2
GENERAL INFORMATION
Codes
All electrical power wiring for the B3 series
electric furnace must be installed in accor-
dance with:
1) HUD Manufactured Home Construc-
tion and Safety Standard
2) NFPA 70 - National Electric Code
(NEC)
NOTE : Circuit breakers installed in the
B3 electric furnace are for short-circuit
protection of the internal wiring and to
serve as a unit disconnect. Circuit break-
ers installed in the B3BV electric furnace
DO NOT provide over-current protection
of the supply wiring. Over-current protec-
tion of the supply wiring must be provided
at the distribution panel and sized as shown
in the installation instructions or on the unit
data label, and per the NEC.
Location
Reference the installation instruction in-
cluded with this unit for location require-
ments.
Clearance
All electric heater kits less than 20 kw are
approved for use in air handler installa-
tions with zero-clearance to combustibles
at any blower speed. For horizontal and
upflow configuration, air handlers
equipped with 20 kw electric heater kits
are approved for installation with zero
clearance to combustibles at any blower
speed. When using a 20 kw electric heat
kit in a downflow installation, the blower
must be set for high speed for both heating
and cooling.
VENTILATION
The B3BV electric furnace has a cut-out on
each side for ventilation air. Use
NORDYNE part number 914120 or
914427 adaptor with Ventilaire III or IV to
supply the proper amount of ventilation
air. The VentilAire connections must be
made for the system to conform to H.U.D.
rules. Do not leave disconnected after
servicing or adding A/C to the system.
RETURN AIR
In closet or alcove installations provide at
least 235 square inches free opening for
return air for B-cabinet (19 3/4" wide)
models and 300 square inches for C-
cabinet (22 1/2" wide) models.
The return air opening can be located in a
closet door or a sidewall. If the return air
opening is directly adjacent to the side (or
front) of the air handler, 6" minimum clear-
ance must be provided between the side
of the furnace and the return air opening.
If no part of the return air opening is directly
adjacent to the unit no clearance is re-
quired.
If an upflow pedestal mounting stand is
fabricated in the field it must be constructed
strong enough to support the unit with all
accessories installed (approximately 130
lbs. for B-cabinet models and 200 lbs. for
C-cabinet models). The construction of
the pedestal stand must also allow for at
least 235 square inches free opening (300
square inches for C-cabinet models) in the
application. Field fabricated upflow ped-
estal mounting stands must be constructed
of noncombustible materials.
Refer to the installation instruction included
with this unit for other return air details.
SUPPLY AIR DUCTS
The duct system must be designed so that
the external static pressure of the system
does not exceed the maximum external
static pressure indicated on the unit data
label.
Downflow applications require the use of
a plenum connector shown in Figure 1 or
its equivalent if the supply air ducts pass
through the floor of the structure. See
Table 1 for plenum connectors available.
