48
Technical Information
Service Manual
(6)Voltage sag protection
After start the compressor, if the time of DC link Voltage sag [U
Sagging protection voltage
] is measured to be less than t Voltage sag protection time , 
the machine should be stop at once, hand on the voltage sag trouble, reboot automatically after 30 minutes.
(7)Communication fault
When you have not received any correct signal from the inner machine in three minutes, the machine will stop for communication fault. When 
you have not received any correct signal from driver IC (aim to the controller for the separating of main control IC and driver IC), and the 
machine will stop for communication fault. If the communication is resumed, the machine will be allowed to operate.
(8)Module protection
Testing the module protective signal immediately after started, once the module protective signal is measured, stop the machine with module 
protection immediately. If the  module protection is  resumed,  the machine will  be allowed to operate.  If the module  protection continuously 
occurs for three times, it should not be resumed automatically, and you should press the ON/OFF button to resume. If the running time of 
compressor exceeds the [t 
Protection times clearing of module
] , the module protection is cleared to recount.
(9)Module overheating protection
1. Starting estimation:
After the compressor stopped working for 180s, if T
Module
<[T
Module frequency limited temperature
](the temperature of hysteresis is 2 ), the machine is allowed 
to  start,  otherwise  it  should  not  be  started,  and  should  be  stopped  to  treat  according  to  the  module  overheating  protection:  The  machine 
should be stopped or transferred to supply air, the trouble should be cleared immediately, and the protection times are not counted.
2. Frequency limited
If [T
Limited frequency temperature of module
] ≤T
Module
 <[T
frequency reducing temperature at normal speed of module
] , you should limit the frequency raising of compressor.
3. Reducing frequency at normal speed and power turn-off:
If  [T
frequency  reducing  temperature  at  normal  speed  of  module
]  ≤T
Module
<[T
frequency  reducing  temperature  at  high  speed  of  module
],  you  should  adjust  the  compressor  frequency  by 
reducing 8Hz/90s till the lower limit; After it was running 90s at the lower limit, if [T
 frequency reducing temperature at normal speed of module
] ≤T
Module
, you should 
stop the machine for module overheating protection;
4. Reducing frequency at high speed and power turn-off:
If [T
frequency reducing temperature at high speed of module
]≤T
Module
 <[T
Power turn-off temperature of module
] you should adjust the compressor frequency by reducing 30Hz/90s 
till the lower limit; After it was running 90s at the lower limit, if [T
 frequency reducing temperature at normal speed of module
] ≤T
Module
, you should stop the machine for 
module overheating protection;
5. Power turn-off:
If the [T
Power turn-off temperature of module
] ≤T
Module
, you should stop the machine for module overheating protection; If T
Module
 <[T
Limited frequency temperature of module
] 
and the compressor has been stopped for 3 minutes, the machine should be allowed to operate.
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 
Protection times clearing of module
] , the discharge protection is 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 
Protection times clearing of compressor overloading
] 30 minutes.
(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 
Limited frequency phase current
] ≤[I
 Phase current T frequency reducing phase current
] , you should limit the frequency raising of compressor.
2. Reducing Frequency
If [I 
Frequency Reducing Phase Current
]≤I Phase Current<[I
 Power Turn-Off Phase Current
], the compressor shall continue to reduce frequency till the lowest frequency 
limit or out of the condition of reducing frequency;
3. Power turn-off
If [I 
Phase Current
]≥[I 
Power Turn-Off Phase Current
], the compressor phase current shall stop working for overcurrent protection; if [I 
Phase Current
]≤[I 
Frequency Reducing 
Phase Current
], and the compressor have stopped working for 3 min, the machine shall be allowed to operate;
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 
Clearing Time of 
Compressor Phase Current Times
] , the overcurrent protection is cleared to recount.