Panasonic CS-VA70KE Service Manual page 25

8.3.8. Deicing Control
Deice operates to prevent frosting at outdoor heat exchanger.
· Normal Deicing
Deice operation detection commences after 30 minutes of Heating operation or 60 minutes after previous deice operation.If the
TRS (Thermal Reed Switch) senses the outdoor piping temperature drops to -3 °C (TRS CLOSE)
or less for 50 sec.continuosly during compressor is in operation, deice will start.
(There is no detection during Outdoor Fan stops.)
· Overload Deicing
During heating operation, if the outdoor Fan OFF duration (due to overload control) is accumulated up to 60 minutes and 1
minute after the compressor starts, deicing starts.
· Deicing ends when
1. 12 minutes after deicing operation starts;
2. TRS senses the outdoor piping temperature rises to 4 °C (TRS OPEN).
3. Deicing will not end immediately as time delay (Td) is valid as shown below.
· Once deicing operation starts, it will not end for 60 seconds.
· After deicing operation, compressor stops for 30 seconds and 4-way valve stays at cooling position for 10 seconds.
Time taken from deicing start to TRS OPEN (T)
T 3 minutes
3 minutes T 6 minutes
6 minutes T 9 minutes
T 9 minutes
CS-VA70KE / CU-VA70KE / CS-VA90KE / CU-VA90KE / CS-VA120KE / CU-VA120KE
25
Td (seconds)
0
60
120
180