Sharp AE-X3M18JR Service Manual page 11

9. PUMP DOWN SWITCH
When the PUMP DOWN SWITCH (SW1) is pressed for 5 seconds or
more, the total A/C system will start its TEST RUN automatically and
the compressor frequency will be 48.3 Hz. When operating only the
outdoor unit (cooling 48.3 Hz fixed mode) To make only the outdoor
unit run in cooling mode, and apply a voltage of 230 V AC to N and L
on the terminal board and push the pump down switch. (SW1) (Avoid
operating the outdoor unit alone for long periods of time.)
10. CONTROL OF COMPRESSOR OR AND EXPAN-
SION 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, the 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.
11. DEFROST OPERATION
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. Defrost-
ing stops when the temperature of the outdoor heat exchanger
goes above approximately 15°C or defrosting time exceeds 10 min-
utes.
Defrost
mask time
Heating
begins
Defrosting
Max. 10 min.
2) Defrosting
If the compressor operation time is more than 20 minutes in the
heating mode and the outdoor air temperature and outdoor heat
exchange temperature satisfy the defrosting conditions, the
defrosting operation is started. When the defrosting operation is
started, the indoor fan starts to run intermittently. When the outdoor
heat exchanger temperature reaches approx. 15°C or above or
when the defrosting time exceeds 10minutes, the defrosting opera-
tion is quit.
Defrost Defrost
mask time mask time
Defrosting
Max. 10 min.
More than
20 min.
Heating
operation
start
3) During defrosting
When defrosting begins, the compressor stops. Approximately 1
minutes later, the compressor reactivates in the refrigeration cycle,
and the outdoor heat exchanger is defrosted. Each mode is as fol-
lows:
The outdoor fan is s topped
The operating frequency is as shown in the table below.
The indoor fan is s topped.
All expansion valve are open.
for 5 minutes 3900 rpm
after that 3700 rpm
4) Defrost stop
When defrosting time exceeds 10 minutes When the temperature
of the outdoor heat exchanger rises above approximately 15°C
Defrost stop is determined by either of the above conditions, and
the compressor is stopped. At the same time, the outdoor fan go
ON. The compressor is reactivated in the heating cycle 1 minutes
after it was stopped, and normal control resumes.
12. Power factor module Output voltage
If a voltage error over 450V is detected at power factor module output
voltage, the compressor is stopped for 3 minutes. In this case, the out-
door fan does not stop for 3 minutes, and another 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 reset is performed. At this time, the 3 minutes delay for
control of the outdoor unit will not function; therefore, do not cancel by
removing the plug and cutting the power.
.
2 – 3
AEX3M18JR
More than More than
20 min. 20 min.
Defrosting Defrosting
Max. 10 min. Max. 10 min.