1652H4A02 Ed.09
14
Cold regulation
Solenoid control (COOL Relay)
Cold production is regulated by means of opening /
closing the solenoid valve.
When the temperature in probe S1 reaches the set
point (
SP
) value plus the probe's differential (
C1
), the
solenoid opens and causes the temperature to drop.
Once the set point (
SP
) value is reached, the solenoid
closes.
Compressor control (Relay AUX 1)
With Pump Down (
Inl:
2, 5, 7)
Requires the connection of a low pressure
switch in digital input 1.
When the temperature in probe S1 reaches the set
point (
SP
) value plus the probe’s differential (
C1
), the
solenoid opens, causing the pressure in the evaporator
to increase and, therefore, the low pressure switch
deactivates and the compressor starts up.
Once the set point (
SP
) value is reached, the solenoid
closes, causing the pressure in the evaporator to
decrease, triggering the low pressure switch and
stopping the compressor.
For further details of the process, see the next page.
Without Pump Down (
Inl:
3, 6, 8,)
The compressor operates simultaneously with the solenoid valve, starting up when the latter opens and stopping
when it closes.
Operation in the event of a fault in probe S1
If probe S1 fails (fault, disconnection, etc. ), compressor behaviour will depend on parameter
C6
, with one of 3
options available:
C6=0:
The compressor is stopped until probe S1 begins to operate again.
C6=1:
The compressor is started-up until probe S1 begins to operate again
C6=2:
The compressor operates in line with the average operation during the 24 hours prior to the error,
taking into account the number of start-ups and stops and the average time in each state (stop-start).
If 24 hours have not elapsed without a probe error, the device moves to
C6=3
mode.
C6=3:
C6=3: The compressor operates in line with the times programmed in
C7
(ON) and
C8
(OFF).
SP+C1
SP+C1
SP
SP
Solenoid
Solenoid
Low
pressure
switch
Compressor
Compressor
ON
ON
ON
ON
ON
ON
C7
C7
C8
S1
S1
