LG LCWW, Operation & Maintenance Manual

Page: 20 / 119

20
3. STRUCTURE OF SCREW CHILLER
ENGLISH
The following devices are installed for safe operation and equipment protection(1 cycle).
Safety devices
No. Item
Installed
location
Measurement
objects
Contents
Quan-
tity
1
Chilled water
low temp.
Chilled water
inlet nozzle
Chilled water inlet
temp.
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.
1
2
Evaporator re-
frigerants low
pressure (low
temperature)
Evaporator
shell
Evaporation
pressure (temp.)
If the pressure in the evaporator becomes lower
than the value in the table below, the chiller will
stop.
1
3
Condenser
high pressure
(high tempera-
ture)
Condenser
shell
Condensing
pressure (temp.)
If the pressure in the condenser becomes higher
than the value in the table below, the chiller will
stop.
1
4
Evaporator re-
frigerant low
temperature
Evaporator
inlet
Evaporator
refrigerant temp.
When evaporator pressure is used to protect
compressor motor, and the temperature drops to
1.5 °C or below, the chiller will stop
1
5
Compressor
discharge high
temperature
Compressor
outlet
Compressor dis-
charge temp.
If compressor discharge gas temperature be-
comes 100 °C or higher, the chiller will stop.
1
6
Refrigerant
high/low pres-
sure difference
low
Evaporator
shell, Con-
denser shell
Pressure difference
between Evapora-
tor/Condenser
If the pressure difference is smaller than 4 bar,
the chiller will stop.
1
7
Chilled water
pump problem
Chilled water
header
Chilled water loss
head
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.
1
8
Cooling water
pump problem
Cooling water
header
Over-current
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.
1
9
Current limit
function
Control panel Motor current
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 .
1
Standard setting 1.90kg/cm
2
Standard setting 10.10kg/cm
2