dixell ichill IC260L, Руководство пользователя

Страница: 71 / 105

1592015300 User manual iCHILL 200 L GB r1.3 09/09/2005
Pg.
70/105
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.
29.5 P
UMP
D
OWN ALARM DURING COMPRESSORS SWITCHING OFF
ACTIVATION
If within the time delay CO39 (maximum pump down duration in off) the low pressure switch or the pump down pressure switch is not
active or the pump down setpoint is not reached, the last compressor is switched off. In this case after this timeout the instrument
signals the B1PH or 2 alarms, in both cases when active the compressor is stopped.
The alarm can be:
•
with Automatic Reset that is not logged, the buzzer and alarm relay are not activated.
•
with Manual Reset that is logged, the buzzer and alarm relay are activated.
The Parameter
AL21 determines the number of pump down alarm events to turn from automatic to manual reset
The Reset is always manual if AL21 = 0.
The Reset is always automatic if AL21 = 16.
The reset becomes manual after AL21 = 1 ..15.
RESET
•
The Automatic Reset is activated when the next compressor thermoregulation is requested, in this case the pressure condition of
the pump down must be satisfied.
•
The Manual Reset needs to enter the function Menu under the AlrM label. After the reset the next thermoregulation restarts if the
pump down pressure is in normal condition.
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.
29.6 P
UMP
D
OWN INFORMATION
ATTENTION
SELECTION OF THE COMPRESSOR (for pump down in switching off)
Eg: Unit with 2 circuits and 3 compressors each.
Having an active digital input as remote off: if the compressor running hours are the same for all the compressors the unit will use the 1
st
compressor of the 1
st
and the 2
nd
circuit: therefore the number 1 and 4.
If the running hours are not equal for all compressors the unit will use the compressor having the less running time, this for any circuit
configuration.
During the pump down process the led of the running mode (chiller / heat pump) is blinking, while if one of the circuits are disabled from
the keyboard the running mode led is not blinking.
30 UNLOADING
30.1 H
IGH TEMPERATURE OF THE EVAPORATOR WATER INLET
The function is always enabled in chiller mode if there are at least 2 steps of power (two compressor or 1 compressor with partialization)
per circuit.
It is used to run the unit with high temperature of the evaporator water inlet (such as during the hot summer) to avoid a possible high
pressure alarm event.
The function si managed through an analogue input configured as NTC evaporator water inlet.
30.2 U
NLOADING DESCRIPTION
UNLOADING ACTIVATION
When the thermoregulation request begins to start the compressors in chiller mode, if the evaporator water inlet is equal or bigger than
the CO40 setpoint for the CO42 time.
When the unloading is active the display shows the AEUn blinking message alternated with the selected display measurement, the unit
will start with the loads selected with the CO49 parameter.
EXAMPLE
Unit with 2 circuits with 3 compressors each circuit.
If Par. CO49 = 2, 2 power steps per circuit, in case of unloading there will be 4 compressor running.
UNLOAD DEACTIVATION
If the temperature decreases under the value determined by (CO40-CO41) setpoint – differential, the unloading is disengaged, the
compressors are all available for the thermoregulation.
30.3 U
NLOADING
I
NFORMATION
If the temperature does not decrease enough to reach the CO40-CO41 value, under the CO40 setpoint the CO43, unloading timeout,
will start counting and when expired the unit will force the unloading off.