Carrier 38HD018 - START-UP PROCEDURE; Preliminary Checks; Leak Test & Evacuation; Crankcase Heater Operation

Table 3 — Electrical Data (60 Hz)
OUTDOOR
i imit ooun
V/PH
OPER VOLTS*
COMPR FAN
Cl A
MCA
MAX FUSE
OR HACR TYPE
UNI I oonu
Max
Min
LRA RLA
rLM
CKT BKR AMPS
018
52 0 84 .70
120 15
024
60.0 10.6 70
140 20
030
036
208/230-1 254
187
65 0
82 0
13.5
16 5
70
1 45
180
22 0
30
35
048
127 0 25 0
1 45
33 0
50
060
135 0 30.7 1.45
40 0
60
036
67 5 10.0
1 45
140
20
048
208/230-3
254
187
98 5
15 4 1.45 21 0 35
060
105.0 19.6 1.45 26 0 45
036
33 8 50 80 70 15
048
460-3
506 414
49 3 77
80
11 0
15
060
55 0
104 .80 14.0 20
FLA — Full Load Amps
HACR — Heating, Air Conditioning, Refrigeration
LRA — Locked Rotor Amps
MCA — Minimum Circuit Amps per NEC Section 430-24
RLA — Rated Load Amps (compressor)
*Permissible limits of the voltage range at which unit will operate
satisfactorily
NOTE: Control circuit is 24v on all units and requires external
power source
Example: Supply voltage is 460-3-60.
START-UP
AB = 452 volts
BC = 464 volts
AC - 455 volts
Average Voltage =
452 + 464 + 455
3
1371
3
= 457
Determine maximum deviation from average voltage
(AB) 457 - 452 = 5 volts
(BC) 464 - 457 = 7 volts
(AC) 457 - 455 = 2 volts
Maximum deviation is 7 volts.
Determine % voltage imbalance:
% Voltage Imbalance = 100 x —= 1.53%
This amount of phase imbalance is satisfactory as it is
below the maximum allowable 2%.
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
nameplate rating
3 All service valves must be open.
4. Crankcase heater must be tight on compressor
crankcase.
Leak Test field piping and fan coil by pressure method
described in Carrier Standard Service Techniques
Manual, Chapter 1, Section 1-6. Use R-22 at approxi¬
mately 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
24 hours to be sure all refrigerant is out of the oil . To
energize crankcase heater, proceed as follows: set space
thermostat above ambient so there will be no demand for
cooling. Close field disconnect. The crankcase heater
is now energized.
IMPORTANT: If the supply voltage phase im¬
balance is more than 2% contact your local electric
utility company immediately.
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.
Evacuate and Dehydrate field piping and fan coil
by either of the methods described in Carrier Standard
Service Techniques Manual, Chapter 1, Section 1-7.
A CAUTION
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 system charge or personal injury.
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