NFPA Journal - July/August 2020 - 38

In Compliance
intensity from notification appliances
could cause confusion and impede
egress. There may be design or operational conditions that could warrant
the installation of notification appliances in exit passageways and stair
enclosures, but a careful analysis is
necessary to avoid impeding exiting
from the building.
It is never necessary to install notification appliances in an elevator-in
fact, the code does not allow the evacuation signal to operate in elevator
cars. Should an alarm occur, one of
two things will happen. First, the
doors will open, and the occupants
will hear the alarm. Second, if there is
smoke detected in an elevator lobby
or mechanical room, the elevators will
automatically be recalled to a safe floor.
The occupants of the elevator will have
no opportunity to change the operation, and having the alarm sound in the
elevator would not assist them.
The same is true for visible signals,
which are not required in elevator cars,
exit stair enclosures, or exit passageways, for many of the same reasons we
do not require audible notification in
these spaces. Ultimately the goal is to
ensure the notification appliances operate when and where they are needed.
Wayne D. Moore is vice president at Jensen
Hughes. NFPA members and AHJs can use the
Technical Questions tab to post queries on NFPA 72
at nfpa.org/72.

NFPA 70 + 70E

Electrical Safety

Electric vehicles and
marinas in the 2020 NEC
By Derek Vigstol
hile the 2020 edition of
NFPA 70®, National
Electrical Code®, was
published last fall, July
tends to be when states
shift to the latest edition. This delay
between when the code was published
and when it is actually implemented

W

gives jurisdictions time to sort through
what's new and what's changed, and to
consider how the new edition of the
code might affect them. Whether jurisdictions use the NEC as is, or whether
they apply local amendments to the
code, a thorough understanding of the
revisions will help all users better
comply with the ever-changing electrical landscape.
Two important areas that were
subject to changes in the latest NEC
were electric vehicles (EVs), as well as
marinas and boatyards. Both of these
topics have generated a great deal of
activity in recent years, and the most
recent changes reflect the efforts of
both the code and the broader electrical community to remain as current
as possible in how they address these
rapidly evolving areas.
EVs have undergone-and continue
to experience-a particularly rapid
evolution over the past few years.
From new battery chemistries that
allow longer distances on a single
charge, to using the battery in the
vehicle to feed power back into a
building, these technological advancements require the installation rules
to adjust accordingly. The 2020 NEC
includes a few revisions that users
should be aware of when it comes to
these systems.
Most notably, the code making
panels of the NEC dealt with how to
handle the EV supply equipment, or
EVSE, that is bidirectional-equipment
known in the industry as electric vehicle power export equipment, or EVPE.
New systems are becoming available that can charge the vehicle under
normal use and can also use the car
to supply power to a building, such
as a home or office, when the power
is out, essentially turning these vehicles into energy storage equipment.
New requirements in Article 625 cover
things like GFCI protection for receptacles, supply cable requirements, and
ratings for equipment.
Similarly, marinas, boatyards, and
other facilities that utilize electricity on or near bodies of water have
received a lot of attention recently
from the electrical safety community.

Unfortunately, this attention has
resulted from multiple tragic events
involving electric shock drownings
(ESD). The evolution of the requirements around these areas has been
taking place for a while, but for the
2020 NEC many of these requirements
were adjusted.
One issue that was addressed was
how the 2017 edition of the code
required ground-fault protection that
would trip at a maximum of 30mA
total for the system. But docked
vessels can "leak" current into the
water, and situations arose where only
a few vessels that were connected to
electrical power in a marina could
cause the protection to trip. This
prompted marina owners to remove
the ground-fault protection devices.
Referencing multiple studies on
the topic of stray current entering the
water, the code making panel looked
at the amount of current that is likely
to result in ESD-the panel determined that most vessels will have
some amount of leakage current, but
that most of those are low enough not
to cause ESD. The panel further determined that shore power receptacles
must be protected at the 30 mA level,
while the feeder must be protected
at a level not to exceed 100 mA. This
adjustment will allow multiple vessels
to be connected to shore power without tripping ground-fault protection
devices, and will ideally eliminate any
cause for marina owners to remove
these life-saving devices.
There are many other changes to
the 2020 NEC that could affect electrical installations in your jurisdiction.
As the code is implemented in your
region, understanding those changes,
why they were made, and their potential impact will help you better apply
the code's requirements. The NEC
exists to protect us from electrical
hazards; proper installation is where
it all starts, but the NEC can only
achieve its goals when the requirements are applied as intended.
Derek Vigstol is an NFPA technical lead, Electrical
Tech Services. NFPA members and AHJs can use the
Technical Questions tab to post queries on NFPA 70
at nfpa.org/70next.

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