User Manual

Sequence of Operation
Wiring Diagram
16
Siemens Industry, Inc.
Application Note, App 14900
140-1231
2020-02-11
ON Mode – The fan relay is energized regardless of whether or not there is a call for
heating or cooling, unless the unit is set to Unit Off.
Fan Opr - The fan relay can be set to be energized or not energized upon call for heat
using Paramater P105 (HTG FAN). If P105 is set to ELE, the fan relay responds to the
call for heat to energize. If P105 is set to gAS, the fan relay will not be energized upon
a call for heat; instead the blower motor is energized by the furnace control board. The
furnace control board provides fan delay on/off, protection, and provides other control
functions as it directly interacts with the ignition/blower sequence.
Wiring Diagram
CAUTION
The thermostat’s digital outputs only control 24 Vac loads. The maximum rating is 1A
(24 VA) for each DO. Total maximum rating for the thermostat, including all energized
DOs is 4A (96 VA). Auxiliary Output 3 (OUT3) may be configured as a Dry Contact by
removing jumper RC-C3 and connecting the controlled device to both terminals OUT3
and C3.
An external interposing relay is required for any of the following:
- VA requirements higher than the maximum
- 110 or 220 Vac requirements
- DC power requirements
Configurable Inputs are Off (default). See RDY2000BN BACnet Enabled Commercial
Room Thermostat Installation Instructions (125-1009), 300 Series Parameters to
enable inputs. Temperature sensors that may be configured as Thermistor inputs are:
10K Type 2 (default) or 0 to 10V inputs. Humidity and CO2 sensors may be
configured as 0 to 10V inputs. Occupancy and Fault sensors may be configured as
digital inputs.