Night Setback

Some customers, especially commercial customers, will want to use a night thermostat to set back all the zones in a zoning system to allow for occupied and unoccupied temperature scheduling of the building.

The components needed are a night thermostat, a 7-day time clock, and an override timer. Occupied and unoccupied scheduling can be accomplished with most zoning systems by interrupting the “R wire” between the zone control panel and the equipment. Other zoning system control boards like a Jackson Systems’ Z-2000 have terminals built into the boards for these connections. The time clock is set to open the equipment control circuit at night which will lower temperature in the case of heating (and raise the temperature in the case of cooling) to the set point on the night thermostat. The override timer is used to override the night thermostat and give control back to the zone control system.

As for wiring of the components, this depends on the control board used.  The time clock, night thermostat, and override timer must be in parallel.  Either the board must accomplish this, so you will see a separate terminal for each device, or you must physically wire the three devices in parallel.

Using these components will allow for even greater energy savings for the customer.

Updated: February 20, 2009 — 11:14 am

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