Flooded type water cooled screw chiller (PCB Control) MCAC-CTSM-2012-11
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2) Miniature Circuit Breaker:
a) Protective condition: current passing the miniature circuit breaker exceeds its numerical
protection value;
b) Results of action execution: power-fail of corresponding circuit, failure of start, circuit breaker
switch positioned in the OFF terminal
c) Processing mode: inspect its rear end for burn-down of component(s) or short-circuit between
circuits. If any, please replace the component(s) or modify wiring;
You may attempt to set the circuit breaker to ON terminal, if it immediately trips once again, it
indicates that there is always a condition of short circuit, in this case, inspect the line and
components having not executed any action for short circuit until normal pull-in is available.
Notes: please switch on once without electricity prior to inspection. Damage to the miniature circuit
breaker itself is resulted from existence of heavy current shock. At this moment, switch-on is
impossible without electricity. When switch-on is successful, please test with a multimeter whether
breakover is completed, excluding the case that mechanical mechanism is normal but electric
mechanism is damaged. In such case, please replace the miniature circuit breaker, and inspect the
above steps.
3) Moulded Case Circuit Breaker
a) Protective condition: too heavy current of units or existence of short circuit failure of units
b) Results of action execution: complete power-fail
c) Processing mode: inspect whether the electric control part of units and insulation of loads are
normal, if yes, power on and start the units again, and measure whether the working current of
compressors and system pressure are normal
4) Compressor thermal relay
a) Protective condition: too heavy compressor current or existence of short circuit failure
b) Results of action execution: units stop, display of compressor overload on touch screen,
thermal overload relay trip, failure of start.
c) Processing mode: inspect whether the compressor part and insulation of loads are normal,
inspect the pressure value when an alarm is given, and balance the pressure if it exceeds the
running range. Please monitor the current of compressors in real time to ensure whether it is
within normal running after the compressor thermal relay is reset.
5) Sensor Failures
Sensor failures include short circuit and open circuit of the temperature sensor and the pressure
sensor (transformer). The current transformer is also included in the case of a stepless type
a) Protective condition: any sensor failure
b) Results of action execution: stop of units, display of corresponding sensor failure on touch
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