Voltage Abnormity Protection For Dc Bus; Abnormity Protection For Four-Way Valve; Pfc Protection; Failure Detection For Sensor - ComfortStar CARAT18-CD Service Manual

If it still can't run automatically when the out-of-step protection for compressor happens to stop working for 6
times in succession, it needs to press ON/OFF to operate. And if the running time is more than 10 min, the power
turn-off times for out-of-step protection shall be cleared and recounted.

(13) Voltage Abnormity Protection for DC Bus

1. To detect voltage abnormity protection for dc bus after completing the pre-charge:
(1) Over-High Voltage Protection for DC Bus:
If it found the DC bus voltage U
shall show the DC over-high voltage failure; it should clear out the failure when the voltage dropped to U
and the compressor stopped for 3 min.
Jiekuangchun Recovery]
(2) Over-Low Voltage Protection for DC Bus:
If it found the DC bus voltage U
shall show the DC over-low voltage; and it should clear out the failure when the voltage raised to U
and the compressor stopped for 3 min.
Wantuochun Recovery]
2. To detect voltage abnormity protect for DC bus when getting electricity:
If it found the DC bus voltage U
failure for DC Bus. And the failure can't recover except to break off and get the electricity.

(14) Abnormity Protection for Four-way Valve

Under the model of heating operation in good condition: the compressor is detected T
Abnormity Temperature Difference For Four-Way Valve Reversion
reversion abnormity. And then it can run if stop the reversion abnormity 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).

(15) 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.

(16) 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.
[U
DC DC Jiekuangchun Protection]
[U
DC DC Wantuochun Protection]
[U
DC DC——Over-High Voltage]
]), during the running, it should be regarded as four-way valve
, turn off PFC and stop the compressor at once, and it
, turn off PFC and stop the compressor at once, and it
, turn off the relay at once, and shows voltage abnormity
[U
DC DC
[U
DC DC
(T —[T
Inner Tube Inner Ring