Westinghouse WHZ09WMA21S Service Manual page 29

Test the jumper terminals
Note:
When the whole machine is powered up, if the external unit does not work, to rule out the
communications failures, adopt screening method such as short circuit on the jumper terminals to see
if the external unit can be started normally or similar method.
There are two blue terminals on the outdoor control panel, as shown above.
Application: Short out the terminals, and power up the outdoor unit, then the outdoor unit may run
independently. It can be determined that there is no internal and external communication faults.
Trouble Diagnosis of Protection
Protection diagnosis of the complete machine (all types of protection during operation, i.e.
under-voltage, over-voltage and overcurrent protection)
Note:
List all types of protection that may occur to the complete machine and describe the conditions
and signs of the start, course and end of such protection.
Voltage protection
Protection against AC input over-voltage/under-voltage
1.Conditions for protection against AC input over-voltage/under-voltage:
If the input AC voltage is greater than "protective over-voltage value" or less than "protective
under-voltage value" for five seconds, over-voltage/under-voltage protection tarts.
2.Protection actions against AC input over-voltage/under-voltage
The system stops operation.
3. Conditions for ending AC input over-voltage/under-voltage:
If the input AC voltage is lower than "the protective over-voltage value" -10V, or higher than "the
protective under-voltage value" +10V, the over-voltage/under-voltage protection will be released.
Current protection:
1.Protection against over-current
Conditions for over-current protection: if the current is equal to or greater than "current value for starting
the refrigeration current protection (E2 value)" for six seconds, over-current protection starts.
Protection actions against over-current: indoor display screen and outdoor indicator give indications, the
compressor and outdoor fan stop, but indoor fan runs normally.
Condition for ending over-current protection: when the current drops below "current value for releasing
the refrigeration current protection (E2 value)", over-current protection will be released.
2.Frequency decreasing for over-current
Conditions for over-current frequency decreasing: if the current is equal to or greater than "current value
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