American Standard UV05 Exhaust Fan ON/OFF Signal, Auxiliary Heat Signal, Start/Stop Calculation

Description of Operation

Exhaust Fan ON/OFF Signal

This relay output provides one set of Normally Open dry contacts that can be used to signal the operation of an exhaust fan. When the OA damper opens more than the Energize Exhaust Fan OA Damper set point, then the relay output signals the exhaust fan ON (contacts closed). When the OA damper closes below this set point, the relay output signals the exhaust fan OFF (contacts open).

Auxiliary Heat Signal

This relay output provides one set of Normally Open dry contacts that can be used to operate an auxiliary heat device. The UVC by default is configured to operate a Normally Open auxiliary heat device (de-energize when heat is required), such as a wet heat valve actuator with a spring setup to open upon power failure. However, the Auxiliary Heat Configuration variable can be used to set the UVC to use a Normally Closed auxiliary heat device (energize when heat is required), such as electric heat.

Table 20: Auxiliary heat start/stop calculation

Start/Stop	Calculation
Auxiliary heat	Primary Heat PI-Loop = saturated high (100%) for
starts when:	more than two minutes
	AND
	EffectiveSpaceTemp ≤ EffectiveSetpoint –
	AuxiliaryHeatStartDifferential
Auxiliary heat	EffectiveSpaceTemp ≥ (EffectiveSetpoint –
stops when:	AuxiliaryHeatStartDifferential) +
	AuxiliaryHeatStopDifferential

McQuay OM 751 39