Document No. 129-905
Installation Instructions
March 26, 2015
Siemens Industry, Inc.
Page 15
of 18
Dehumidification
Parameters
•
P317/ P318/P319: One of these must be set to 2
•
P320: NO (default) = Dehumidification will only
occur if there is a call for cooling. YES =
Dehumidification relay will be energized
independently of heating and cooling relays.
•
Dehumidity Setpoint: User adjustable to desired
level in dehumidification mode.
Sensors: Onboard humidity sensor or optional remote
humidity sensor.
The dehumidification relay will energize when measured
humidity rises approximately 4% above setpoint and will
de-energize when measured humidity reaches setpoint.
Deadbands and proof timers are in force to prevent short
cycling
Economizer Enable
Parameters
•
P317/P318/P319: One of these must be set to 5.
•
P301/P305/P309/P313: One of these must be
set to 8 if the optional occupancy sensor is used.
Sensors: None required, however an optional occupancy
sensor can be used instead of, or in conjunction with the
scheduler to determine occupancy.
The Economizer Enable relay will be energized
whenever a cooling relay is energized or the space is
occupied. The thermostat will use the scheduled
setpoints to predict when space is occupied. An optional
occupancy sensor can also be used for definitive proof
of occupancy.
An output configured for Occupancy Notification can also
be used for Economizer Enable.
Pre-Purge
Parameters
•
P317/P318/P319: One of these must be set to 5.
•
P403
Sensors: None required.
To enable the economizer and energize the fan relay
prior to scheduled occupancy, set P403 to the number of
hours before scheduled occupancy for pre-purge to
begin. This function requires a schedule to be
configured.
Occupancy Notification
Parameters
•
P301/P305/P309/P313: If the optional occupancy
sensor is used, one of these must be set to 8.
•
P317/P318/P319: To signal an external device that
the space is occupied, one of these must be set to 3
•
P404: If the optional occupancy sensor is used,
P404 can be used to set a minimum run timer for
any actions that are activated by occupancy, such
as Economizer Enable, control to occupied
temperature setpoints, and so on. Note that many
occupancy sensors also have onboard proof timers.
There are two primary methods by which the thermostat
can assume the space is occupied.
1. In Cooling mode, it will assume that scheduled
periods with lower setpoint(s) indicate
occupancy. In Heating mode, it will assume
occupancy during periods of higher setpoints.
2. During periods in which the schedule indicates
the space is unoccupied, any human interaction
with the thermostat (for example, setpoint
adjustment) will put the thermostat into
Occupied mode.
The optional occupancy sensor can be used in
conjunction with the schedule. The thermostat will follow
the assumptions above, but an input from the occupancy
sensor during a scheduled unoccupied period will put the
thermostat in the Occupied mode for the duration of the
timer set in P404.
To utilize the Occupancy functions, the thermostat must
have an active schedule.
Air Quality Management
Parameters
•
P301/P305/P309/P313: One of these must be
set to 7.
•
P317/P318/P319: One of these must be set to 4.
•
P402: CO2 Setpoint
Sensors: Optional CO2 Sensor
•
If measured CO2 exceeds setpoint by 200 PPM,
the Air Quality output and fan relays will be
energized
.
The minimum run time is 5 minutes.
•
When measured CO2 falls below setpoint and
appropriate minimum run time has been met, the
Air Quality output relay will be de-energized and
the fan relay shall revert to normal operation.
