User Manual

Sequence of Operation
Auxiliary Sequences
17
Siemens Industry, Inc.
Application Note, App 14900
140-1231
2020-02-11
Figure 3: Wiring Schematic, Conventional.
Auxiliary Sequences
The RDY2000BN primary sequences are designed to control single and multi-stage
heating/cooling systems to maintain a user-defined temperature setpoint.
The following auxiliary sequences are available to optimize occupant comfort and
system efficiency:
Humidification
If one of the configurable digital outputs is configured for a humidification function, the
corresponding relay will close and enable a 24 Vac output signal to be transmitted to
the humidification device. Humidification and dehumidification relays, if configured as
such, cannot be energized simultaneously.
● The humidification relay (monitored through HmdyOn) will be energized when
measured humidity drops approximately 4% below setpoint (HmdySp) and will be
de-energized when measured humidity reaches setpoint. Deadbands and proof
timers are in force to prevent short cycling. The thermostat controls humidification
only in Heating mode.
● You must enter a humidity setpoint (HmdySp). The valid range is 10 to 90%; the
default value is 25%. If the humidity drops to 4% below setpoint, a 30-second proof
timer engages. If the humidity is still 4% below the setpoint after the proof timer
times out, the humidification relay energizes.