bradpotts00 (Customer) asked a question.
I'm trying to control a motor with a brake that raises and lowers a rack into a dip tank. When the drive gets its lowering command simultaneously with the brake releasing, the rack will initially drop too quickly.
I attempted to use the crane function to delay the release of the brake, but it seems I don't know how the function works. I set P02.13 to 42 and hook up my brake relay to the NO relay contacts. Then I set P02.34 and P02.58 to low frequency settings that I thought would bracket the frequency at which the relay contacts would close and release the brake. However, the contacts never closed, and the brake never released.
What am I missing?
Do I need to set it up for vector control for this to work?
Thanks in advance.
Brad
You're right, P02.34 and P02.58 adjusts frequency for brake output. P02.34 is output turn-on freq. for starting (increasing freq.), P02.58 is output turn-off freq. for stopping (decreasing freq.). (P02.58 must be lower than P02.34) Also dwell times (P07.15, P0.17) and dwell freq. (P0.16, P0.18) should be adjusted. (P07.16=P02.34, P07.18=P02.58).
Is this a new installation? Or has this been working and you're replacing the drive on an existing working system. If an existing working system, has the problem been getting worse over time? Or did the problem appear with the new VFD? I am wondering if the problem is due to a mechanical problem, rather than a V/Hz/vector control problem. Do you have (2) brakes, one for holding the load at position, and one for holding back the load from running away? Or do you have mechanical gear reduction or worm drive that holds back the load from running away? (I'm guessing not because you do have run-away) Or does your brake have adjustments, so that when set, the brake holds the load at position, and when released, the brake holds back the load from running away? Do you get any OV or OC on the VFD?