Toshiba A90-0132, Service Manual

Page: 65 / 176

65
Outline of control
Indoor units
Item Operation explanation and applied data, etc. Remarks
6. Air volume (1) By the command from the remote controller or the central controller, “HIGH”, “MED.”, • During stop
control “LOW”, or “AUTO” operation is permissible. operation, control to
(2) While air volume is in AUTO mode, the air volume is changed according to the prevent cold draft is
difference between Ta and Ts. determined by TC2.
LOW
MED
HIGH
COOL HEAT
Ultra low
compressor
off
HIGH
MED
LOW
+2
+1
Ts
+1
Ts
-1
-2
7. Freeze (1) In cooling operation, the air conditioner operates as described below based upon
prevention temp. detected by TC1 and TC2 sensors.
control (Low • When “J” zone is detected for 5 minutes, the command frequency becomes
temp. release) “S0” to the outdoor unit.
• In “K” zone, the timer count is interrupted, and held.
• When “I” zone is detected, the timer is cleared and the operation returns to
normal operation.
• When the command frequency becomes S0 with continuation of “J” zone,
operation of the indoor fan in LOW mode occurs until it reaches the “I” zone.
It is reset when the following conditions are satisfied.
1) TC1
≥
12 °C and TC2
≥
12 °C
2) 30 minutes after the air conditioner has stopped.
(°C)
Q
P
a
K
I
J
TCI TC2
P 10 -12
Q 0 -15
8. Cooling When the indoor units stand by, thermostat is OFF, or unit operates with “FAN” mode, • Only for 4-way/2-
refrigerant/ PMV of the indoor unit is opened by a certain degree when the cooling oil/heating way ceiling cassette
Heating oil refrigerant recovery signal is received from the outdoor unit. type, operate the
recovery indoor fan inter-
control mittently during the
recovery operation.
9. Short (1) For 5 minutes after the operation has started, the operation is continued even if
intermittent entering thermostat-OFF condition.
operation (2) However, if the thermostat has been turned off by changing the set-up temp., the
compensation thermostat is OFF with even the above condition. The protective control has priority.
control
10. Drain pump (1) During “COOL” operation, the drain pump operates. • When CHECK code
control (2) When the float SW operates, the compressor stops and the drain pump operates. “0b” occurs, the
(3) When the operation of the float SW continues for 2 minutes, a check code is outdoor units stop
generated. and “STANDBY” is
displayed on the
remote controllers
of all the indoor
units.
11