Fluid Coupling Driven by SS


Thread Starter

Bill Code

We have a dilemma. In order to maintain a schedule, our project group is considering driving a number of existing fluid couplings in conveyor drive applications with electric soft starters. Ultimately, the fluid couplings will be replaced with rigid couplings and the electric soft starters will provide the soft start function currently provided by the couplings (the decision to replace the fluid couplings is "fait accompli").

So in the meantime, is it practical to drive the fluid coupling with the electric soft start set to accelerate the drive motor over a steep ramp? We see risk of overheating the oil in the fluid coupling if accelerated over a "long" time, but we can't see any problems with the steep ramp. The motor is 75 HP, 460 V and the electric soft start is rated for 250 A. Our thinking is that the electric soft start is able to source sufficient current for a steep ramp and the fluid coupling would then be performing "normally".

Does anyone have any experience and lessons learned from driving a fluid coupling with an electric soft start?

Thanks for your time,