Step 4 — Make Electrical Connections
Unit cabinet must have an uninterrupted, unbroken elec-
trical ground to minimize the possibility of personal in-
jury if an electrical fault should occur. This ground may
consist of electrical wire connected to unit ground lug
in control compartment, or conduit approved for elec-
trical ground when installed in accordance with NEC,
ANSI/NFPA (American National Standards Institute/
National Fire Protection Association) 70-1987 and lo-
cal electrical codes. Failure to follow this warning could
result in the installer being liable for personal injury of
others.
Unit failure as a result of operation on improper line
voltage or excessive phase imbalance constitutes abuse
and may cause damage to electrical components. Such
operation would invalidate any applicable Carrier
warranty.
POWER WIRING — Unit is factory wired for voltage shown
on nameplate. Provide adequate fused disconnect switch within
sight from unit, readily accessible, but out of reach of chil-
dren. Provision for locking switch open (off) is advisable to
prevent power from being turned on while unit is being ser-
viced. Disconnect switch, fuses, and field wiring must com-
ply with NEC and local code requirements. Use copper wire
only between disconnect switch and unit. Use minimum
60 C wire for field power connection.
Route power wires through opening in unit side panel and
connect in unit control box as shown on unit label diagram
and Fig. 6 and 7. Unit must be grounded.
CONTROL CIRCUIT WIRING — Control voltage is 24 v
(40 va minimum). See Fig. 7 and unit label diagram for field-
supplied wiring details. Route control wires through open-
ing in unit side panel to connection in unit control box.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (Ameri-
can Wire Gage) insulated wire (35 C minimum) For 50 to
75 ft, use no. 16 AWG insulated wire (35 C minimum). For
over 75 ft, use 14 AWG insulated wire (35 C minimum).
NOTE: Operation of unit on improper line voltage consti-
tutes abuse and could affect Carrier warranty. See Table 2.
Do not install unit in system where voltage may fluctuate
above or below permissible limits.
See Table 2 for recommended fuse sizes. When making
electrical connections, provide clearance at unit for refrig-
erant piping connections.
Use indoor unit transformer as 24-v (40-va minimum) sup-
ply for system or use accessory transformer.
Before performing service or maintenance, be sure in-
door unit main power switch is turned OFF and indoor
blower has stopped. Failure to do so may result in elec-
trical shock, or injury from rotating fan blades.
START-UP
Preliminary Checks
1. Check that all internal wiring connections are tight and
that all barriers, covers, and panels are in place.
2. Field electrical power source must agree with unit name-
plate rating.
3. All service valves must be open.
4. Belly-band crankcase heater must be tight on compressor
crankcase for those units with belly-band heaters.
Leak Test —
Field piping and fan coil must be leak tested
by pressure method described in Carrier Standard Service
Techniques Manual, Chapter 1, Section 1-6. Use R-22 at ap-
proximately 25 psig backed up with an inert gas to a total
pressure not to exceed 245 psig.
Before starting unit, crankcase heater must be on for
12 hours to be sure all refrigerant is out of the oil.
To energize crankcase heater, set space thermostat above
ambient temperature so there will be no demand for cooling.
Close field disconnect. The crankcase heater is now
energized.
Evacuate and Dehydrate —
Field piping and fan coil
must be evacuated and dehydrated by either of the methods
described in Carrier Standard Service Techniques Manual,
Chapter 1, Section 1-7.
Service valves must be fully backseated to close service
port. There is no Schrader valve at the service port, and
failure to backseat the valve could result in loss of sys-
tem charge or personal injury.
Charge System —
Release holding charge into system
by opening (backseating) liquid and suction line service valves.
Add charge amount as required for the total system. Refer to
indoor unit installation instructions for the required total sys-
tem charge, when connected by 25 ft of tubing.
LEGEND
NEC — National Electrical Code
TB
— Terminal Board
TB Connections
Field Wiring
Factory Wiring
Fig. 6 — Line Power Connections
6
