Nortek SH1BF4M1SP Series, Installation Instructions Manual

Page: 6 / 20

6
Thermostat
Red
White
Black
Air Handler
Outdoor
Heat
Pump
OUT
IN
R
W
C
O
Y
R
G
C
O
Y
O
C
R
W2
W2
Y1
IN
Green
G
W2
E
ODT
(Optional)
Figure 4. Thermostat Connections for
SH1BF4M1SP 2 - 4 Ton Units
Table 2. Thermostat Wire
THERMOSTAT
WIRE GAUGE
MAXIMUM RECOMMENDED
THERMOSTAT WIRE LENGTH (FT)
24 25
22 45
20 70
18 110
This unit must be electrically grounded in accordance with
local codes or, in the absence of local codes, with the National
Electrical Code (ANSI/NFPA 70) or the CSA C22.1 Electrical
Code. Use the grounding lug provided in the control box for
grounding the unit.
Thermostat / Low Voltage Connections
• Thermostat connections should be made in accordance
with the instructions supplied with the thermostat and the
indoor equipment. For typical installations with a heat pump
thermostat and air handler see Figure 4 and Figure 5 .
• The outdoor unit is designed to operate from a 24 VAC
Class II control circuit. The control circuit wiring must
comply with the current provisions of the NEC (ANSI/NFPA
70) and with applicable local codes having jurisdiction.
• The low voltage wires must be properly connected to
the units low voltage terminal block. Recommended wire
gauge and wire lengths for typical thermostat connections
are listed in Table 2 .
• The thermostat should be mounted about 5 feet above the
floor on an inside wall. DO NOT install the thermostat on
an outside wall or any other location where its operation
may be adversely affected by radiant heat from fireplaces,
sunlight, or lighting fixtures, and convective heat from
warm air registers or electrical appliances. Refer to the
thermostat manufacturer’s instruction sheet for detailed
mounting and installation information.
Outdoor Fan Motor
If the unit utilizes a 2-speed condenser fan motor, this motor
will operate on low speed when in low cooling, and on high
speed when in high cooling. A relay within the control area
switches the fan motor from low to high speed using the call
for high cooling as the trigger. Other models that utilize BLDC
fixed torque variable speed fan motors will not require a relay.
Transformer Upgrade Kit
If this 2-stage heat pump is installed in conjunction with a gas
furnace and fossil fuel kit, the furnace transformer MUST be
upgraded to one with a 60 VA rating or using the transformer
upgrade kit (904077). To upgrade the transformer:
• Remove the existing transformer and install the new 60
VA transformer.
• Remove the 3 amp fuse on the furnace control board and
install the 5 amp fuse provided.
NOTE: The new transformer may be larger than the existing
transformer that is mounted in the furnace. If this happens,
mount the 60 VA transformer using one of the mounting holes
in the furnace panel. On the other side either drill a 0.149
hole in the panel and use the existing fastener, or use a self-
drilling fastener to secure the other side of the transformer.
Figure 5. Thermostat Connections for
SH1BF4M2SX 5-Ton Units
G R W2 C E O Y1
Thermostat
OD
Stat
O Y1
R
C
Air Handler Heat Pump OD Section
W2
E
W2
W1
O
Y/Y2
G
R
C
Y2
Y2
W1 W3
Y1
NOTE: Jumper
W1 & W2 together
for shorter staging
time.
NOTE: Jumper
Y/Y2 & Y1
together for 2
Ton Units