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3.13.7 ELECTRIC HEATER KIT SUPPLEMENTAL INFORMATION
Heater Kit Supplemental Information:
What allows the manufacturer to use standard Circuit Breakers
up to 60 amps inside the air handler, when using an approved Heater Kit?
National Electric Code (Section 424-22b) and UL standards allow subdividing heating element
circuits, of less than 48 amps, using breakers of not more than 60 amps. Additionally per NEC 424-3b, a rat-
ing not less than 125 percent of the load and NEC 424-22c, which describes the supplementary overcurrent
protection required to be factory-installed within, or on the heater. The breakers in the heater kit are not, and
have never been intended to protect power wiring leading to the air handler unit. The breakers in the heating
kit are for short circuit protection and to provide a disconnect. All internal unit wiring, where the breakers
apply, has been UL approved for short circuit protection.
Ampacity, (not breaker size), determines supply circuit wire size. The ampacity listed on the unit rating plate
and the Maximum and Minimum circuit breaker size (noted above) or in the units specification sheet or
installation instructions provides the information to properly select wire and circuit breaker/protector size.
The National Electric Code (NEC) specifies that the supply or branch circuit must be protected at the source.
These are the
required maxi-
mum and mini-
mum circuit
breaker sizes
for overcurrent
protection and
should not be
confused with
the size of the
breakers
installed in the
heater kit.
Contractor
should “mark
or check” the
left column for
the kit installed.
If a heater
kit is listed
both
Single
and Multi-
circuit, the
kit is
shipped
as a Multi-
circuit and
will
require a
single
point kit.
Only listed kits can be applied
MARK HEATER INSTALLED/
L’APPAREIL DE CHAUFFAGE DE MARQUE A INSTALLE
(-)HLA-HM4821JA
AIR CONDITIONING DIVISION
