Toshiba RAS-M10GDV-E Service Manual page 17

Toshiba ilmalämpöpumput myy, huoltaa ja asentaa: Jäähdytinpalvelu RefGroup Oy.
[Cold draft preventing control]
The upper limit of fan revolution speed is shown
below.
TC
(˚C)
44 33
43 32
31 20
30 19
2
*
A + 4 A
A – 8 A – 8
Starting
FAN
of FAN
AUTO
Manual
NOTES :
1 Stops for 2 minutes after thermostat-OFF.
*
2 24°C when the set temp. is 24°C or more
*
Set temp. when the set temp. is below 24°C
3 SUL : Super ultra low
*
Fig. 8-2-5 Cold draft preventing control
The outdoor unit controls the outdoor fan based upon
the operation signal sent from the indoor unit, and
also controls revolution speed of the compressor
motor.
The power coupler for 4-way valve is turned on, and
turned off in defrost operation.
1. Heating capacity control
Calculate the difference between temperature
detected by room temp. sensor every minute and
the set temp. set on "Temp. indicator" and varia-
tion amount of room temp.
Then, obtain the correction amount of the com-
mand signal, and correct the current frequency
command signal.
2. High-temp. release control
If temperature of the indoor heat exchanger
detected by the indoor heat exchanger sensor is
58°C or higher, compressor motor speed is
gradually lowered to prevent over-temp. rising of
compressed pressure.
If temperature becomes below 51°C, return to
above item 1.
3. Defrost control
HIGH
Approximate
revolution speed
of HIGH and SUL
linear by Tc.
3
*
SUL
SUL ( NOTE : * 1)
Stop
– 17 –
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1) Detection of frost
In heating operation, time duration while the
compressor operates is counted, and defrost
operation starts by any condition described
below.
a. The counted time is 28 minutes or more,
and status that temperature of the outdoor
heat exchanger detected by the outdoor
heat exchanger is –20°C or lower contin-
ued for 3 minutes or more.
b. The counted time is 28 minutes or more,
and status that temperature of the outdoor
heat exchanger detected by the outdoor
heat exchanger is –8°C or lower and
temperature lowered by 2.5 °C than the
minimum value of the outdoor heat ex-
changer during 10 to 15 minutes count time
continued for 3 minutes or more.
c. The counted time is 34 minutes or more,
and status that temperature of the outdoor
heat exchanger detected by the outdoor
heat exchanger is –5°C or lower and
temperature lowered by 3.0 °C than the
minimum value of the outdoor heat ex-
changer during 10 to 15 minutes count time
continued for 3 minutes or more.
d. The counted time is 4 hours or more, and
status that temperature of the outdoor heat
exchanger detected by the outdoor heat
exchanger is 0°C or lower and temperature
lowered by 1.0 °C than the minimum value
of the outdoor heat exchanger during 10 to
15 minutes count time continued for 3
minutes or more.
e. If the following three conditions are satis-
fied, defrost operation (Timer defrost) starts
after heating operation for 48 minutes.

Setting on remote controller, HEAT
(mode), HIGH (Fan), 30°C (temp.).
‚
Room temp. is 19°C to 24°C, and
outside air temp. is 5°C or lower.
ƒ
Defrost operation has been already
performed once.
2) Defrost operation
Operation of the compressor is stopped once,
turn off power coupler for 4-way valve after 10
seconds, and then exchange the
4-way valve.
After 20 seconds, restart operation of the
compressor. Turn off the outdoor fan just when
the compressor stopped.
If temperature of the indoor heat exchanger is
lower than settimg temperature, stop the
indoor fan.