Anyone who has served on an NEC code-making panel or a standards development
organization’s advisory committee, knows how
intertwined these two endeavors are. Simply being a user
of the NEC or any third party product standard,
one sees that the interrelationship between a product
standard and the applicable installation code is
paramount to safety and well-known. However, the
process whereby one standard can influence the other can
often be fuzzy and downright confusing. This
article will examine by example several recent
interactions between installation code and product
standards.
It is appropriate for standards to
influence one another; however, many NEC code-making panels routinely reject proposals reasoning
that certain requirements belong in product standards,
while other panels include broad requirements that
hopefully act as a catalyst to SDOs. It is this
author’s opinion that broad product requirements (and
some specific ones) do indeed belong in the NEC providing the impetus for the standards development
process. However, the full set of specific
product requirements are indeed the purview of product
standards. As such, should the rules be changed
to disallow the "end product standard"
rejection reason? This author thinks so. Perhaps
these examples provide insight leading to consideration. After all, in the end, it’s about electrical
safety; where the rule resides and who gets to publish
it are just bookkeeping.
Hair Dryers and Immersion Detection
Presently, NEC 422.41 requires
that cord- and plug-connected freestanding hydromassage
units and hand-held hair dryers contain protection
should those products become immersed. It further
states that the requirement is with the product in the
"on" or "off" position. This
seems like an odd requirement for the NEC;
however, the history will explain much.
One might question the need for this
requirement since bathroom receptacles are required to
be protected by ground-fault circuit interrupters (GFCIs).
The GFCI requirement has been in the NEC since
1975. Thankfully the current requirement
rightfully considers older buildings without such GFCI
provision. By requiring the protective device on
the hair dryer, one is assured that protection is
available, even in older homes.
According to Consumer Products Safety
Commission hazard data referenced in the 1989 technical
committee documents [(TCD), now called the report on
comments (ROC)], fifteen to twenty electrocutions per
year were reported since 1977. These
electrocutions were reported as a result of hand-held
hair dryers falling into occupied bathtubs. Considerable
discussion took place as well as the realization of the
obvious need for some sort of protective device on
appliances subjected to immersion.
In September of 1988, the seventh
edition of UL 859 included an exposure to water test,
which was to be effective April 1, 1990. This
test checked for leakage current in a metal tub
containing very conductive water. The results
were considered acceptable if the leakage current was
less then 5 milliamperes. However, the test
description included the following sentence, "Any
on-off switch provided is to remain in the off position
during the test." This seemed very curious. I
guess the date of April 1st may have had some
significance.
This test requirement led to some
hair dryer manufacturers installing so-called
"waterproof" switches in hand-held hair dryers. This insulated any live parts from contacting the
water provided the switch was in the off position. Obviously,
there was no protection when the hair dryer was turned
on.
Since the safety hazard still
existed, an NEC proposal was submitted and
recorded in the 1989 TCR (now called the ROP). This
proposal called for immersion protection with the switch
in the "on" or the "off" position. The proposal was accepted by a 9 to 1 vote. Later
in the 1989 TCD, the CPSC made a public comment
recommending the acceptance of the proposal. The
proposal was subsequently unanimously accepted, during
the comment stage.
The first Code requirements
came in NEC–1990, under 422-24, whereby
protection for personnel was required for hair dryers
and hydro-massage units. This requirement did not
specify any particular technology nor any specific test. It simply specified personnel protection be built
into the products, and function in the "on" or
the "off" position of the switch.
UL 859, dated January 25, 1990, was
modified to require hair dryers that incorporated
immersion detectors be required to trip when immersed
regardless of the switch position. Later, the
January 11, 1991, requirement for hair dryer immersion
protection maintained the upgraded requirement for
immersion protection in both the on and off condition
and further began to mention protective devices like
GFCIs and immersion dectection circuit interrupters (IDCIs). Some time later, ALCIs were also utilized.
In this example, the product
requirement came first. However the obvious
deficiency in the requirement necessitated the NEC proposal, which some may say was needed to nudge the
product standard further. So in this case the egg
became a chicken which hatched yet another egg.
