Read Sharp AE-XM24CR (serv.man8) Service Manual online
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AY-XM7/9/12CR
AY-XPM7/9/12CR
AE-XM18/24CR
AY-XPM7/9/12CR
AE-XM18/24CR
2-4 POWER TRANSISTOR MODULE PROTECTION
If the temperature of the chips in the power
transistor module exceeds 100ÅãC, the compressor
is stopped.
In this case, the outdoor fan is not stopped until the
temperature of power module drops below 85ÅãC.
In 90 seconds after the compressor is stopped, if the
temperature is below 85ÅãC, another starting try will
be made. Three retries are allowed. On the fourth
retry, a complete stop request signal is sent to the
indoor unit, and the outdoor unit will remain stopped
until the indoor operation is stopped.
transistor module exceeds 100ÅãC, the compressor
is stopped.
In this case, the outdoor fan is not stopped until the
temperature of power module drops below 85ÅãC.
In 90 seconds after the compressor is stopped, if the
temperature is below 85ÅãC, another starting try will
be made. Three retries are allowed. On the fourth
retry, a complete stop request signal is sent to the
indoor unit, and the outdoor unit will remain stopped
until the indoor operation is stopped.
2-5 SERIAL SIGNALS
Serial signals consist of all 96-bit signals.
If the condition as outdoor unit unable to receive a
serial signal from the indoor unit continues for 30
seconds, it closes the expansion valve which
corresponds to the room which can not be
communicated.
If all indoor units can not communicate with the
outdoor unit, the compressor is stopped.
If the condition as outdoor unit unable to receive a
serial signal from the indoor unit continues for 30
seconds, it closes the expansion valve which
corresponds to the room which can not be
communicated.
If all indoor units can not communicate with the
outdoor unit, the compressor is stopped.
2-6 THERMISTOR OPEN OR SHORT
When compressor, heat exchanger, outdoor
thermistor, suction thermistor (CN8A) are in OPEN
or SHORT condition, even if they are in the condition
which an operation signal is transmitted from
indoors, the compressor will not start.
If any of the 2 suction thermistors (CN8B) become
OPEN or SHORT resistance, the protective
procedure will work only for the cycle corresponding
to the malfunctioning suction thermistor.
thermistor, suction thermistor (CN8A) are in OPEN
or SHORT condition, even if they are in the condition
which an operation signal is transmitted from
indoors, the compressor will not start.
If any of the 2 suction thermistors (CN8B) become
OPEN or SHORT resistance, the protective
procedure will work only for the cycle corresponding
to the malfunctioning suction thermistor.
2-7 MAIN RELAY
When the air-conditioners in all rooms stop, two
main relays of the outdoor unit will turn off.
main relays of the outdoor unit will turn off.
2-8 MISWIRING CHECK
"Miswiring check" is conducted by detecting the
indoor heat exchanger temp.
For example, when the expansion valve for only
room A is open, and the wiring is correct, the indoor
heat exchanger temp for room A will reduce.
If the wiring is incorrect, the indoor heat exchanger
temp for a different room will reduce.
indoor heat exchanger temp.
For example, when the expansion valve for only
room A is open, and the wiring is correct, the indoor
heat exchanger temp for room A will reduce.
If the wiring is incorrect, the indoor heat exchanger
temp for a different room will reduce.
2-9 SAFETY TIME
When the unit is operated by the remote control after
the breaker is turned on, the safety device of the
compressor will work and the compressor will not
operate for 90 seconds.
the breaker is turned on, the safety device of the
compressor will work and the compressor will not
operate for 90 seconds.
2-10 PUMP DOWN SWITCH
When the PUMP DOWN SWITCH (SW51) is
pressed for 5 seconds or more, the total A/C
system will start its TEST RUN automatically and
the compressor frequency will be 55 Hz.
When operating only the outdoor unit (cooling 55
Hz fixed mode) To make only the outdoor unit run
incooling mode, and apply a voltage of 230 V AC
to L and N on the terminal board and push the
pump down switch. (SW51) (Avoid operating the
outdoor unit alone for long periods of time.)
pressed for 5 seconds or more, the total A/C
system will start its TEST RUN automatically and
the compressor frequency will be 55 Hz.
