Application

Room Segment Functions
Device Control Functions HVAC
65
Siemens Industry, Inc.
Application Note
A6V11692053
Smart Infrastructure – Building Products
2019-04-01
NOTE:
Signals in table are internal signals, not BACnet objects. For this reason they are
not visible in the tool, but the parameters associated with them are. See
Comments column for hints on parameters that affect interlock functionality.
Signal
Type
Description
Comment
AirFlSta
Boolean
Air flow status → Interlock signal, from a fan or a supply
damper, that keeps the coil locked unless that same fan or
supply damper provides airflow.
No related parameters in
electric coils. AirFlSta is hard-
coded.
AirFlHReq
Boolean
Air flow heating request → Initiates airflow (fan turns on or
VAV supply damper provides airflow) to satisfy airflow
support request for heating. Signal is sent to fan or VAV
supply damper depending on application.
See Configuration section for
parameters named
"...AirFlHReq".
AirFlHldH
Boolean
Air flow hold for heating → Interlock signal to fan or supply
damper requesting equipment protection airflow support for
a period of time, such as when the electric heating coil has
just turned off.
See Configuration section for
parameters named
"...AirFlHldH".
Equipment Safety - High Temperature Cut-out Switch
The electric heating coil control logic is configured for heating coil over-
temperature detection input (HclOvrTDet) from a high temperature cut-out
switch.
When the switch activates, the coil is commanded off at equipment protection
priority and a signal is sent to the source of airflow to hold / maintain airflow. A
timer prevents the source of airflow from stopping until after the timer expires.
NOTE:
This equipment safety is optional and NOT IMPLEMENTED in this application
template.
Monitor Electric Power Usage
The nominal electric power usage of the electric heating coil(s) is provided for
energy monitoring and coordination with other devices. When the coil is ON at
100%, the heating coil electric power (HclElPwr) is equal to the Nominal Electric
Power (NomElPwr) of the coil; when the heating coil is ON at 50% the heating coil
electric power (HclElPwr) is equal to the 50% of the Nominal Electric Power
[NomElPwr] of the coil.