Three phase rotation meter

If functional - sounds like someone is junking out a company - and all electricians would have one.
Useful on stuff that can't run backwards and is on 3 phase.
e.g. can making or automated machines.
Martin

I have a device that hooks up to a motor and determines which way to wire it correctly.
i

They are new, electronic rotation meters. They are cheap enough for guys converting old machines to have one in their toolbox.

I had a student who was a journey man with his Dad - a Master Electrician. The student was working in a can company and they just got a new machine in. It was a 'twisted' three phase and would physically harm itself if phasing of the AC was wrong.
This was 40 years ago and I was able to find a unit for him. His Dad's company didn't have one nor knew where to find one.
Twisted - there were phasing windings - two each attached to each leg of the three phase. (Star or Wye formation.).
When drawing them one puts in the phasing of each based from the previous winding. Twisted fits.
Martin