Distech Controls ECLYPSE ECY-303 - Damper Control Strategy

49ECY-303 Preloaded Applications
If the variable EnableDehumid (BV14) is set to Enable, meaning that the cooling coil is positionned be-
fore the heating coil in the unit, the system can dehumidify the space. Based on DehumidifySP(AV54),
the 1
st
cooling stage can be enabled to dehumidify the space.
Damper Controls
The dampers are controlled based on the DampersConfig (MSV35) variable. This variable can be
used to configure 0-10V, 2-10V dampers with or without Power Exhaust. The dampers can also be
configured to be only a digital economizer enable signal or a min position enable signal.
When the dampers are configured for 0-10V or 2-10V, the dampers are set to MinDamperPos (AV32)
in standby and occupied mode. When there is a call for cooling and the outdoor temperature is suit-
able for cooling the space, the dampers will be used as a first stage of cooling. The dampers will be
controlled to maintain the DampersDischAirSP(AV30). If the system is equipped with outdoor, return
humidity and temperature sensors, the enthalpy of both the return and outside air will be calculated.
The dampers will be enabled when the outdoor enthalpy is lower than the indoor enthalpy.
When the system is equipped with a Space or Return CO
2
sensor, the dampers will be set to Min-
DamperCO2 (AV33) in standby and occupied mode. The CO
2
control loop will modulate the dampers
between MinDamperCO2 (AV33) and MinDamperPos (AV32).
The power exhaust will be enabled based on the dampers position. When the dampers position is
greather than ExhaustStartSP (AV83), the power exhaust is started. When the dampers position is
lowe than ExhaustStopSP (AV84), the power exhaust is stopped.
When the dampers are configured for EconEnable, the output will be enabled as a 1
st
stage of cooling
on a call for cooling when the outdoor temperature is suitable for cooling the space. If the system is
equipped with outdoor, return humidity and temperature sensors, the enthalpy of both the return and
outside air will be calculated. The economizer will be enabled when the outdoor enthalpy is lower than
the indoor enthalpy.
Sequence of Operation