1592015820 User manual IC260_261L_D DUO FW1.9 rel. 1.0
Pag. 65 of 149
PUMP DOWN with low pressure probe
CO36 = 1 Pump down enabled during the switching off (low pressure probe)
Before turning off the last compressor, the solenoid valve is closed; the compressor works until the pressure
falls below CO37 or after a maximum time CO39; in this case an alarm is displayed (b1PH or b2PH) but the
machine continuous to work as normal.
If the alarm occurs more than AL21 times per hour, the Ichill generate a manual alarm.
Low pressure alarm (when the low pressure switch is used) is disabled for AL02 time after valve activation
(AL02=0 the alarm is disabled when the compressor is OFF).
When the first compressor of the circuit is switched on, the solenoid valve is switched on 1 seconds before it.
CO35 = 2 Pump down enabled during the switching off and switching on (low pressure probe)
Before turning off the last compressor, the solenoid valve is closed; the compressor works until the pressure
falls below CO37 or after a maximum time CO39; in this case an alarm is displayed (b1PH or b2PH) but the
machine continuous to work as normal.
If the alarm occurs more than AL21 times per hour, the Ichill generate a manual alarm.
Low pressure alarm (when the low pressure switch is used) is disabled for AL02 time after valve activation
(AL02=0 the alarm is disabled when the compressor is OFF).
When the first compressor of the circuit is switched on, the solenoid valve is switched on 1 seconds before it.
When the first compressor of the circuit is switched on, the solenoid valve is switched on 1 seconds before it
if the pressure is higher than CO37 + CO38.
If the pressure remains lower than CO37 + CO38 the compressors does not restart and after CO39 time a
pump-down alarm is displayed.
The parameter AL23 allows to choose if the pump down alarm (during the switching on) is automatic or
manual reset:
AL23 =0 automatic reset; the compressor will rester when the pump down pressure switch is active
AL23=1 manual reset; if the number of pump down alarm per hour is lower than AL22 the reset is
automatic, manual reset; if the number of pump down alarm per hour is higher than AL22 the reset is
manual
CO36 = 3 Pump down enabled during the switching off only in chiller mode(low pressure probe)
The pump douwn procedure works as CO36=1 but only in chiller mode; in heat pump mode the solenoid
valve is activated when the first compressor is ON and de-.activated when the last compressor is OFF.
CO36 = 4 Pump down enabled during the switching off and switching on only in chiller mode (low
pressure probe)
The pump douwn procedure works as CO36=1 but only in chiller mode; in heat pump mode the solenoid
valve is activated when the first compressor is ON and de-.activated when the last compressor is OFF.
ATTENTION
If the pump down function is enabled, during the unit start-up from digital input as pump down
pressure switch and also from analogue input as low pressure transducer, the compressor will
restart only if both the inputs are satisfied.
Pump Down by TIME
The pump down can be enabled also by time; in this case the compressor is activated after CO58 from
solenoid valve switching on and de-activated after CO59 from solenoid valve switching off.
CO 58
Maximum time for the activation of the pump-down during the
switching off
CO58 = 0 Not enabled
0
250
Sec
CO 59
Maximum time for the activation of the pump-down during the
switching on
CO59 = 0 Not enabled
0
250
Sec
