Control Of The Cooling Cycle; Compressor Control - Hitachi SAMURAI Series Service Manual

2. Control Functions
Control of the cooling cycle

2.2 Control of the cooling cycle

2.2.1 Compressor Control

The compressor mounted on this product is equipped with a system to adjust the amount of discharge (slide valve). The
slide valve is installed on the screw rotor, and performs the adjustment of the amount of discharge with the change of
bypass amount by hydraulic activation.
In the case of load up
To suction side
Suction
gas
In case of load down
To suction side
Suction
gas
38
SMGB0097 rev.0 - 07/2015
Discharge
gas
Slide valve
Rotor
Solenoid valve (202)
Oil supply
Solenoid valve (201)
Oil supply
Bypass
Discharge
gas
Slide valve
Rotor
Solenoid valve (202)
Oil supply
Solenoid valve (201)
Oil supply
Cylinder part
Rod
Piston
Spring
Solenoid valve (203)
Cylinder part
Rod
Piston
Spring
Solenoid valve (203)
The solenoid valves for each operation are shown below:
Solenoid valve 201
Start up ON
Load up OFF
Load down OFF
Intermediate hold OFF
To suction side
To suction side
202 203
OFF OFF
OFF ON
ON OFF
OFF OFF