. This will vary from
project to project and will normally depend on what is found
as to the detail. I do a few random checks of outlet and
lighting counts on each plan. If things check out, then I may
move on. If I start finding inaccuracies, then more time must
be spent. The personal system I use is to use different
colored highlight pens for the different load types on the
panel schedule. This really speeds up the load calculation
process. I may also at this time look at the designer’s load
calculations for the service and feeders. If these have extra
capacity, then branch circuits load verification may not be so
critical. On the other hand, I have had projects where the NEC calculated load is within amps of the service capacity. Some
designers push these to the limit because they figure they can
just use meter demand calculations after the project is up and
running for future expansion. On projects like these I may
have to verify each and every circuit in order to make sure no
errors have been made.
The random check of branch-circuit loads
seems to work fine for receptacles and lighting; but when it
comes to HVAC, kitchen equipment, and motor loads, I normally
check all of these to the panel schedule loads. Just one or
two missed or incorrect loads of larger equipment can really
cause problems with distribution system equipment sizing. I
also always verify all loads installed on panels fed from
emergency power sources. These are so critical and misplaced
loads seem to be common on these panel schedules.
During the branch circuit verification
stage, other items come to light. Hazardous (classified)
locations may be spotted by the types of equipment being
serviced. If so, I will then ask for the documentation that is
required by NEC 500.4(A). This documentation will then
become part of the approved set of plans for the field
inspector’s use.
Other issues that can be looked at—such
as outlet spacing, required number of outlets for health care
facilities, and other circuit types of items—can all be part
of this circuit verification process.
If it is health care facility, many other
questions must be answered. Does it have critical care areas,
where are the patient care areas, are there wet locations, is
it a hospital, nursing home, or other health care facility?
These types of facilities really require close scrutiny, as
many extra requirements are needed for safety of the occupants
during a power outage and the possibility of electrocution
during procedures. Items that must be checked include: number
of outlets, grounding, ground-fault protection, emergency and
standby systems.
All facilities with emergency power systems
must also be looked over much more carefully. What loads are
on which branch of the backup system, and how many transfer
switches have been installed? Are the NEC 700 emergency
systems run in their own raceway system and not intermixed
with other wiring systems? Are battery emergency lights on the
normal lighting circuits for the area served? Does the system
require load shedding? These are all common areas of
corrections found during the plan review process.
How are load
calculations handled?
Once I have panel schedules that I feel are accurate, I then
move on to the load calculation portion of the review. A plan
reviewer must know Article 220 inside and out. I normally just
do my own calculations on how I see the system, using the
color code from the load verification process to plug the
loads into the correct categories. I use a spreadsheet program
for this process but these can also be done by hand. Once I
have completed my calculations then I will look at the
designer’s loads. Many times we may have items a bit
different, but a lot of the time the calculated load is very
close. If I find major discrepancies, then the search begins
for why. One of the major errors I find is designers not
carrying the categories through downstream in the distribution
system and using only the connected loads or even having
entire panels dropped in calculations. Another common error is
applying code diversity multiple times on the same loads at
different parts of the distribution system.
Much care must be taken when the designer
uses metered demand calculations as allowed by NEC 220.87. I find many designers that attempt to subtract
connected load removed during remodel from a meter demand
calculation. The only way this could even be considered as
valid is if the loads could be verified at full load during
the metered peak (this normally cannot be verified). Other
things that need to be considered with a 30-day demand reading
are heating and cooling loads and occupancy of the facility at
time of peak demand. It seems each year I do school portable
classroom reviews and designers submit metered demand records
during summer months with no students in class.
Why is the
one-line diagram important?
Once I have load calculations competed then I move on to the
one-line diagram. This is probably the one most important
document for both the plan reviewer and the field inspector.
Because of the importance, I build a worksheet that goes
through the entire distribution service and feeder system.
Each service or feeder has a separate line in my worksheet
and, when completed, gives the inspector an easy-to-carry 8 ½
x 11 package to use in the field. This is also my tool to
verify each feeder for loading, sizing of overcurrent
protection, conductor sizing and equipment sizes. Each feeder
has the starting equipment or panel, ending equipment or
panel, voltage, phase, starting overcurrent protection, ending
overcurrent protection, phase conductor size, phase conductor
ampacity, connected load, calculated load, metered demand load
(if used), calculated amps, and any special notes or
calculations (see figure
1). With each line, overloads can be caught quite easily
and transformer protection can be verified. I have laminated
tables for transformer protection, motor loads in VA per
horsepower, conductor ampacities, and conversion multipliers
for converting from kVA to amps for all voltage and phase
levels, all on the wall in front of my desk, that really help
with these verifications.
Other things that can be looked at on the
one-line are grounding, building disconnects, ground-fault
protection of equipment, and fault current levels at different
levels of distribution system. Many of the parts of plan
review are limited to what can be seen on a piece of paper and
field inspection still must verify a code-compliant
installation. Just because a plan is stamped approved does not
mean the Code does not need to be followed. One example
is the distance of secondary conductors on a step down
transformer. The plan may show a short distance that would
fall within the 15´ requirement but if the conduit routing
was not a straight line then this would not be met. So plan
review is definitely not a replacement to a good field
inspection; it is only a tool to supplement the inspection.
When the plans have been reviewed and all
error corrections have been received from the designer and
incorporated into the plans, then they can be stamped
approved. These approved plans are then sent to the job site
for the use of both the installer of the system and the field
inspector during the duration of construction. The department
I work for does not keep records of the plans, but as
mentioned before, a file is kept for each review. This file
would include all correspondence during the review process, my
load calculations, a copy of the worksheet for the
distribution system, and the approval letter. With this
information most issues that arise in the future can be
addressed. The files also become quite useful when doing
future reviews of remodels on the same facility to see if
plans are accurate with loads and how distribution system is
shown. The only plans I keep in our office are one-line
diagrams of systems like hospitals and school campuses that
are complicated and have frequent projects and remodels.
So is plan review really needed? Yes, I
would say it is a vital part of the inspection process and
without some type of review a complete inspection really
cannot take place.
Bruce Reynolds is the electrical plan
reviewer and inspector training coordinator for the city
of Tacoma (Tacoma Power) inspection program. Reynolds
was formerly employed by the state of Washington as a
field inspector, plans examiner, and supervisor of the
electrical plan review program. He holds a state of
Washington master wireman license and is journeyman
wireman in IBEW local 76. He also holds all IAEI
certifications. He is one of the trainers for the Puget
Sound Chapter of IAEI for CEU classes. |
