Toshiba MM-A0280HT Service Manual page 33

Item
1a. Electronic
expansion
valve (PMV)
control
1b. Pulse motor
valve (PMV)
control
11
2a. Outdoor fan
control
Outline of Control
Outdoor Unit
Operation explanation and applied data, etc.
(1) PMV A control (PMV x 2)
1) The PMV (pulse motor valve) is controlled
between 100 ~ 1000 pulses during the
operation.
2) The PMV is fully open during the cooling
operation (PMV A1 = 500 pulses,
PMV A2 = 500 pulses).
3) During the heating operation, the opening rate is
determined by the temperature which the TS/TD
sensor detects and the pressure rate which PS
detects (Super heat control).
4) The PMV is fully open when the thermostat is off,
when the operation is switched off or when the
operation is ceased under abnormal
circumstances.
1000
550
PMV
500
opening
rate
100
PMV A1
50
Min.
(1) PMV B control
The purpose of PMV B control is to control the liquid
refrigerant bypass by limiting discharge
temperature or compressor internal temperature
increase.
1) Opening is controlled with pulses from 0 ~ 500.
2) PMV opening is controlled with temp. detected
by TS/TD sensors.
3) PMV openings are fully closed during thermostat-
OFF, operation stop, and emergency stop.
(1) Cooling fan control
1) In a specified time when cooling operation is
activated, the master outdoor unit controls the
outdoor fan speed (no. of fan driving waves) by Pd
pressure. The slave outdoor unit controls the
outdoor fan speed with temperature detected by
TE sensor.
Pd pressure
(kgf/cm 2 G) 22
21
19
[ ]
Max.
18
16 waves
17
16
15
[-1 wave/20 sec ]
14
In down time:
From 15 waves to 1 wave
13
[
Interval [0 wave ]: 180 sec
12
control [1 wave ]:
11
* PD pressure is maintained between 14.5 ~ 18
kgf/cm 2 G by the cooling fan control. The no. of
waves can be controlled between 0 wave (STOP) to
16 waves (all waves).
PMV A2
Max.
Mid.
[+1 wave/20 sec ]
From 2 waves to
Max. no. of waves
[Hold ]
[+1 wave/20 sec ]
From 1 wave to
(Up to 5 waves)
Max. no. of waves
In up time:From 0 wave to 1 wave
]
30 sec
34
Remarks