4
• A properly sized branch circuit and disconnect switch must
be installed where it is easily accessible and within line of
sight of the outdoor unit.
• Remove the control panel cover. Route the power and ground
wires (3 wires, including earth ground) from the disconnect
box to the unit. Use of outdoor shielded conduit (metal
lined Sealtite
®
) is required. The electrical conduit opening
is located on the lower left corner of the control box.
• Connect the power wires to L1 and L2 box lugs of the
contactor, and the ground wire to the grounding lug to the
left of the contactor. See Figures 2 and 3. Only copper wires
should be used.
• Replace the control panel cover before applying power.
Control Circuit Wiring
The heat pump is designed to operate with a 24 VAC Class
II control circuit. Control circuit wiring must comply with the
latest version of the National Electrical Code (ANSI/NFPA
70) as supplemented by local building codes.
In general, 24 VAC control power and communication bus
wiring must be run to interconnect the thermostat/controller,
the indoor unit, and the outdoor unit. The “hub” of this network
and source of the 24 VAC is located within the indoor unit (air
handler or furnace). Refer to iQ Drive System Field Wiring
Instructions, NORDYNE document 709031 shipped with the
controller, for connection of control wires to the indoor unit
and for description of other indoor fi eld wiring, including to
the controller.
Five (5) wires must be run between the indoor unit and the
outdoor unit (2 for 24 VAC power and 3 for communications).
Use one shielded cable (3 or more conductors) for
communications only, and a separate cable or pair of wires
for control power. Refer to wiring diagram Figure 4 and Table
II.
1. Pass the 5 control wires into the hole in the lower right side
of the control panel of the outdoor unit, into the separate
low voltage wiring compartment. See Figures 5 and 6.
2. Locate the 5 corresponding factory-wired leads with
stripped ends. Assure that each of these 5 wires (on the
factory wiring side of the wire connections) loops around
and through the “donut” (toroidal choke). Refer to Figure
7 which shows one wire making a single loop.
3. Connect each of the 5 fi eld-run wires to its factory-wired
counterpart using a wire nut, as indicated in Figures 4, 5
and 6.
4. Replace the control panel cover before applying power.
IMPORTANT
It is critical that the wires meant to connect to 24
vac control power (RED & GRAY) are not mistakenly
connected to the communication bus wires (YEL,
WHT, GRN). 24 volts applied to the communication
bus will damage the equipment.
Communication Wiring
Indoor
Interface
Board
Terminal
Indoor
Interface
Board plug
wire color
Outdoor unit
wire color
Outdoor Interface
Board Terminal
(RHS circuit
board)
DX+
YEL
YEL
3 pin 3 wire white
connector plug at
RHS circuit board
terminal
“INDOOR”
DX-
WHT
WHT
GND
GRN
GRN
Control Power Wiring
R (screw)
[no factory
wire]
RED
“R” terminal screw
C (screw)
[no factory
wire]
GRY
(contactor coil,
RHS)
Table 2. Control Wiring to Outdoor iQ Heat Pump Unit
iQ Zone Control Wiring
For iQ Zone systems, fi eld wiring is required to connect the
Airzone control board to the iQ communication bus and to
provide a ground connection for the separate zoning control
and communication network. Refer to the iQ Field Wiring
Instruction document provided in the iQ controller kit for more
details. A 3-wire cable must be run from a splice point in the
iQ communication bus to the one 3-pin connector on the
Airzone control board.
Recheck Wiring
Check that wire routing is correct and connections are secure
for all power and control wiring.
REFRIGERANT LINE CONNECTIONS
Line Design and Routing
Refrigerant lines must be connected by a licensed EPA
certifi ed technician following sound established installation
practice. Once the heat pump location has been determined
and the unit set in place the refrigerant lines should be routed
and connected.
• Refrigerant lines should follow a direct path from the indoor
coil to the outdoor unit avoiding sharp bends. When lines
pass through walls, make sure to properly seal and support
them so that vibration is not transmitted to the structure.
• Refrigerant tubing should be supported in a manner which
assures that the tubing will not vibrate or wear as a result
of contact with sharp materials or edges during system
operation.
• Lines must be clean refrigeration-grade copper.
• Avoid removing caps and plugs from the heat pump or lines
until they are ready to be connected.
• Insulate the vapor line with refrigerant line insulation ¼” wall
thickness or greater.
Proper system performance and oil management depend on
properly selecting the liquid and vapor line sizes. Refer to Table
III for the proper size of fi eld supplied lines. The maximum
allowable refrigerant line length is 100 ft.