4 Troubleshooting
Protection control function
4.4 Protection control function
This Chiller unit is provided with protection control functions to release abnormal statuses before reaching alarm because
of abnormality occurrence.
Name of
protection control
Conditions for operation
(Compressor
frequency control)
I1 > Setting value×0.97
Overcurrent
protection
I1 > Setting value
(Unit current)
* I1: Unit current
Pd-Ps ≤ 0.3MPa
Pd-Ps ≤ 0.25MPa
Differential
Pressure Protection
* Pd: High pressure
Ps: Low pressure
Twp ≤ 2ºC
Outlet water
temperature
Twp ≤ 1.5ºC
decrease
* Twp: outlet water
prevention
temperature (Protection)
Cooling
Pd ≥ 1.41MPa
Pd ≥ 1.44MPa
*Pd: high pressure
Discharge pressure
over-increase
prevention
Cooling/Heating
Pd ≥ 1.84MPa
Pd ≥ 1.87MPa
*Pd: high pressure
Water-cooled systems
(Cooling only)
Suction pressure
Ps < 0.18MPa
decrease
prevention
Ps < 0.14MPa
* Ps: low pressure
Cooler inlet
refrigerant
Tr < -4ºC
temperature
* Tr: cooler inlet refrigerant
decrease
temperature
prevention (at
cooling operation)
92
SMGB0120 rev.0 - 11/2017
Description of control
Release conditions
I1 < Setting
Load up prohibition
value×0.95
Forced load down
I1 < Setting
value×0.98
60 seconds passed
Load down prohibition
and Pd-Ps > 0.3MPa
Forced load up
Ps > 0.3MPa
30 seconds passed
Load up prohibition
and Twp > 2ºC
Forced load down
Twp > 2ºC
Cooling
10 minutes have
Load up prohibition
passed or
Pd ≤ 1.39MPa
Forced load down
Pd ≤ 1.41MPa →
To Control
Cooling/Heating
10 minutes have
Load up prohibition
passed or
Pd ≤ 1.82MPa
Forced load down
Pd ≤ 1.84MPa →
To Control
Water-cooled systems
(Cooling only)
Load up prohibition
Ps < 0.20MPa
Forced load down
Ps < 0.16MPa
Load up prohibition
60 seconds passed
Display
LCD
Segment
Current
limited
Differential
pressure
limited
Outlet water
temperature
limited
High
pressure
over-increase
limited
High
pressure
over-increase
limited
Low pressure
decrease
limited
Cooler
refrigerant
temperature
limited