Gree GWH18RC-K3DNA3G Service Manual page 31

3.To detect voltage abnormity protect for DC bus when getting electricity:
If it found the DC bus voltage U
failure can't recover except to break off and get the electricity.
(15)Abnormity Protection for Four-way Valve
Under the model of heating operation in good condition: the compressor is detected [T
)], during the running, it should be regarded as four-way valve reversion abnormity. And then it can run if stop the reversion abnormity
Reversion
protection for four-way valve 3 min; and if it still can't run when the reversion abnormity protection for four-way valve happens to stop
working for 3 times in succession, it is available if presses ON/OFF.
Attention: the protection shall be shielded during the testing mode and defrosting process, and it shall be cleared out the failure and its
times immediately when turning off or delivering wind / cooling / dehumidifying mode conversed (the inverted mode don't clear out the
failure when it can't recover to operate).
(16) PFC Protection
1. After start up the PFC, it should detect the protection signal of PFC immediately; under the condition of PFC protection, it should turn off
the PFC and compressor at one time;
2. It shows the failure is cleared out if PFC Protection stopped working 3 min and recovers to run automatically;
3. If it still can't run when it occurs PFC protection for 3 times in succession, it is available if presses ON/OFF; and clear the PFC Protection
times when start up PFC for 10min.
(17) Failure Detection for Sensor
1. Outdoor Ambient Sensor: detect the failure of sensor at all times.
2. Outdoor Tube Sensor: You should not detect the failure of outdoor tube sensor within 10 minutes heating operation compressor except
the defrosting, and you could detect it at other time.
3. Outdoor Exhaust Sensor:
(a) The compressor only detect the sensor failure after it start up 3 min in normal mode;
(b) It should detect the exhaust sensor failure immediately in the testing mode.
4. Module Temperature Sensor:
(a) Short-Circuit Detection: the compressor should be detected immediately when the module temperature sensor occurs short-circuits;
(b) Open-Circuit Detection: the compressor should be detected on open-circuit when it runs 3min (it needn't 30s avoiding the module over-
heated).
(c) Detect the sensor failure at all times in the testing mode.
5. Disposal for Sensor Protection
(1) When the short-circuit of sensor is detected within 30s, It is regarded as the temperature of sensor over-high (or infinitely high), and now
according to the over-high sensor, the machine should carry out the corresponding protection to stop working, and show the corresponding
temperature shutdown protection and sensor failure at the same time (for example: the compressor stops immediately when the outdoor
tube sensor short-circuit, and the machine shall show the overload protection and outdoor tube sensor failure).
(2) When the open-circuit of sensor is detected within 30s, The protection shall be stopped and it shall show the corresponding sensor
failure.
6. Electric Heating Function of Chassis
(1) When T ≤0ºC , the electric heating of chassis will operate;
outdoor amb.
(2) When T >2ºC , the electric heating of chassis will stop operation;
outdoor amb.
(3)When 0ºC<T ≤2ºC , the electric heating of chassis will keep original status.
outdoor amb.
7. Electric Heating Function of Compressor
(1) When T ≤-5ºC, compressor stops operation, while the electric heating of compressor starts operation;
outdoor amb.
(2) When T >-2ºC, the electric heating of compressor stops operation;
outdoor amb.
(3) When -5ºC<T
outdoor amb.
28
>[U ], turn off the relay at once, and shows voltage abnormity failure for DC Bus. And the
DC DC-Over-High Voltage
≤-2ºC, the electric heating of compressor will keep original status.
<(T -T
Inner Tube Inner Ring Abnormity Temperature Difference For Four-Way Valve
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Service Manual