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7.2 PROTECTION FUNCTION INTRODUCTION
Sensor T3 (condenser pipe temperature) and T4 (outdoor ambient temperature
)
When open-circuit, compressor, outdoor fan motor and reverse valve will be OFF.
Discharge temperature protection (Heat pump only)
When discharge temp. > 275 °
F
,
compressor will stop.
When discharge temp. < 194 °
F
,
compressor will restart.
High perssure protection (Heat pump only)
When high pressure > 638 PSIG, compressor and outdoor fan motor will stop.
When high pressure < 464 PSIG, compressor and outdoor fan motor will restart
(3 minutes delay necessary).
Low pressure protection (Heat pump only)
Low pressure < 21 PSIG, compressor and outdoor fan motor will stop.
Low pressure > 44 PSIG, compressor and outdoor fan motor will restart
(3 minutes delay necessary).
In stand-by status, the compressor will not start in low pressure protection.
Within 30 mins, if 4 protection cycles occurs, system will restore after power cut-down.
Charge for all systems should be checked against the Charging Chart inside the
access panel cover.
IMPORTANT:Do not operate the compressor without charge in system. Additio n of
R - 410A will raise pressures (vapor, liquid and discharge).
If adding R - 410A raises both vapor pressure and temperature, the unit is over -
c harged.
IMPORTANT: Use industry - approved charging methods to ensure proper system
charge.
When T4 < 5 °
F
,
compressor will stop.
When T4 > 10.4 °
F
,
compressor will restart.
9.CHECKING REFRIGERANT CHARGE
Three phase scrolls are power phase dependent and can compress in more than
one direction.
Verify proper rotation for three phase compressors by ensuring the suction pressure
drops and discharge pressure rises when the compressor is energized.
NOTE: When operated in reverse, a three phase scroll compressors is noisier and
its current draw is substantially reduced compared to marked rated values, please
check the compressor wiring; when connected to the power but the compressor does
not work, the LED indicator on the PCB board of the condensing unit will flash rapidly.
To correct, exchange any two of the power input terminals among the L1, L2 or L3
and this should correct problem.
When the power code connection is error, the LED indicator flashes rapidly.
When the system is in stand -by mode, the LED indicator flashes slowly.
When the system is working in normal mode, the LED indicator will stay lite.
8.0 THREE PHASE COMPRESSOR ROTATION
CAUTION
Use care when handling scroll compressors. Dome temperatures can be hot.
