PARAMETER STATUS
ON/OFF | CONTROL | HEATING/COOLING | REMOTE HEATING/ | HC_SEL | OUTDOOR TEMPERATURE | OPERATING |
STATUS | TYPE | SELECTION IN | COOLING CONTACTS |
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| LOCAL MODE |
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Off | - | - | - | - | - | Cooling |
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On | Local | Cooling | - | - | - | Cooling |
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On | Local | Heating | - | - | - | Heating |
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On | Local | Auto | - | - | > Cooling threshold | Cooling |
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On | Local | Auto | - | - | < Heating threshold | Heating* |
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On | Local | Auto | - | - | Between cooling and heating thresholds | Standby |
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On | Remote | - | Cooling mode | - | - | Cooling |
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On | Remote | - | Heating mode | - | - | Heating |
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On | Remote | - | Auto mode | - | > Cooling threshold | Cooling |
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On | Remote | - | Auto mode | - | < Heating threshold | Heating* |
On | Remote | - | Auto mode | - | Between cooling and heating thresholds | Standby |
On | CCN | - | - | Cooling | - | Cooling |
On | CCN | - | - | Heating | - | Heating |
On | CCN | - | - | Auto | > Cooling threshold | Cooling |
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On | CCN | - | - | Auto | < Heating threshold | Heating* |
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On | CCN | - | - | Auto | Between cooling and heating thresholds | Standby |
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*Does not apply to cooling only units that do not control a boiler.
5.3 - Evaporator water pump control
The unit can control one or two evaporator water pumps. The evaporator water pump is turned on when this option is configured (see User configuration) and when the unit is in one of the on modes described above or in delay mode. Since the minimum value for the delay at
If two pumps are controlled and the reversing function has been selected (see User 1 configuration), the control tries to limit the pump run time delta to the configured pump change- over delay. If this delay has elapsed, the pump reversing function is activated, when the unit is running. During the reversing function both pumps run together for two seconds.
If a pump has failed and a secondary pump is available, the unit is stopped and started again with this pump.
The control provides a means to automatically start the pump each day at 14.00 hours for 2 seconds when the unit is off. If the unit is fitted with two pumps, the first pump is started on odd days and the second pump is started on even days. Starting the pump periodically for few seconds increases the
5.4 - Control interlock contact
This contact checks the status of a loop (water flow switch and customer safety loop, see section 3.6). It prevents the unit from starting if it is open when the delay at
5.5 - Evaporator antifreeze protection
The heater for the evaporator and water pump cycling (for units with a pump) can be energised to protect the evaporator, if it can be damaged by freezing, when the unit is shut down for a long time at low outdoor temperature.
NOTE: Evaporator heater control parameters can be modified, using the Service configuration.
5.6 - Control point
The control point represents the water temperature that the unit must produce. The inlet water is controlled by default, but the outlet water can also be controlled (requires a Service configuration modification).
Control point = active setpoint + reset
5.6.1 - Active setpoint
Two setpoints can be selected as active in cooling mode and three in heating mode. Usually, the second cooling setpoint is used for unoccupied periods or for ice storage (brine unit). The second setpoint in heating mode is used for unoccupied periods, and the third heating setpoint is used for holiday periods or public holidays. Depending on the current opera- tions, the active setpoint can be selected by choosing the item in the Information menu, with the user’s
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