Parts Control - Midea LSBLG MCF Series Technical & Service Manual

MCAC-CTSM-2018-1
temperature thermistors are installed in wells on chilled water inlet/outlet and cooling water inlet/outlet.
Refer to the electric control wiring diagram for detailed connection information.
 Thermistor replacement
To Replace Thermistors RT1, RT2, RT3, RT4, RT5, or RT6 (Entering/Leaving chilled Water;
Entering/Leaving cooling Water; Discharge Temperature; Oil temperature) — Disconnect appropriate
connector from the PCB controller. New thermistors should be spliced to existing wiring close to the
connector unless new connectors are required. Remove thermistor cable from harness. Remove and
discard original thermistor from well. Insert new thermistor in well body to its full depth. Add a small
amount of thermal conductive grease to thermistor probe and well. Tighten the screw to prevent
thermistors from slipping out of the well.
 To Service Compressor Motor Thermistors
A thermistor is factory installed in each compressor. Connections for the thermistors are located in the
compressor wiring box. 2 terminals are reserved for the thermistor: S1 and S2. Motor temperature is
measured by leads connected to S1 and S2 terminal. The thermistors are not serviceable in the field. If
the compressor motor thermistor fails, replace the compressor.
2).pressure sensors
The pressure sensors are pressure transmitters. Danfoss AKS3000 are used.
Water temp. thermistor
5.

Parts control

1). Oil heater control
If the unit is in standby modes and, the oil heater is energized to keep normal oil temperature. When
the unit starts, the oil heater it is turned off.
Oil heating time limits:

When cooling water inlet temperature≥ 35° C (real time value), oil heating time for first startup
is 0.5h. If power down happens when the unit is running and downtime is less than 8hrs, no
heating time delay is needed when unit restarts. If it exceeds 8hrs, 0.5h heating time is needed.

When cooling water inlet temperature ≥ 30° C (real time value), oil heating time for first startup
is 1h. If power down happens when the unit is running and downtime is less than 5hrs, no
heating time delay is needed when unit restarts. If it exceeds 5hrs, 1h heating time is needed.

When cooling water inlet temperature ≥ 25° C (real time value), oil heating time for first startup
is 2hrs. If power down happens when the unit is running and downtime is less than 3hrs, no
heating time delay is needed when unit restarts. If it exceeds 3hrs, 1h heating time is needed. If
Flooded type water cooled screw chiller (MIC)
suction temp. thermistor
31
pressure transmitter AKS3000