Protection Control - Sanyo SPW-CR363GVH8 Service Manual

1. Compressor Control

1-2. Protection control

(1) Main principles
If the current capacity decreases, it does not increase again for 3 minutes.
(2) Evaporation temperature control (Freeze prevention)
1
Of the E1 and E2 indoor coil temperature of all the thermo-on indoor unit operating in cooling mode. The
lowest is taken as the minimum evaporation temperature (=Te) and the control indicated below is performed
every 30 seconds.
Minimum evaporation
temperature (Te)
2
2
When TEST RUN selected for even one of the indoor units operating in cooling mode, the current capacity is
always allowed to increase.
3
For 3 minutes after the compressor start, the "current capacity decrease 1 step" is the "current capacity
increase inhibited".
4
At the minimum current capacity, if evaporation temperature control requires further current capacity decrease,
it is treated as current capacity increase inhibited for 10 minutes and the unit does not thermo-off.
(3) Condensation temperature control
1
Of the E1 and E2 indoor coil temperatures of all the connected indoor units, the highest is taken as the
maximum condensing temperature (=Tc) and the control in the table below is performed. This control is
performed every 15 seconds.
Note : The value N is changed 60~63 °C according to operating condition. (Normally 63 °C)
Minimum condensation
temperature (Tc)
2
At the minimum current capacity, if condensation temperature control is on "current capacity decreases 1
step", it is treated as "current capacity increase inhibited" for 10 minutes and the unit does not thermo-off (10-
minute timer). When this 10 minutes is up, if the condensation temperature control is still on "current capacity
decreases 1 step", the unit will thermo-off. However, if the maximum condensation temperature is N + 0.5 ˚C
or higher, the unit stops operation immediately. The 10-minute timer is cleared if the control is moved into any
area other than "current capacity decreases 1 step" or if all the compressors are stopped.
↑
Current capacity increase allowed
5.5 ˚C
5.0 ˚C

Current capacity increase inhibited
1.5 ˚C
1.0 ˚C
Current capacity decreases 1 step
↓
↑
Thermo-off
N + 0.5 ˚C
N

Current capacity decreases 1 step
57.5 ˚C
57.0 ˚C
 Current capacity increase inhibited
50.0 ˚C
49.5 ˚C
Current capacity increase allowed
↓
Control
Control
II - 4
Processes and Functions
SM830063