22
441 01 2613 06
Specifications are subject to change without notice.
9. Electrical Wiring
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in
personal injury or death.
Turn OFF electrical power at fuse box or service
panel, lockout, and tag switch with a suitable
warning label before making any electrical
connections and ensure a proper ground connec-
tion is made before connecting line voltage.
!
WARNING
Power Supply Wiring
The furnace
MUST
be electrically wired and grounded in
accordance with local codes, or in the absence of local codes, with
the National Electrical Code (NEC), ANSI/NFPA 70
−
2008 in the
U.S., or the Canadian Electrical Code (CEC), CSA C22.1 in
Canada.
The power supply to the furnace connections must be between
104 VAC and 127 VAC during furnace operation for acceptable
performance.
Field wiring connections must be made inside the furnace
connection box. A suitable strain relief should be used at the point
the wires exit the furnace casing.
Copper conductors shall be used.
Line voltage wires should
conform to temperature limitation of 35
°
C rise. Wire and circuit
breaker sizing shall be based on the ampacity of the furnace
electrical components plus the amps for all installed accessories
(1.0 amps total for EAC and HUM). Ampacity can be determined
by using the NEC or CEC.
NOTE: Furnace will not have normal operation if line polarity is
reversed. Check ALL field and control connections prior to
operation.
Furnace must be installed so the electrical components are
protected from water and connected to its own separate circuit.
Junction Box (J-Box) Relocation
N8MPN/L Models
The J
−
box is installed in blower compartment on left side of casing.
An alternate J
−
Box location on right side can be used.
1. Remove bag containing two hole plugs and two self
−
tapping
screws from loose parts bag in blower compartment.
2. Remove and discard two screws holding J
−
Box to casing.
3. Move large hole plug from right to left J
−
Box location.
4. Move J
−
Box to alternate location and attach using two
self
−
tapping screws from bag.
5. Apply two hole plugs from bag at left J
−
Box location.
6. Position all wires away from sharp edges and moving parts.
Do not pinch J
−
Box wires or other wires when reinstalling
blower compartment door.
*8MPN/L Models
The J
−
Box is installed in the burner compartment on left side of
casing. An alternate J
−
Box location on right side can be used:
1. Remove and save two screws holding J
−
Box to casing.
2. Move large hole plug from right to left J
−
Box location.
3. Clip wire tie holding J
−
Box wires.
4. Move J
−
Box to alternate location and attach using two screws
removed from left side location.
5. Position all wires away from hot surfaces, sharp edges, and
moving parts. Do not pinch J
−
Box wires or other wires when
reinstalling burner compartment door.
Thermostat
Thermostat location has an important effect on the operation of the
furnace. Follow instructions included with thermostat for correct
mounting and wiring.
Low voltage connections to furnace must be made on terminal
board to furnace control. (See
Figure 19
)
If cooling is used, the
Y
from the thermostat must be connected to
the control board
Y
to energize cooling blower speed.
When using a nonelectronic thermostat, the thermostat heat
anticipator must be set to match the amp draw of the electrical
components in R
−
W circuit. Accurate amp draw readings can be
obtained at thermostat subbase terminals R and W. For an
electronic thermostat, set cycle rate for 3 cycles per hour.
Measure heat anticipator current in series from R to W at the
thermostat. If 24VAC humidifier is wired up to control, humidifier
must be energized. Allow furnace to operate for two minutes
before recording the AC amperage reading. Set anticipator on
thermostat to recorded value.
Optional Equipment
All wiring from furnace to optional equipment
MUST
conform to
local codes or, in the absence of local codes, the applicable
national codes. Install wiring in accordance with manufacturer’s
instructions.
Humidifier/Electronic Air Cleaner
The furnace is wired for 115 VAC humidifier and/or electronic air
cleaner connection.
!
REDUCED FURNACE LIFE HAZARD
Failure to follow this warning may result in reduced
furnace life.
Do NOT exceed 115V/1.0 amp. maximum current
load for both the EAC terminal and the HUM
terminal combined.
CAUTION
HUMIDIFIER
−
The 24VAC HUM is energized when the
pressure switch closes on a call for heat. The HUM (115VAC) is
energized when the inducer is energized.
ELECTRONIC AIR CLEANER
−
EAC is energized when there
is a blower speed call, except is NOT energized when blower
operates in the hard
−
wired continuous fan mode.
