Starting A System With Liquid Refrigerant In The Compressor - Tecumseh AH5540E Service Handbook

94
SERVICE HANDBOOK

Starting a System with Liquid Refrigerant in the Compressor

When most air conditioning and commercial systems are started up for the first time each season,
a large part of the system refrigerant charge is in the compressor. If there is no crankcase heater
or the heat is not operating properly and the unit must be started at the time of the service, then
follow these guidelines:
• DO NOT attempt to heat the crankcase by applying a flame to the compressor. Not
only is this process slow and likely to be ineffective, it may damage electrical wires,
paint, and the oil.
• If there is no evidence of a compressor electrical problem (for example, tripped breaker
or blown fuse or reports of such), then "jog" the compressor. To "jog" the compressor,
apply power for one to two seconds, then wait 1 to 2 minutes. After 3 or 4 jogs, apply
power continuously.
WARNING! Jogging a compressor that has an electrical problem can increase the
likelihood of terminal venting. To reduce the risk of serious burns or death from terminal
venting with ignition, you must FIRST check for a ground fault whenever you suspect an
electrical problem. See "Identifying Compressor Electrical Problems" on pages 40-41 for
additional information.
Line 1
L
1
Line 2
Hi
Ground
Side
Fan
Compressor -
Unit
Ground
Bleeder
Resistor
L T
2
FIGURE 6-8: Wiring diagram for PSC compressor with run capacitance off-cycle heat.
Rela y - Potential
5
2
Bleeder
Resistor
1 C
A B
Start
Capacitor
2
Temperature Control
Single Pole Contactor
(Room Air Conditioner)
or On - O Switch
External
Thermal Protector
C
S
Run Capacitor
Single Can
(Split Capacitor Optional)
R
Single Phase - PSC Type
Single Phase - CSR Type
Internal
Thermal Protector
(optional)
Motor
Potential Rela y