Single Speed Series Fan Sequence; Modulating Speed Series Fan Sequence; Damper And Airflow Setpoint Control; Airflow Setpoints - Delta eZV-440 Application Manual

Single Speed Series Fan Sequence

A VAV series fan will run or start in the following cases:
When the fan is set to run constantly as determined by its
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To prevent the fan from "freewheeling" and running backwards, the series fan will run when
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differential air pressure is above 3.75Pa in the duct. The fan does not run when the duct
pressure drops below 2Pa for longer than 10 seconds.
The fan runs when there is a heating demand.
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The fan stops when:
There is no duct heating call.
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During those occupancy modes where the fan is not set to run constantly or set to run
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intermittently.
For example, if the fan is set to run constantly in Occupied and Unoccupied Override modes,
then during Unoccupied and Standby modes the fan does not run and only runs when there
is a heating demand.
Duct pressure drops below 2Pa for longer than 10 seconds.
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Modulating Speed Series Fan Sequence

In Occupied mode, a modulating series fan stop/start output sequences are the same as the ones
for a single speed series fan.
To operate in a constant volume mode with a modulating fan, the FanMinSpeed and
FanMaxSpeed settings are set to the same value.
When enabling variable volume control, the fan needs to track the primary airflow damper to
ensure the fan is always delivering the same or more airflow than what is being delivered by the
primary air damper. Otherwise the difference in airflows will be blown out through the induction port
into the ceiling plenum.

Damper and Airflow Setpoint Control

This section applies to the VAV/VVT algorithm.
The damper controls maintain an airflow setpoint that resets based on space heating or cooling
demand.

Airflow Setpoints

The following setpoints described in this section are accessible on the Setpoints tab on the
configuration page:
HeatingMaximum = maximum heating airflow setpoint
eZV-440 Application Guide
Edition 2.6
ConstantFanModes setting.
Page 67 of 84