Flooded type water cooled screw chiller (PCB Control)
57
7.
Safety protection
Name
Code
Brand
Setting Range
Location
Low-pressure
Switch
YK-0.3/0.20-
O-R-7000
JUNLE
ON 0.10Mpa
OFF 0.20Mpa
High-pressure
Switch 1
YK-1.4/0.9-C-
R-7000
JUNLE
ON 1.4Mpa
OFF 0.9Mpa
Note: Manual reset is needed for high-pressure switch.
Safety Devices
Compressor protection module
The units are equipped with compressor protection modules built in the wiring cabinet of compressor.
INT69 HBY and JTX-A module is designed to detect the motor winding temperature, phase sequence
and phase loss. The detecting signal of JTX-A is voltage type. When motor winding temperature
reaches set point, the module will cut off control circuit immediately. The module with phase
sequence control can prevent motor reversal due to the adverse consequences. When any one
phase loses, the module will cut off main power after a short delay to protect the motor from burning.
When phase unbalance happens, it cuts the power immediately. In order to avoid interference and
discriminate between false voltage drop and malfunction as phase loss or phase unbalance during
motor operating, JTX-A will cut off main power after 3-5s delay.
Thermal overload relay
Each compressor is equipped with one thermal overload relay to protect the compressor against
overcurrent. Bypass the current transducers or make any changes to the factory default set points is
forbidden. The configuration of the module defines the Must Trip Amps (MTA) at which the thermal
overload relay will turn the compressor off.
