Toshiba Carrier MMU-AP0182H2UL Service Manual page 31

No. Item
7 Freeze prevention
control
(Low temp. release)
8 Recovery control
for cooling oil
(Refrigerant)
Outline of specifications
1. In all cooling operation, the air conditioner
operates as de-scribed below based upon temp.
detected by TC1, TC2 and TCJ sensors.
• When "J" zone is detected for 5 minutes, the
thermostat is forcedly off.
• In "K" zone, the timer count is interrupted, and held.
• When " I " zone is detected, the timer is cleared
and the operation returns to the normal operation.
• If "J" zone continues, operation of the indoor fan in
LOW mode continues until it reaches the "
It is reset when the following conditions are
satisfied.
Reset conditions
1) TC1 > 54°F [12°C] and TC2 > 54°F [12°C] and
TCJ > 54°F [12°C].
2) 20 minutes passed after stop.
˚F
(˚C)
I
P1
a
K
Q1
J
2. In all cooling operation, the air conditioner oper-
ates as described below based upon temp.
detected by TC2 and TCJ sensors.
• When "M" zone is detected for 30 minutes, the
thermostat is forcedly off.
• In "N" zone, the timer count is interrupted and held.
• When shifting to "M" zone again, the timer count
restarts and continues.
• If "L" zone is detected, the timer is cleared and
the operation returns to normal operation.
Reset conditions
1) TC1 > 54°F [12°C] and TC2 > 54°F [12°C] and
TCJ > 54°F [12°C].
2) 20 minutes passed after stop.
˚F
L
(˚C)
P2
N
Q2
M
The indoor unit which is under STOP/Thermo-OFF
status or which operates in [FAN] mode performs the
following controls when it received the cooling oil
(Refrigerant) recovery signal from the outdoor unit.
1) Opens PMV of the indoor unit with a constant
opening degree.
2) Operates the drain pump for approx. 1 minute
during recovery control and after finish of control.
I " zone.
TC1 TC2, TCJ
50°F [41°F] 14°F
P1
10°C [5°C] [–10°C]
Q1 32°F [0°C] 7°F [–14°C]
TC2, TCJ
41°F [5°C]
P2
Q2 28°F [–2.0°C]
31
Remarks
TC1: Temperature of indoor
heat exchanger sensor
( ) value:
When the power supply is
turned on, the Forced
thermo becomes OFF if the
temperature is less than this
indicated temperature.
∗ In a Model without TC2,
TC2 is not judged.
• Recovery operation is
usually performed every
2 hours 5 minuts.