Installation and operation manual
21
EWAQ016~064BAW + EWYQ016~064BAW
Packaged air-cooled water chiller
4PW70082-1C – 2013.07
■ [8-04] Freeze-up prevention
The unit has a freeze-up prevention functionality for which
3 levels can be selected:
■ [8-04]=0 prevention level 0 (default: no prevention)
■ [8-04]=1 prevention level 1
■ [8-04]=2 prevention level 2
The freeze-up prevention is only active when the unit is in
thermo OFF condition. If prevention level 1 is enabled, the
freeze-up prevention will start if the outdoor ambient
temperature <4°C and if leaving or return water temperature
<7°C. For prevention level 2, the freeze-up prevention will start
as soon as the ambient temperature <4°C.
For both cases the pump will operate and if leaving or return
water <5°C for 5 minutes the unit will start up to prevent too low
temperatures.
This function can be enabled when there is no optional heater
tape or glycol in the system and when heat can be used from an
application.
[9] Automatic temperature compensation
If needed, it is possible to adjust some thermistor value of the unit by
a correction value. This can be used as countermeasure for
thermistor tolerances or capacity shortage.
The compensated temperature (= measured temperature plus
compensation value) is then used for controlling the system and will
be displayed in the temperature read-out mode.
■ [9-00] Leaving water temperature compensation value for
heating operation.
■ [9-01] Leaving water thermistor auto corrective function.
When enabled, this function will take into account the outdoor
ambient conditions and correct the measured value which will be
used for the logic.
Eg. when the ambient temperature is high during cooling mode,
the logic will correct the measured value of the leaving water
thermistor to a lower value to take into account influence of high
ambient temperatures in the measurement.
■ [9-02] Setting is not applicable
■ [9-03] Leaving water temperature compensation value for
cooling operation.
■ [9-04] Setting not applicable
[A] Option setup
■ [A-00] Setting is not applicable.
■ [A-01] Setting is not applicable.
■ [A-02] Setting is not applicable.
■ [A-03] Leaving water temperature overshoot/undershoot value
This setting makes it possible to set the allowable overshoot
(heating)/undershoot (cooling) when operating the unit during
leaving water control.
■ [A-04] Glycol concentration setting
This setting is only applicable for units with a low temperature
cooling option.
When changing this setting, the freeze prevention parameters
will be changed in relation with the glycol concentration.
■ [A-04]=0= 30% glycol, minimum leaving water=0°C
■ [A-04]=1= 40% glycol, minimum leaving water=–10°C
To set leaving water temperatures <0°C see "[6-03] Negative
leaving water temperature setting" on page 20.
[b] Settings are not applicable
[C] Leaving water temperature limits
■ [C-00] Maximum leaving water set point in heating operation
■ [C-01] Minimum leaving water set point in heating operation
■ [C-02] Maximum leaving water set point in cooling operation
■ [C-03] Minimum leaving water set point in cooling operation
(depends on [A-04] Glycol concentration setting)
■ [C-04] Setting is not applicable.
[d] Settings are not applicable
[E] Service mode
■ [E-00] Setting is not applicable.
■ [E-01] Setting is not applicable.
■ [E-02] Setting is not applicable.
■ [E-03] Setting is not applicable.
■ [E-04] Pump only operation (air purge function)
When installing and commisioning the unit it is very important to
get all air out of the water circuit.
Through this field setting the pump can be operated without
actual operation of the unit. By doing so this will enhance the air
removal from the unit.
■ [E-04]=0 normal operation of the unit (default).
■ [E-04]=1 program 1 the unit will perform the automatic air
purge operation for 108 minutes.
■ [E-04]=2 program 2 the unit will perform the automatic air
purge operation for 48 minutes.
[F] Settings are not applicable
CAUTION
Glycol concentrations lower than the set parameter
will cause freezing of the liquid.
[E-04]=1
▼
108 minutes
Pump operation for 10 minutes
▲
▼
Pump stops operation for 2 minutes
[E-04]=2
▼
48 minutes
Pump operation for 10 minutes
▲
▼
Pump stops operation for 2 minutes
4PWEN70082-1C.book Page 21 Wednesday, September 25, 2013 7:31 AM
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