LG RCWW Operation & Maintenance Manual page 20

3. STRUCTURE OF SCREW CHILLER
20
Safety devices
The following devices are installed for safe operation and equipment protection(1 cycle).
No. Item
Chilled water Chilled water
1
low temp. inlet nozzle
Evaporator re-
frigerants low Evaporator
2
pressure (low
temperature)
Condenser
high pressure Condenser
3
(high tempera-
ture)
Evaporator re-
Evaporator
4 frigerant low
temperature
Compressor
Compressor
5 discharge high
temperature
Refrigerant
Evaporator
high/low pres-
6 shell, Con-
sure difference
denser shell
low
Chilled water Chilled water
7
pump problem
Cooling water Cooling water
8
pump problem
Current limit
9 Control panel
function
Installed Measurement
location objects
Chilled water inlet
temp.
Evaporation
shell pressure (temp.)
Condensing
shell pressure (temp.)
Evaporator
inlet refrigerant temp.
Compressor dis-
outlet charge temp.
Pressure difference
between Evapora-
tor/Condenser
Chilled water loss
header head
Over-current
header
Motor current
Contents
This function stops the chiller when chilled water
outlet temp. becomes 2.9°C or less to avoid the
danger of freezing of chilled water.
Never change this setting.
If the pressure in the evaporator becomes lower
than the value in the table below, the chiller will
stop.
Standard setting
If the pressure in the condenser becomes higher
than the value in the table below, the chiller will
stop.
Standard setting
When evaporator pressure is used to protect
compressor motor, and the temperature drops to
1.5 °C or below, the chiller will stop
If compressor discharge gas temperature be-
comes 100 °C or higher, the chiller will stop.
If the pressure difference is smaller than 4 bar,
the chiller will stop.
When the chilled water flow amount passing
through evaporator tubes decreases and if water
head loss becomes less than the set value, the
chiller will stop.
When the cooling water flow amount passing
through condenser tubes decreases and water
head loss becomes less than the set value, the
chiller will stop.
Compressor motor current is measured, and ac-
cording to the excess percentage over the set
current value, different ignore times are applied,
and the chiller stops accordingly .
Quan-
tity
1
1
2
1.90kg/cm
1
2
10.10kg/cm
1
1
1
1
1
1