Gree GWH18MC-K3DNA2G Service Manual page 36

Service Manual
4. Reducing frequency at high speed and power turn-off:
If [T
frequency reducing temperature at high speed of module
till the lower limit; After it was running 90s at the lower limit, if [T
for module overheating protection;
5. Power turn-off:
If the [T
Power turn-off temperature of module
] and the compressor has been stopped for 3 minutes, the machine should be allowed to operate.
module
6. If protection continuously occurs for six times, it should not be resumed automatically, and you should press the ON/OFF button to
resume. During the process of running, if the running time of compressor exceeds the [t
cleared to recount. Stopped or transferred to supply air mode will clear the trouble times immediately (if the trouble can not be resumed,
mode transferring also will not clear it).
(10)Compressor overloads protection
If you measure the compressor overload switch action in 3s, the compressor should be stopped for overloading. The machine should be
allowed to operate after overload protection was measured to resume. If the overloading protection continuously occurs for three times, it
should not be resumed automatically, and you should press the ON/OFF button to resume. The protection times of compressor is allowed
to clear after the compressor run [t
(11)Phase current overcurrent protection of compressor
During the running process of compressor, you could measure the phase current of the compressor, and control it according to the following
steps:
1. Frequency limited
If [I ] ≤[I
Limited frequency phase current
2. Reducing Frequency
If [I ]≤I
Frequency Reducing Phase Current
or out of the condition of reducing frequency;
3. Power turn-off
If [I ]≥[I
Phase Current Power Turn-Off Phase Current
], and the compressor have stopped working for 3 min, the machine shall be allowed to operate;
Reducing Phase Current
4. If the overcurrent protection of compressor phase current continuously occurs for six times, it should not be resumed automatically, and
you should press the ON/OFF button to resume. During the process of running, if the running time of compressor exceeds the [t
] , the overcurrent protection is cleared to recount.
Compressor Phase Current Times
(12) Starting-up Failure Protection for Compressor
Stop the compressor after its starting-up fails, restart it after 20s if the fault doesn't shows, and if they are all failing for the successive start
3 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 press ON/OFF. And the compressor should be cleared the times after it run 2 min.
(13) Out-of-Step Protection for Compressor
The out-of-step protection signal should be detected immediately after starting-up compressor, and once find the out-of-step protection
signal, 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
voltage failure; it should clear out the failure when the voltage dropped to U
2.Over-Low Voltage Protection for DC Bus:
If it found the DC bus voltage U
voltage; and it should clear out the failure when the voltage raised to U
Technical Information
]≤T <[T
Module Power turn-off temperature of module
] ≤T , you should stop the machine for module overheating protection; If T
Module
Protection times clearing of compressor overloading
Phase current T frequency reducing phase current
<[I
Phase Current Power Turn-Off Phase Current
], the compressor phase current shall stop working for overcurrent protection; if [I
>[U
DC DC Jiekuangchun Protection
<[U
DC DC Wantuochun Protection
] you should adjust the compressor frequency by reducing 30Hz/90s
frequency reducing temperature at normal speed of module
] 30 minutes.
] , you should limit the frequency raising of compressor.
], the compressor shall continue to reduce frequency till the lowest frequency limit
], turn off PFC and stop the compressor at once, and it shall show the DC over-high
<[U
DC DC Jiekuangchun Recovery
], turn off PFC and stop the compressor at once, and it shall show the DC over-low
>[U
DC DC Wantuochun Recovery
] ≤T , you should stop the machine
Module
<[T
Module
] , the discharge protection is
Protection times clearing of module
] and the compressor stopped for 3 min.
] and the compressor stopped for 3 min.
Limited frequency temperature of
]≤[I
Phase Current Frequency
Clearing Time of
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