Sharp AE-XM30GR, Service Manual, Page: 12 / 42

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CHAPTER 3.
FUNCTION AND OPERATION OF PROTECTIVE PROCEDURES
[1] PROTECTIVE FUNCTIONS AND OPERATIONS
NO. Function
Operation
Description Detection time Restart condition
1 DC over current
Compressor is stopped if a current approxi-
mately 25A or more flows in the power tran-
sistor module.
During compres-
sor operation Automatically restarts after
safety time (180 seconds)
4 times Yes Yes
2 AC over current
Lowers the operating frequency if the com-
pressor AC current exceeds set value(19.3).
Stops the compressor if the current exceeds
at minimum frequency.
During compres-
sor operation Automatically restarts after
safety time (180 seconds)
4 times Yes Yes
3
Compressor over-
heat prevention con-
trol
Lowers the operating frequency if the tem-
perature of the compressor thermistor (TH1)
rises above 108

C. Compressor is stopped if
the thermistor stays above 108

C for 2 min-
utes at minimum frequency.
During compres-
sor operation Automatically restarts after
safety time (180 seconds)
No limit No No
4
Compressor high
temperature error
Compressor is stopped if the compressor
thermistor is above 113

C (Or when TH1
shorts)
During compres-
sor operation
Automatically restarts when
thermistor (TH1) tempera-
ture falls below 99

C
(approximately 30 minutes)
4 times Yes Yes
5
Outdoor heat
exchanger overheat
prevention control
Lowers the operating frequency if the tem-
perature of the outdoor heat exchanger rises
above 57

C during cooling. Stops the com-
pressor if thetemperature stays above 57

C
for 2 minutes at minimum frequency
During compres-
sor operation Automatically restarts after
safety time (180 seconds)
No limit No No
6 Thermistor short
Compressor ia stopped, if heat exchanger or
outdoor thermistor shorts.Close the expan-
sion valve of the corresponding room, if
some suction thermistor shorts.
When the roo-
mis activated-
turns ON andthe
compres-
sorstarts.
Operation OFF 1 time Yes Yes
7 Thermistor open
Compressor is stopped, if compressor or
heat exchanger or outdoor thermistor opens.
Close the expansion valve of the corre-
sponding room, if some suction thermistor
shorts. opens.
When the room
turns ON and the
compressor
starts.
Operation OFF 1 time Yes Yes
8
AC abnormal cur-
rent
Compressor is stopped, if the oper-ating fre-
quency is above 70Hz and the compressor
current is below 0.8A.
During compres-
sor operation Automatically re-starts after
safety time.(180 sec.)
4 times Yes Yes
9 Serial signal error
INDOOR
If open, while timer LED blinks, op-eration is
continued. If short, operation is continued.
OUTDOORC
loses the expansion valve of the corre-
sponding room if the outdoor unit does not
receive a serial signal from one or more
indoor unit for 30 seconds.
Compressor is stopped, if the out-door unit
does not receive a serial signal from all
indoor units.
During operation
Automatically re-starts as
soon as the serial commu-
nication becomes possible.
No limit Yes Yes
10
Miswiring check
error Compressor is stopped, and miswiring check
operation ends. During miswiring
operation
Miswiring check op-eration
will not re-start automati-
cally.
4 times Yes Yes
11
Indoor heat
exchanger overheat
prevention control
Lowers the operating frequency if the tem-
perature of any of indoor heat exchanger
rises high temper-ature during heating.
Stops the compressor if the tem-perature
srays high for 2 minutes at minumum fre-
quency.
During compres-
sor operation Automatically re-starts after
safety time.(180 sec.)
No limit No No
12
Power factor mod-
ule (Active filter)
error
When a power factor module errorinput is
detected. During compres-
sor operation Automatically re-starts after
safety time.(180 sec.)
4 times Yes Yes
13
DC Compressor
rotatione rror In the case that the feed back signal from the
compressor is not input orabnormal.
During com-
presso ropera-
tion
Automatically re-starts after
safety time.(180 sec.)
8 times Yes Yes