1. TYPES OF SPEED CONTROLLERS
Stepwise:
Speed control via multiple switch, in steps
Single Phase - 7 Steps
Three Phase - 5 Steps
Stepless:
Speed control via rotary knob and scale 0...100 %.
in Casing:
Complete ready for wiring with integrated contactor, on/off keys,overload protection via thermal contacts in motor, secondarys fuses or in case of types FDR 20/3, FDR 40/3, FDR 200/3, FDR 400/3 instead of fuses one or two protective motor relays adjustable according to the nominal current of the motor or each stator of double motor. All contained in a ventilated sheet metal housing regardings three-phase A.C. whereas in compact plastic housing for single-phase current.
Without Casing:
Stepped Transformer or rotary stepless transformer for installation in clients casing. Protection class 00.
2. OPERATION AND FUNCTION
Operation of the fan is via the on/off key of the speed controller. The controller is interlinked with the thermal contacts in the fan motor. When operating the indicator light glows. Should the fan stop due to power failure, open thermal contacts etc. the indicator light will extinguish.
The stepped controller will not function in position "0". A speed must be selected to enable the contactor to function.
The stepless speed controller will function at any setting.
Ancillary items such as electro valves or damper motors can be switched via the terminals Neutral - T for stepped controllers or Neutral - 6 for stepless controller.
