Contactor Compressor; Compressor & Starting Component Check-Out Procedure - Cornelius IAC322 Pocket Manual

maintain a receiver outlet pressure equal to or above the dome pres-
sure setting of the valve the dome pressure will force the valve por-
tage to change closing the condenser port and opening the bypass
port from the compressor discharge line. This allow the high pres-
sure vapor from the discharge port to "buck" the receiver pressure
back up. With the condenser port closed, the refrigerant is backed up
in the condenser, basically reducing the condenser size, assisting in
maintaining the discharge portage flow and increasing the head
pressure.
Remember, sense of touch to the lines of the headmaster will deter-
mine the flow path the headmaster is in, condenser to receive or by-
pass to receiver.
High side gauge installed at the receiver outlet valve will determine
if the headmaster is functioning to maintain the proper operating
pressure.
In the event the control appears to be "stuck in bypass", the pressure
drop across the headmaster must be measured. With a gauge
installed at the receiver outlet valve and the high side service valve,
the pressure difference at these two points must be less the 15 PSI
(1.03 Bars). Three most common causes of an excessive pressure
drop are shortage of refrigerant, kinked remote lines, and excessive
line length.
Eliminate refrigerant shortage first. Add refrigerant in two pound in-
crements (not to exceed six pounds) to determine if it corrects the
pressure drop. If pressure drop is not corrected, inspect line set for
sharp bends or kinks, correct as required. If adding refrigerant does
not correct continued (bypass) condition and line set is not dam-
aged, replace headmaster.

Contactor Compressor

The contactor serves as the voltage supply switch for the compres-
sor circuit. Voltage to the coil of the contactor is supplied by the cir-
cuit board.
Check Out:
The two (2)* line supply screws of the contactor should always have
supply voltage present when voltage is on to the product.
The other two (2)* screws (load) should have line voltage when the
contactor is energized. The contactor coil receives its supply voltage
from the circuit board. Should the contactor fail to energize:
Check for supply voltage from circuit board, lead connections to
contactor coil, and ohms value of coil.
* (3) if the product is 3 phase
Compressor & Starting Component
Check-Out Procedure
When compressors fail to start or run properly, it is normally the ex-
ternal electrical supply or the compressor start components that are
47 TD 204