SYX66x Commissioning Guide
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Page 24 of 61
6.
Controller Principles and Operational Features in detail
6.1
Optimum Start
The optimum start facility is a self-learning routine which will search for the latest time to start in order to achieve the
desired
Space Set point
at the start of occupation. The performance of the optimiser is continually monitored
throughout the pre-heat period and updated to ensure an accurate response in all conditions. Four programmable
occupation periods for each day of the week are available. Each of the four daily periods will be individually optimised
on and off as required.
The optimum start preheat time is limited to a minimum rate 0.5 hours C/Hr. This limit will at optimum start the boiler(s)
and heating pump are switched on and the controller enters a boost mode. If two boilers are being used they are
fired at a 10 second interval. If used as an optimiser only then during boost the flow temperature will be limited to
the boiler(s) thermostat setting or the
Boiler Flow Set point
value, whichever is lowest.
If used as an optimiser/compensator controller, the flow temperature will be limited to the
Compensated Flow High
value. The boost mode will continue until the required space temperature is achieved.
The self-learning process of the optimiser will be inhibited if the controller is in an alarm mode. It is essential that the
Space Set point
temperature can be achieved to allow compensation to begin and prevent the self-learning optimum
start routine progressively advancing the start time. The adaption can be stopped using the Set-Up menu, this should
be used when adaption alarm issues are persistent due to rectification works not within project or time scope.
If the heating room set point is not achieved then the adapted limit will be reached in approximately 14 days
operation. If this limit is evident (alarm activated) please investigate the following:
1
The room sensor is located in a space where adequate heat source is available
2
The heat source (Fan Heater, Radiator) is operating when required
3
The heat source is effective (blocked filters, air locked, covered over)
4
The heat source is not being controlled by another control device (thermostat)
5
The thermostat must be set to operate above the SYX66x optimiser set point
6
The boost heated flow temperature is being achieved at the location of the heat emitter and is being
enabled by the optimiser for the zone in question.
7
The time of the controller is correct
8
The time schedule is correct
9
The maximum flow temperature set point is at the correct value for the system
10 The heat source (boilers) thermostats are set above the SYX66x maximum flow set point
6.2
Optimum Stop
Optimum stop is a self-learning routine that predicts how long before the end of the occupation period the heating
can be switched off, whilst ensuring that the space temperature does not drop more than one degree below
Space
Set point
before the end of occupation. When heating is switched off by optimum stop, pump run-on will commence.
If the space temperature drops more than 1 degree below the day set point then heating will switch back on and the
controller will learn from this. Optimum Stop can be disabled in the Heating
Menu “Set-up” options should this feature
not be required.
6.3
Outside High Shutdown
The Outside High feature will disable the heating if the Outside Air Temperature goes above this Set point. The
Outside Air Temperature will need be two degrees below the
Outside High Set point
before the heating will be re-
enabled. If this feature is not required then the
Outside High Set point
should be set to a high value.
