41
11
Outline of Control
Outdoor Units
14. IDU
exchanger
heat removal
(1) To prevent the IDU heat exchanger remaining hot
after operation has stopped the indoor fan operates
in low fan speed for approximately 30 seconds.
Item
Operation explanation and applied data, etc.
Remarks
13. Cold draught
prevention
control
3) For the slave outdoor units
• The compressors 1 and 2 are kept on. Should
they be off they will be switched on.
• After the signal to finish the defrost operation
is received from the master outdoor units, the
4-way valves become switched on.
• The capacity of the compressors is controlled
according to the on/off signals from the master
outdoor units thereon.
(5) SV41, 42 low-pressure release control
This prevents the low-pressure level relaxing during
the defrost control operation. The master outdoor
units and slave outdoor units have their own control
over this action when the defrost/heating operation
is in progress.
1) Control details
When PS pressure
≤
0.5 kgf/cm
2
G, the control
switches SV41 and SV42 on.
When PS pressure
≥
1.0 kgf/cm
2
G, SV41, and 42
are switched off.
(1) During the heating operation, the indoor fan is
controlled according to the temperature that is
detected by TC2 (indoor heat exchange sensor).
• "Preheat defrost"
light displayed
A zone: set fan operation
from the remote
controller
B zone: low fan speed
C zone: OFF
(°C)
30
26
20
16
A
B
C
12. Defrost
control
(reverse
defrost
method)
Summary of Contents for MM-A0160HX
Page 1: ...Service Manual Air Conditioner Multi Split Type System Modular Multi System HFCR407C A90 0130 ...
Page 2: ......
Page 133: ...134 20 Additional Literature and Contacts ...
Page 134: ...135 20 Additional Literature and Contacts ...
Page 135: ...TOSHIBA AIR CONDITIONING www toshiba aircon co uk MADE IN UK A90 0130 Revised April 2001 ...