Fail-safe actuators
Actuators that move the damper to a safe position by themselves on power failure – typically closing the outdoor air intake so the coil does not freeze. The energy for the return is stored in a spring or a SuperCap capacitor.
Actuator series
TF and LF
2.5 and 4 Nm with spring return for small dampers.
NF and SF
10 and 20 Nm with spring return – the most common choice for air handling unit dampers. NFA and SFA versions with AC 100…240 V supply.
EF
30 Nm with spring return for larger dampers.
GK
40 Nm with SuperCap fail-safe and a selectable fail-safe position.
Suffixes
-S2 two auxiliary switches, SR modulating 2…10 V, MP MP-Bus, MOD BACnet / Modbus.
Product sorting
List of products
What to look for when choosing
Spring or SuperCap
A spring is purely mechanical; SuperCap lets you set any fail-safe position.
Damper size
Choose by damper area – just as for non-fail-safe actuators.
Return to position
The spring returns the damper in about 20 s; motor running time is 40 to 150 s.
Direction of rotation
The fail-safe direction is set by turning the actuator over on the shaft (L / R).