LCP
RG66006889-Rev.01
26
TABLE II – SETTING OF SAFETY - CONTROL DEVICES
- LCP SERIES
CONTROL DEVICE
ACTIVATION
DIFFERENTIAL
RESETTING
Antifreeze thermostat
°C
+4
1
Automatic
Safety maximum pressure switch
bar
45
-13,5
Manual
Safety maximum pressure switch
bar
40,5
-12,2
Manual
High pressure relief valve
bar
-
-
-
Minimum pressure switch
bar
1,5
+1,0
Automatic
Modulating condensation control device
bar
18
10
Time lapse between two starts of the same
compressor
s 450 -
-
Delay in flow switch alarm
s
20
-
-
Delay in low pressure alarm
s
1
-
-
Pump rotation [optional]
h
6
-
-
End-of-defrost pressure
bar
29
-
-
Maximum defrost time
s
360
-
-
Minimum time lapse between two
defrosting operations
s 1800 -
-
9.2
MAXIMUM PRESSURE SWITCH
The high pressure switch is of the manually reset type and classifiable as category IV under EEC 97/23.
It directly stops the compressor when the discharge pressure exceeds the set value (see section 5.4).
To verify its efficiency, while the compressors are running, close off the passage of air into the
condensers and check by referring to the compressor outlet pressure gauge (previously installed)
whether the pressure switch trips (i.e. the compressors stop) when the set value is reached.
Warning: during this operation, if the safety device fails to trip, the second cascade-
connected pressure switch will step in to shut down the unit; in any event, however, you
should be ready to shut off the unit as directed in the section "Stopping the Unit" – see
also section 5.4.
The high pressure switch must be
manually
reset; this is possible only when the pressure falls below the
set differential (see Table II).
9.3
MINIMUM PRESSURE SWITCH
The low pressure switch stops the compressor when the intake pressure falls below the set value for
more than 60 seconds.
The switch is automatically reset when the pressure rises above the set differential (see Table II);
however, the unit will not resume operation until the alarm memory on the microprocessor control is
cleared.
9.4 SERVICE
THERMOSTAT
The function of this device is to start and stop the compressors according to the demand for chilled
water, as determined by a sensor placed at the evaporator inlet [water returning from the circuit].
This device is a function included in the microprocessor control and works with a proportional band width
that may be set as desired.
