Safety switches
If any problems occur, the following safety switches stop the absorption chiller safely.
Table 25: Safety switches
Safety switch name Location Symbol Operation
Chilled water differential pressure
switch
See Figure 69
69WC1 Operates when the flow rate lowers.
Solution circulating pump thermal
switch
Th1
Solution spray pump thermal switch Th2
Refrigerant pump thermal switch
In control panel
Th3
Operates when the current rises higher than the
set value.
Chilled water overcooling switch 26WL
Operates when the chilled water outlet
temperature falls lower than the set value.
Refrigerant overcooling switch 26RL
Operates when the refrigerant temperature falls
lower than the set value.
Solution high temperature switch
Soft switch
of sequencer
26SH1
Operates when the solution temperature in the
generator rises higher than the set value.
Control switches:
ON/OFF operation control switch 23AS
Turns OFF when the chilled water temperature
at the outlet falls lower than the set value and
turns ON when the chilled water temperature
rises higher than the set value.
Purging tank pressure switch
Soft switch
of sequencer
63AP
Operates when the pressure in purging tank rises
higher than the set value.
Level switch for evaporator tank
See Figure 69
LVS
Operates when the refrigerant level in evaporator
is low.
Sensors and gauges:
Generator pressure gauge PG1
Purge tank pressure gauge PG2
Purge tank pressure transmitter PT1 Detection of pressure of purge tank
Pt100 Ω for chilled water inlet
temperature
TE1 Detection of temperature at each part
Pt100 Ω for chilled water outlet
temperature
TE2
Thermocouple for cooling water inlet
temperature
TE3
Thermocouple for cooling water
outlet temperature
TE4
Pt100 Ω for refrigerant temperature TE5
Thermocouple for absorber solution
temperature
TE6
Thermocouple for generator solution
temperature
See Figure 69
TE7
Generator pressure transmitter PT2
141YHAU-C Single Effect Steam-Fired Absorption Chiller