Intermittent Operation Control For Indoor Fans Of The Indoor Unit At Thermo-Off Side In Heating Operation - Toshiba RAS-5M51U2ACVG-SG Service Manual

9-4. Intermittent Operation Control for Indoor Fans of the Indoor Unit at Thermo-off
Side in Heating Operation
While heating operation is executed in two rooms, if room temperature reached the setup temperature in one
room and thermo-off occurred, the following operations start. (Refer to the figure below.)
1. The indoor unit of the room (A room) in which thermo-off did not occur starts a continuous operation with
the setup number of revolution.
2. The indoor unit of the room (B room) in which thermo-off occurred starts intermittent operation of the indoor fan.
The indoor fan operates with number of revolution of UL or SUL. Fan-ON time is 2 minutes and Fan-OFF
time is 2 to 4 minutes.
However if temperature of the indoor heat exchanger becomes over 55°C or more in B room, the indoor fan
stops the intermittent operation and starts continuous operation.
While heating operation is executed in 2 rooms, if room temperature reached the setup temperature in both
rooms and thermo-off occurred, both indoor units start intermittent operation of the indoor fan.
A room
Thermo-ON continues
0 rpm
B room thermo-ON
↓
Thermo-OFF
↓
Thermo-ON
0 rpm
Indoor fan: Operates with setup number of revolution
B room thermo-OFF
UL
(∗1)
Fan stop
T on
T off
∗ In case which Tc sensor temperature exceeds 55°C
in B room, the fan stops intermittent operation and
starts continuous operation with UL or SUL (∗1).
UL UL
(∗1) (∗1)
Fan stop Fan stop
T on T on
T off T off
- 46 -
B room thermo-ON
Operated with setup number
of revolution
∗1 Operated with UL or SUL
T on=2 min.
T off time
To < 5°C 2 min.
5 < To < 10
3 min.
10 < To
4 min.