Hitachi SAMURAI Series Service Manual page 58

2. Control Functions
Control of the cooling cycle

Defrosting operation flow
No
Tr < 0ºC
Yes
Fan stop (0Hz) order
50
SMGB0082 rev.1 - 07/2015
Fulfilment of conditions
to start defrosting
Compressor capacity control hold
10 seconds count
Fan 0 Hz order. Switching of
4-way valve
10 seconds count
Inlet refrigerant temperature of water-
side heat exchanger (Tr ≤ 0ºC
No
Tr ≤ 2ºC
No
Capacity control hold
1 minute has passed
since start of defrosting
Yes
Yes
During fan operation
Tr > 5ºC
Pd ≥ 1.1 MPa
Yes
Fan operation start
Yes
Compressor load down output
(5 seconds output)
Yes
Compressor load up output
(5 seconds output)
No
Yes
Pd ≥ 1.4 MPa
7 minutes
Yes
have passed since
start of defrosting
No
No
Fulfilment of conditions
to finish defrosting
(next page)
No
No