LG RCWW Operation & Maintenance Manual page 71

Classification Contents
Prevent Condenser
high pressure
Prevent Evaporator
low pressure
Prevent Evaporator
Preventive
refrigerant low tem-
control
perature
Prevent Compressor
discharge high tem-
perature
Motor over-current
preventive control
Classification
Motor status contact - Open
Motor over-current abnor-
mal contact - Open
External fault signal con-
tact – Closed
Switch
Startup failure
contact
Delta contactor (during oper-
ation)- Open
Oil level switch – Open
Refrigerant pressure
switch – Open
Close guide vane when Condenser
pressure is above High pressure
prevention set value +(100-set
value)/2 삭제
Close guide vane when Evaporator
pressure is below Low pressure
prevention set value -(100-set
value)/2 삭제
Close guide vane when Evaporator
temperature is below Low temper-
ature prevention set value -(100-set
value)/2 삭제
Close guide vane when Evaporator
temperature is above High temper-
ature prevention set value +(100-
set value)/2 삭제
Close guide vane to lower the cur-
rent below the set value when
Compressor motor current reaches
*105% of the set value 삭제
Contents
Motor status contact(MP) -
Open
Motor over-current abnor-
mal contact (X1) - Open
External fault signal contact
(E-SP) – Closed
Compressor startup com-
plete input signal - None
Starter Panel
contactor(KM3) (during Op-
eration) - Open
Oil level switch(OL) – Open Chiller stop
Refrigerant pressure
switch(PS) – Open
Table 10 Protection logics
Cause
Display caution message for
Condenser high pressure
preventive control
Display caution message for
Evaporator low pressure
preventive control
Display caution message for
Evaporator refrigerant low
temperature preventive con-
trol
Display caution message for
Compressor discharge high
temperature preventive con-
trol
Display warning message
for Compressor motor over-
current preventive control
Cause
Chiller stop
Chiller stop
Chiller stop
Chiller stop
Chiller stop
Chiller stop
4. CONTROL SYSTEM
Operation Status
Caution
Caution
Caution
Caution
Caution
Operation Status
Problem
Problem
Problem
Problem
Problem
Problem
Problem
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