When operating only the outdoor unit (cooling 55
Hz fixed mode) To make only the outdoor unit run
incooling mode, and apply a voltage of 230 V AC
to L and N on the terminal board and push the
pump down switch. (SW51) (Avoid operating the
outdoor unit alone for long periods of time.)
2-11CONTROL OF COMPRESSOR OR AND
EXPANSION VALVE
For 90 seconds after turning on the AC power, the
compressor will not be activated even if indoor units
request the compressor to do so. If the compressor
receives a request from one or more indoor units
after 90 seconds have passed, it will be turned on
and the expansion valve corresponding to the
requesting indoor unit will be opened.
When the indoor unit of a room requests for the
cooling operation to the outdoor unit and it runs
responding to the request, requests for the heating
can't be accepted if the indoor units in other rooms
send individual requests.
If the indoor unit in another room sends a request for
the heating operation, the operation lamp and timer
lamp of the indoor unit in that room start flashing in
turn to inform that the unit is in the standby mode.
If the operation in one room is stopped while the
indoor unit in another room is in the stand-by mode,
the operation mode requested by the indoor unit
which is now in the stand-by mode will be accepted.
At this time, the compressor will be temporarily
stopped to switch the four- way valve and restart
after 90 seconds.
During the cooling or dry operation, the
expansion valve corresponding to the indoor unit
that is not running is closed. Therefore, th refrigerant
will not flow into those units.However,if the heating
operation is in progress, it is possible that it flows
into indoor units which are out of operation
depending on the cycle conditions. As a result, the
indoor exchanger may be heated up even if it
For 90 seconds after turning on the AC power, the
compressor will not be activated even if indoor units
request the compressor to do so. If the compressor
receives a request from one or more indoor units
after 90 seconds have passed, it will be turned on
and the expansion valve corresponding to the
requesting indoor unit will be opened.
When the indoor unit of a room requests for the
cooling operation to the outdoor unit and it runs
responding to the request, requests for the heating
can't be accepted if the indoor units in other rooms
send individual requests.
If the indoor unit in another room sends a request for
the heating operation, the operation lamp and timer
lamp of the indoor unit in that room start flashing in
turn to inform that the unit is in the standby mode.
If the operation in one room is stopped while the
indoor unit in another room is in the stand-by mode,
the operation mode requested by the indoor unit
which is now in the stand-by mode will be accepted.
At this time, the compressor will be temporarily
stopped to switch the four- way valve and restart
after 90 seconds.
During the cooling or dry operation, the
expansion valve corresponding to the indoor unit
that is not running is closed. Therefore, th refrigerant
will not flow into those units.However,if the heating
operation is in progress, it is possible that it flows
into indoor units which are out of operation
depending on the cycle conditions. As a result, the
indoor exchanger may be heated up even if it
is not
activated. This is not abnormal.
When the operations in all rooms are stopped, the
compressor is off and the expansion valves in all
rooms are fully opened.
When the operations in all rooms are stopped, the
compressor is off and the expansion valves in all
rooms are fully opened.
2-12 DEFROST OPERATION
(1) Overview
(1) Overview
Defrosting begins during heating if the conditions for
compressor operation time and outdoor heat
exchanger temperature are met. When defrosting
begins, the indoor and outdoor fans stop.
Defrosting stops when the temperature of the
outdoor heat exchanger goes above approximately
15 ˚C or defrosting time exceeds 10 minutes.
compressor operation time and outdoor heat
exchanger temperature are met. When defrosting
begins, the indoor and outdoor fans stop.
Defrosting stops when the temperature of the
outdoor heat exchanger goes above approximately
15 ˚C or defrosting time exceeds 10 minutes.
Defrost
mask time
Defrost
mask time
Defrost
mask time
Heating
begins
Defrosting
Max. 10 min.
Defrosting
Max. 10 min.
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