Midea MRBT-200CWN1-D - Page 74

MCAC-RTSM-2015-01 60Hz R410a ClimaMaster Tropical Rooftop Package Unit
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8). P4：Protection for High/Low Pressure or exhaust temp. (High pressure protection value：4.4MPa,
High pressure protection value：0.14MPa；air discharge temp. protection value: 130℃ above)
9). Indoor fan motor didn’t work.
10). Outdoor fan motor didn’t work.
When P4 display, detect High/Low pressure
testing point by pressure gauge and discharge
point temp. by thermometer. Conform if all testing
values are normal.
The main board display P4 is
normal.
Detect by multi-meter if the high/low pressure
switch two sides and air discharge switch two
sides exist current circuit.
Replace high/low pressure switch
and air discharge temp. switch,
detect them again.
Detect if there exist current from main
board to indoor fan.
Replace the main board.
Detect if there exist power supply from
main board to outdoor fan.
Replace the capacitor of outdoor fan,
detect it again, if the outdoor fan work.
No
Replace the main board.
Yes
No
Replace outdoor fan.
Remove the problem
No
Yes
No
Yes
Yes
Replace the main board.
No
Replace indoor fan capacitor, detect it
again, Conform if the indoor fan works.
No
Replace the indoor fan.
Yes
Remove the problem
Yes