Unoccupied mode - Verasys - Field Device - ZEC510

Verasys ZEC510 VAV Controllers Installation Guide

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  • When the zone temperature is between the unoccupied heating and cooling setpoints inside of the bias, the primary air damper is at the minimum cfm, and no mechanical heating runs.
  • When the zone temperature rises above the unoccupied cooling setpoint, the primary air damper increases the cfm, and no mechanical heating runs.
  • When the zone temperature falls below the unoccupied heating setpoint, the supplemental heating coil is fully used before the reheat heat coil engages. The damper is at the minimum cfm.

Unit enable

A network unit Enable signal controls the mode of the box. If you set the signal to Disable, all outputs for that box are disabled.

Fan control (optional)

A parallel fan cycles on when a request for heating occurs. The fan remains off in all other cases. Series fans run continuously in occupied mode. The fan moves from unoccupied mode to cycle on mode when it receives a request for heating or cooling.

Occupancy lighting switch (optional)

  • You can add an occupancy lighting switch to the box to temporarily set the VAV box to standby when mode it does not detect occupancy. When the box detects occupancy, the zone switches back to occupied mode.
  • Standby mode uses standby heating and cooling setpoints that are slightly higher and lower than the occupied cooling and heating setpoints, respectively. The VAV box also uses unoccupied flow setpoints.

Demand control ventilation (optional)

  • You can proportionally reset the minimum damper flows based on an air quality setpoint when you wire the zone CO2 sensors to the boxes to detect the air quality in the zone.
  • The reset of the damper minimum flows do not exceed the maximum value that you set. The CO2 sensor with the highest value determines the reset when you wire more than one CO2 sensor to the boxes.