Data Sheet for Product

6
Siemens
A6V12068497_en--_b
Smart Infrastructure
2021-12-15
Advanced functions
RDF270 fresh air unit controller provides different functions for equipment from basic with
manual 3-speed fan to advanced with ECM fan, internal / external circulation and bypass
function.
Internal / External air circulation
Some fresh air units only have a single duct and can be set to introduce fresh air from out-
side or circulate air via a built-in filter to maintain good air quality.
Dual duct fresh air units enable both internal and external air circulation.
Bypass function
This function is available in a dual duct fresh air unit and for external circulation only.
Without bypass function, outside air is preheated or precooled by extract air via the built-in
heat exchanger in the fresh air unit. As a result, the outside air temperature is maintained
prior to entering the indoor area. Little time is required to heat up or cool down outside air us-
ing heating or cooling units because the temperature deviation is little, thus saving energy.
Other situations require a bypass function.
If, e.g. the indoor area is too hot or too cold and the outside temperature is cooler or warmer,
simply introducing the outside temperature to maintain comfort via bypass (or no heat ex-
change with extract air) is extremely useful and economic.
FAU-ECO function: (Eco-balance)
FAU-ECO is an automatic function to switch between internal and external air circulation,
thus requiring that P25 is enabled or P25 = 1. In addition, to enable this function P02 must
also be set to 2, then select Eco Mode via the power button.
When FAU-ECO is selected, the RDF270 changes over air circulation between external and
internal as per the time ratio defined in parameter P26. E.g., the factory setting (P26 = 1:5)
means that within one hour, RDF270 stays in external air circulation for 10 minutes, then
switches to internal circulation for 50 minutes. The setting repeats while FAU-ECO mode is
active.
This function can help users to maintain a balanced eco system by controlling the amount of
fresh air inside buildings or apartments required to achieve good air quality for the living
space.
For related applications, see Application setup based on selection of fresh air unit [▶ 15].
Error handling
TOUCH IC error
“Er2” is displayed upon internal TOUCH IC error.
Control parameters
Parameter settings
To optimize control performance, use the local HMI to enter parameter mode and adjust a
number of control parameters. All control parameter settings are retained after power failure.