Step 9—Make Electrical Connections
To avoid personal injury or death, do not supply power to unit
with compressor terminal box cover removed.
Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within limits shown
on unit rating plate. Contact local power company for correction of
improper voltage. See unit rating plate for recommended circuit
protection device.
NOTE:
Operation of unit on improper line voltage constitutes
abuse and could affect unit reliability. See unit rating plate. Do not
install unit in system where voltage may fluctuate above or below
permissible limits.
NOTE:
Use copper wire only between disconnect switch and
unit.
NOTE:
Install branch circuit disconnect of adequate size per
NEC to handle unit starting current. Locate disconnect within sight
from and readily accessible from unit, per Section 440-14 of NEC.
ROUTE GROUND AND POWER WIRES
Remove access panel and control box cover to gain access to unit
wiring. Extend wires from disconnect through power wiring hole
provided and into unit control box.
The unit cabinet must have an uninterrupted or unbroken
ground to minimize personal injury if an electrical fault
should occur. The ground may consist of electrical wire or
metal conduit when installed in accordance with existing
electrical codes. Failure to follow this warning can result in an
electric shock, fire, or death.
CONNECT GROUND AND POWER WIRES
Connect ground wire to ground connection in control box for
safety. Connect power wiring to contactor as shown in Fig. 7.
CONNECT CONTROL WIRING
Route 24-v control wires through control wiring grommet and
connect leads to control wiring. (See Fig. 8–12.)
Use No. 18 AWG color-coded, insulated (35°C minimum) wire. If
thermostat is located more than 100 ft from unit, as measured
along the control voltage wires, use No. 16 AWG color-coded wire
to avoid excessive voltage drop.
All wiring must be NEC Class 1 and must be separated from
incoming power leads.
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Table 2—Accessory Usage
ACCESSORY
REQUIRED FOR
LOW-AMBIENT
APPLICATIONS
(BELOW 55°F)
REQUIRED FOR
LONG-LINE
APPLICATIONS*
(OVER 50 FT)
Crankcase Heater
Yes
Yes
Evaporator Freeze Thermostat
Yes
No
Accumulator
No
No
Compressor Start Assist
Capacitor and Relay
Yes
Yes
Low-Ambient Controller,
MotorMaster® Control,
or
Low-Ambient Pressure Switch
Yes
No
Wind Baffle
See Low-Ambient Instructions
No
Support Feet
Recommended
No
Liquid-Line Solenoid Valve
or
Hard Shutoff TXV
No
See Long-Line
Application
Guideline
Ball Bearing Fan Motor
Yes‡
No
* For tubing line sets between 50 and 175 ft, refer to Residential Split System Long-Line Application Guideline.
‡ Required for Low-Ambient Controller (full modulation feature) and MotorMaster Control only.
Fig. 6—Liquid Service Valve with Sweat Adapter
Tube
A94029
PISTON BODY
PISTON
PISTON RETAINER
SWEAT/FLARE ADAPTER
Fig. 7—Line Power Connections
A91056
DISCONNECT
PER N. E. C. AND/OR
LOCAL CODES
CONTACTOR
GROUND
LUG
FIELD GROUND
WIRING
FIELD POWER
WIRING
4
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