High Pressure Washers and
GFCI Protection
The present NEC 422.49
requires all single-phase, cord- and plug-connected
high-pressure washers rated 250 volts or less, to
incorporate a GFCI within 300 mm (12 in.) of the plug
cap. This offers protection to the length of cord
(which can be considerable) as well as the pressure
washer since the requirement mentions GFCI protection at
personnel protection levels (0.005A). This
requirement first appeared in NEC–1990 as
422-8(d)(3). The GFCI was required in the cord
just as the present requirement. However, an
exception existed which negated the GFCI requirement (in
the supply cord) as long as the pressure washer was
rated at over 125 V, double insulated and contained a
warning tag indicating that the pressure washer must be
plugged into a GFCI-protected receptacle.
NEC–1993 added two more
exceptions and modified the original one. The
original exception was modified to eliminate the 125-V
rule. Section 422-8(d)(3) exception #2 was added
which exempted 3-phase pressure washers, and exception
#3 also exempted washers rated over 250 V. These
changes were initiated by a panel proposal logged in as
20-15. It is interesting to note that the
inclusion of a safety device or the type of insulation
system is usually a product standard issue; but here,
the panel had no problem including product standard
rules within the body of the NEC. Of additional
significance is that during the comment stage (20-12),
Mr. Bernardo opined that the proposal (three exceptions)
should be rejected as the rule would be unenforceable
and that it more properly belongs in the product
standard. The panel statement read, "CMP20
continues to believe this section of the Code is
necessary to recognize known and demonstrated advances
in technology." My, my! Do not product standards
also have the ability to recognize advances in
technology as well?
If that was not enough, NEC–1996
changed the exceptions once again. This Code continued the GFCI rule in 422-8(d)(3) and maintained
the exceptions for 3-phase and units rated over 250 V. It also eliminated the exception for double
insulation accompanied by a warning tag.
It is interesting to note that
proposals to eliminate the double insulation exception
(20-7 and 20-17) were both rejected. The panel
statement included the comment which was in favor of
continuing with the exception for double insulation. The
panel opined, "The exception recognizes the added
safety of double insulated spray washers by allowing the
GFCI to be located remote from the unit. This
would discourage the manufacture of double insulated
units." These two extracted sentences speak volumes
about the influence that the Code has on product
standards. Take a second look at the words. "This
would discourage the manufacture of double insulated
spray washers." Here we find not only end-product
standard requirements, but purposeful influence being
applied to a product’s standard and its design. Good
arguments were made indicating expected ambivalence
toward a warning label and the inappropriateness of
allowing double insulation as an alternative to GFCI
protection, especially in a wet environment. In
the comment stage, exception #3 was eliminated. Of
course the product standard followed suit and
incorporated these requirements. So in this case,
like the previous example, the egg came first, went
through a few DNA replications, and then, in the end,
became a chicken.
Recessed Fixtures and Thermal
Protection
The next example is similar in
history and consequence. It goes like this:
During the late 1970s and early 1980s, many homeowners
were insulating their homes due to spiraling energy
costs. Many had "blown-in" insulation
installed in their attics. While the insulative
properties of this material were admirable, the
fire-retardant properties were lacking. This led
to fires which were blamed on recessed lighting fixtures
(hi hats). During that period it was politically
correct to call a fixture, well, a fixture. Upon
further investigation, it was determined that the
blown-in insulation may not have been installed
correctly. This amounted to the fixtures being
buried in the insulation. These fixtures were not
listed for direct burial in insulation and many were
marked, cautioning to keep insulation away from the
fixture. It is surmised that these warnings were
not heeded.
The present Code requires in
410.65(C) that recessed incandescent fixtures
incorporate thermal protection. There are some
special exceptions and rules where specially designed or
installed recessed fixtures are not required to be
thermally protected. For the most part,
residential types are also required to be thermally
protected. The UL standard has a complete test
program that tests for the thermal protector’s ability
to trip when buried in insulation and, also, not trip
when installed in a tight, but un-insulated ceiling.
This rule first appeared in NEC–1981
with the special effective date of April 1, 1982. This,
in effect, gave an additional year and one-half for
fixture manufacturers to design and certify their
thermally protected fixture. Of course, UL
developed specific requirements which were, in turn,
included in their fixture standard. I chose this
example as it once again illustrates that the egg
precedes the chicken, and, more importantly, points out
a very useful tool. Namely, the delayed
implementation date. This is an excellent tool
that can be used by NEC panels when a proposal is
appropriate and becomes a rule, but industry and product
certifiers may not be quite ready to supply and certify
products. Again, the egg surely precedes the
chicken, but this important tool allows for a longer
gestation period.
