VERDER CARBOLITE GERO HTF 18/27, Installation, Operation And Maintenance Instructions

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3.0 3508 Controller
To alter parameters or segments of an operating program, this program must be held
or reset. Press RUN/ HOLD to pause the program, or press RUN/ HOLD for 2 seconds to
reset.
3.8.2 Holdback
Holdback can be used to prevent the program from operating ahead of the actual
heating or cooling.
The holdback value is the amount, in degrees, by which the program setpoint can run
ahead of the measured temperature before holdback operates. The value applies to a
whole program.
To set the value press page twice, press scroll until 'Holdback Value' appears and
press up or down to set.
Holdback can be used in 'Rate', 'Time' and 'Step' segments.
• For 'Rate' and 'Time' segments holdback will operate during the segment.
• For a 'Step' segment holdback delays continuation to the next segment until the step
target is reached.
The 'Holdback Type' can be set as follows:
• Low Applies to heating only
• High Applies to cooling only
• Band Applies to both heating and cooling
• Off Holdback is switched off
To set the holdback type, press page twice, then press scroll until the display
shows 'Holdback Type' for each segment and press up or down to set.
The default setting for holdback is 'OFF'.
3.8.3 Wait Segments
Wait prevents the program proceeding to the next segment, in a similar way to
holdback, until the selected ‘Wait-For’ parameter has been met. There are 5 ‘Wait For’
parameters. The first 4 only work if there are configured inputs to the controller.
1. PrgIn1 Wait until Input 1 is true
2. PrgIn2 Wait until Input 2 is true
3. PrgIn 1&2 Wait until Inputs 1 AND 2 are true
4. PrgIn 1or2 Wait until Inputs 1 OR 2 is true
5. PVWaitIP Wait until the measured temperature reaches a threshold value before
continuing. It can operate in one of 4 ways:
1. 'Abs Hi' Wait until the measured temperature is greater than or equal to a
value 'WaitVal' set for that segment.
2. 'Abs Lo' Wait until the measured temperature is less than or equal to a value
'WaitVal' set for that segment.
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