Drill Press Aggravation?

[randyjaco]

I have a Clausing drill press with a 2 speed 3 phase motor. On the press is a 2 speed drum switch. Everything works well on the drill press, but I have a constant problem with it tripping the TECO phase converter and giving me an “OC-C” error. This only occurs when I use low speed, never on high speed. It will run in low speed but often when I switch to OFF I will get the error. The phase converter is remoted, so it is becoming a PIA. I have to go to the phase converter, turn the phase converter completely off to reset it or I have to turn the remote on/off switch to the Off position and return to the P/C and push reset to reset the phase converter.

I presume that it is something in the drum switch, because it happens less often when I switch to OFF very quickly. The slower I switch to OFF the more it trips the phase converter.
Any suggestions as to how I can fix the problem?
TIA
Randy

 

[Tony Wells]

Multi-pole switches won't make/break all poles at exactly the same time, and they may give the VFD some grief. You might tweak it using a meter and working the switch to see if one set of contacts is slow. Two meters would be better, 3 best if it is a 3 pole switch. Probably could do a little bending of the contact arms.

Just a thought.

 

[randyjaco]

Actually I fixed the problem by securing a part of the switch with a wedge (a straight pin). There was a slight movement between 2 of the plastic components. But with the warnings from this site and others, I will change the wall plug to RPC power. Darn, I sure liked being able to fine tune the speed.

Thanks for the responses ::thumbzup::

Randy

 

[randyjaco]

Basically it was not to put any switching between the VFD and the motor or run the risk of burning up the VFD. I understand that an RPC is better capable of handing the impulses and irregularities of the 3 phase drum switch. Or at least that is how I understand it. ::

Randy

 

[Tony Wells]

I must be missing something too. The VFD will take the place of the drum switch, in effect. Single phase in, and 3 phase, forward and reverse out. Plus variable speed.

Randy, you lost me, unless you are needing fast F/R switching like in driving a tap or something. Not sure how that would work with a VFD.

 

[Tony Wells]

Ed, that was about the only thing I could think of where a guy might want to go forward and reverse pretty quickly, and perhaps repeatedly to break the chip, say,....in a blind hole.

 

[Tony Wells]

This is one argument in favor of a tapping head that auto-reverses. I generally don't power tap blind holes, but if there are enough of them, I'll set up the tapping head and do it. Even on thru-holes, I do the F/R/F thing unless I have a spiral point gun tap.