Safety Protection - Midea LSBLG MCF Series Technical & Service Manual

Flooded type water cooled screw chiller (MIC)
7.

Safety protection

Name
Low-pressure
Switch
High-pressure
Switch 1
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.
sequence control can prevent motor reversal due to the adverse consequences. When any one
phase lost, the module will cut off main power after a short delay to protect the motor from burning.
When phase imbalance happens, the power cuts immediately. To avoid interference and discriminate
between false voltage drop and malfunction as phase loss or phase imbalance when motor is
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. Bypassing 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.
Code Brand
YK-0.3/0.20-
JUNLE
O-R-7000
YK-1.4/0.9-C-
JUNLE
R-7000
Setting Range Location
ON 0.10Mpa
OFF 0.20Mpa
ON 1.4Mpa
OFF 0.9Mpa
52
MCAC-CTSM-2018-1
The module with phase