MAXA BDS28A, Technical Manual

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15
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Faults of temperature sensors
Designation of sensors Faults
Indoor ambient temperature The sensor is detected to be open-circuited or short-circuited for successive 30 seconds.
Indoor tube temperature The sensor is detected to be open-circuited or short-circuited for successive 30 seconds.
Outdoor ambient temperature The sensor is detected to be open-circuited or short-circuited for successive 30 seconds.
Outdoor tube temperature
The sensor is detected to be open-circuited or short-circuited for successive 30 seconds, and no
detection is performed within 10 minutes after defrost begins.
Exhaust
After the compressor has operated for 3 minutes, the sensor is detected to be open-circuited or
short-circuited for successive 30 seconds.
Overload
After the compressor has operated for 3 minutes, the sensor is detected to be open-circuited or
short-circuited for successive 30 seconds.
8
Power-failure memory protection
Memory content: mode, up-down purging, lighting, set temperature, and set fan speed. After having power failure, it can
automatically start operating according to the memory content after being powered on again. If no timing function is set in the
final remote control order, the system will memorize the latest remote control order and then operate based on the manner
set during the latest time. There is common timing function included in the latest remote control order. If the system has
power failure when the timed time is still not reached, the system will memorize the timing function in the latest remote
control order after being powered on again, and the timing time will be calculated from the power-on time again. If there is
timing function in the latest remote control order, when the timed time is reached and there is power-failure after the system
conduct the action of the set timed start or timed stop, then after powered on again, the system will memorize the operating
condition before power failure and will not implement the timing action, and also the moment timing will not be memorized.
8. TROUBLESHOOTING
8.1 Malfunction diagnosis should be performed as below procedure
Step Malfunction diagnosis procedure
1 Conform malfunction
2 Read out the error code for indoor/outdoor unit and then find out the corresponding malfunction name
3 Troubleshooting and maintenance (refer to the content as below for details)
Note : There’s high capacity electrolytic capacitor on outdoor unit’s main board. Therefore, there’s still high voltage (DC
280V-380V, which is depending on the input voltage) in the capacitor even if the power is disconnected.
That voltage can only be decreased to the safety valve after more than 20mins. There will be electric shock if you touch the
electrolytic capacitor within 20mins. Therefore, if it needs to maintain it after disconnecting the power, you must discharge
the electrolytic capacitor according to below method.
8.2 Confirmation
(1) Confirmation of Power Supply
Confirm that the power breaker operates (ON) normally;
(2) Confirmation of Power Voltage
Confirm that power voltage is AC 220–230–240 ±10%. If power voltage is not in this range, the unit may not operate
normally.