Service and Parts Manual
40 PB
OPERATION
9-24k Sequence of Operation
(12) Starting-up Failure Protection for Compressor
Stop the compressor after staring fails, then restart it after 20s if the fault doesn't show.If starting fails 3 consecutive 
times, it shall be reported as Starting-up Failure, and then restart up it after 3 min. When it still not be able to operate through carry out the
above process for 5 times, it is available if you press ON/OFF.  The compressor should be cleared after it runs 2 min.
(13) Out-of-Step Protection for Compressor
the out-of-step protection shall be stopped; if it can run for lasting power turn-off 3 min, the machine shall be allowed to operate. 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.
(14) Voltage Abnormity Protection for DC Bus
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  DCbus voltage U
DC
 >[U
DC Jiekuangchun  Protection
], turn  off PFC and stop  the compressor  at once, and  it shall  show the  DC over-high
voltage failure; it should clear out the failure when the voltage dropped to U
DC
 <[U
DC Jiekuangchun Recovery
] and the compressor stopped for 3 min.
2.Over-Low Voltage Protection for DC Bus:
If it found the  DC  bus  voltage  U
DC
 <[U
DC Wantuochun Protection
], turn off PFC  and  stop the compressor at  once,  and  it  shall  show  the DC over-low
voltage; and it should clear out the failure when the voltage raised to U
DC
 >[U
DC Wantuochun Recovery
] and the compressor stopped for 3 min.
3.To detect voltage abnormity protect for DC bus when getting electricity:
If it found the DC bus voltage U
DC
 >[U
DC-Over-High Voltage
], turn off the relay at once, and shows voltage abnormity failure for DC Bus. And the failure
can't recover except to break off and get the electricity.
(17) Failure Detection for 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.
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 the same time;
2. It shows the failure is cleared out if PFC Protection stopped working 3 min and recovers to run automatically;
3. If the PFC protection failure occurs 3 times consecutively, it will be available if you 
press ON/OFF; and clear the PFC Protection
times when start up PFC for 10min.
4. Module Temperature Sensor:
(15)Abnormity Protection for Four-way Valve
Under  the  model  of  heating operation  in good  condition: the compressor  is  detected  [T
Inner Tube
  <(T
Inner  Ring
-T
 Abnormity  Temperature  Difference  For  Four-Way Valve 
Reversion
)], during the running, it should be regarded as four-way valve 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).
(16) PFC Protection
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:
5. Disposal for Sensor Protection
(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  neednt 30s avoiding  the  module over-
heated).
(c) Detect the sensor failure at all times in the testing mode.
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.










