Carrier 38CKC Installation Instructions Manual page 4

DISCONNECT
PER N.E.C. AND/OR
LOCAL CODES
FIELD POWER
WIRING
3 PHASE ONLY
FIELD GROUND
WIRING
Fig. 3 --- Line Power Connections
Connect Control Wiring
Route 24v control wires through control wiring grommet and
connect leads to control wiring. (See Fig. 5.)
Use No. 18 AWG color coded, insulated (35_C minimum) wire. If
thermostat is located more than 100 ft (30.4 m) from unit, as
measured along the control voltage wires, use No. 16 AWG color
coded wire to avoid excessive voltage drop.
Use furnace transformer, fan coil transformer, or accessory
transformer for control power, 24v/40va minimum.
NOTE: Use of available 24v accessories may exceed the
minimum 40va power requirement. Determine total transformer
loading and increase the transformer capacity or split the load with
an accessory transformer as required.
COMPRESSOR CRANKCASE HEATER
A crankcase heater is required if refrigerant tubing is longer than
80 ft. (24.38 m).
When equipped with a crankcase heater, energize heater a
minimum of 24 hours before starting unit. To energize heater only,
set thermostat to OFF mode and close electrical disconnect to
outdoor unit.
INSTALL ELECTRICAL ACCESSORIES
Refer to individual instructions packaged with kits or accessories
when installing.
START- -UP
CAUTION
!
UNIT DAMAGE AND/OR PERSONAL INJURY
HAZARD
Failure to follow this caution may result in personal injury
and/or unit component damage.
Service valve gauge ports are equipped with Schrader
valves. Wear safety glasses and gloves when handling
refrigerant.
1. Fully open liquid and vapor service valves.
2. Unit is shipped with valve stem(s) front seated (closed) and
caps installed. Replace stem caps after system is opened to
refrigerant flow. Replace caps finger- -tight and tighten an
additional 1/12" with wrench.
3. Close electrical disconnects to energize system.
4. Set room thermostat at desired temperature. Be sure set
point is below indoor ambient temperature.
5. Set room thermostat to COOL and fan control to ON or
AUTO mode. Operate unit for 15 minutes. Check system- -
refrigerant charge. (See Check Charge.)
CONTACTOR
BLUE
GROUND
LUG
A94025
WARNING
!
PERSONAL INJURY and ENVIRONMENTAL
HAZARD
Failure to relieve system pressure could result in personal
injury and/or death.
1.Relieve pressure and recover all refrigerant before
servicing existing equipment, and before final unit
disposal. Use all service ports and open all flow- -control
devices, including solenoid valves.
2.Federal regulations require that you do not vent
refrigerant into the atmosphere. Recover during system
repair or final unit disposal.
SEQUENCE OF OPERATION
Turn on power to indoor and outdoor units. Transformer is
energized.
On a call for cooling, thermostat makes circuits R- -Y and R- -G.
Three phase models with scroll compressors, are equipped with a
phase monitor to detect if the incoming power is correctly phased
for compressor operation. (See Fig. 4 and Table 2.) If the phasing is
correct, circuit R- -Y energizes contactor, starting outdoor fan motor
and compressor circuit. R- -G energizes indoor unit blower relay,
starting indoor blower motor on high speed.
NOTE: If the phasing is incorrect, the contactor will not be
energized. To correct the phasing, interchange any two of the three
power connections on the field side.
When thermostat is satisfied, its contacts open, de- -energizing
contactor and blower relay. Compressor and motors stop.
If indoor unit is equipped with an off delay circuit, the indoor
blower can run an additional 120 sec to increase system efficiency.
Fig. 4 --- 3 Phase Monitor Control
Table 2—Phase- -Monitor LED Indicators
LED
OFF No call for compressor operation
FLASHING
ON
4
A00010
STATUS
Reversed phase
Normal