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Flooded type water cooled screw chiller (PCB Control)
MCAC-CTSM-2012-11
27
3. Control Flow Chart
Guidance of common electric problems treatment:
1) Phase
sequence protector:
a) Protective
condition: anti-phase,
phase lack, overvoltage, under voltage or
imbalance
of three-phase voltage of power input terminal of phase sequence protector;
b) Results of action execution: power module failure lamp is ON, touch screen displays power
failure and fails to be started;
c) Processing mode: see the power module, exchange any two unit incoming lines if it is
anti-phase;
Please do not start until power gets right with failure removed in case of other failures.
Notes: this module has the important action of compressor protection. The imbalance rate of voltage of
current is usually specified by compressor manufacturers, and burn-down due to overheating will be
resulted from long-time operation under abnormal working voltage. The value and replacement of a
scroll compressor cannot beat those of a screw compressor. There are more complaints, most of which
concerned with normal protection, with respect to this problem when integrated with the current market
feedback.
Moulded Case
Circuit Breaker
Phase Se
qu
en
ce
Miniature
Circuit
Breaker
M
~
Compressor
Thermorelay
Compressor
Contactor
Star-Delta Start
星三角启动
PC Board
HMI
Terminal for
External Signal
e.g. Temp.
Pressure
Terminal for
Output Action
e.g. Solenoid
Valve
Input
terminals
Output
terminals
Commu
nication
Moulded Case
Circuit Breaker
M
~
Compressor
Thermorelay
Compressor
Contactor
Star-Delta Start
380VAC
3P+N+PE
2 Compressors
Double-Head