The Other Side of the Coin
One example mystifies and confounds
even the most scholarly of Code experts. Consider
the rules of 210.21(B)(2) and 210.23(A)(1) to which
collectively many people refer to as the 80 percent rule. These rules are clear in addressing cord- and
plug-connected loads supplied by a receptacle. The
rule states in table 210.21(B)(2) that the maximum cord-
and-plug-connected load on a 15-ampere branch circuit
shall not exceed 12 amperes. Section 210.23(A)(1)
goes further and states that the rating of any
single cord- and plug-connected utilization equipment
shall not exceed 80 percent of the branch circuit rating. Sounds clear enough. Maybe not. Consider
a 1500-W hand-held hair dryer rated 125 V. This
dryer theoretically draws 12 amperes. All is
well, Code rule is satisfied and everyone can
sleep. Enter the 1850-watt hand-held hair dryer. At 125 V this theoretically draws 14.8 amperes. How
can these products achieve a listing and be used on a
15-ampere branch circuit? Also, how can they be rated at
1850 watts with a 15-amp plug cap? The Code rules
seem clear enough. No product standard to deal
with? Or is there?
UL 859, the standard that covers
hand-held hair dryers, permits listing of 1850-watt
hand-held hair dryers with 15-amp plug caps. How?
Many theories exist on how this has been allowed to
happen. This author has spoken to a few folks
involved with the process and it comes up the same each
time. "I don’t know." If
you really want a flavor for just how absurd this has
become, take a look at proposals 2-189 and 2-190 where
the panel statement seems real clear, yet the product
standards remain the same and allow listings of
1850-watt products with a 15-amp plug cap. In
this case, there was an egg, a clearly identified egg,
but this particular egg was never sat on by a hen and
never became a chicken.
Air Conditioners and Arcing
Protection
There is another case worth noting. Section 440.65 of NEC–2002 requires room
air conditioners to incorporate AFCIs or LCDIs in their
power cord or in the plug cap. Pretty straight
forward, yet this past summer I purchased an 8000-BTU
room air conditioner that was manufactured in 2002 and
it did not have one of these safety devices. How
is this?
To the best of my ability to
ascertain, the product standard has not yet incorporated
the requirement that became Code on January 1,
2002. The UL standards making panel responsible
for the air conditioner standard had voted to, in fact,
include such requirements, yet the requirement has not
been implemented as of this writing. Further
confounding the issue is the statement in the standard
that speaks of being in league with the NEC. In
this case, once again, a very clear and identifiable egg
appeared, but, alas, once again, no hen. Rather,
a nasty old fox was seen near the egg and nary a hen to
be found.
Conclusion
Many more examples could be
researched, but the outcome would be the same. Simply,
the NEC is full of product requirements and
should continue to include requirements. It is
appropriate that an NEC rule migrates into the
product standard, and, in turn, makes specific product
requirements that are in league with the Code rule. This is a self-checking method for
increasing product safety and should be continued. Consider
a product that does not obtain an NRTL listing. This
is permitted in our system. So, then, the product
standard would not apply—but the Code does. So
by having product specific rules in the Code,
when appropriate, this often overlooked loophole can be
closed when safety concerns rise to a level meritorious
enough for a Code rule.
It is this author’s opinion that
the NEC rules which each panel follows should be
amended to prohibit automatic rejection of proposals
along with panel statements that claim the rule belongs
in the product standard. To further close the
safety gap, product standards that purport to be in
agreement with the NEC, should be required to
adopt the Code rules upon publication. After
all, the Code process is transparent and
available to everyone long before the Code’s ultimate effective date.
Steve Campolo is presently employed
by Leviton Manufacturing Company Inc., and is vice
president, engineering–personnel protection products.
He is not now and never has been a chicken farmer nor in
any way associated with raising chickens. He has been
with Leviton over 22 years. He has prior experience at
Underwriters Laboratories, Dayton T. Brown Laboratories
and others. His education includes a master’s degree
from Long Island University, a bachelor’s degree from
New York Institute of Technology and an associate’s
degree from Suffolk County Community College. Mr.
Campolo served on code-making panel 17 for two and
one-half cycles. He also serves on the UL Industry
Advisory Group for transient voltage surge suppressers,
flexible cords, appliance leakage circuit interrupters,
electronic controls, arc-fault circuit interrupters,
ground-fault circuit interrupters and others. He is also
chairman of the NEMA Technical Committee for flexible
cords. |
