Can I use a 10:1 or 20:1 attenuator in place of the X100 differential probe to measure mains voltage as long as I keep my laptop and scope isolated from any contact with building ground or mains power? Using a 4425 or 3423 automotive scope.

Thanks. I never thought about using RMS setting in pico. I have attached a circuit diagram and photos of the mfg diagrams for the pump protection module and capacitor / starter boxes. I think I will replace the run capacitor and see if helps. I will also post it in the T&M forum. I'm really curious ...

I am using a 3423 automotive scope and pico 6 automotive

I couldn't think of where else to post it. I was hoping someone that understood 3 phase electric vehicles motors would be able to explain this. Do you know of another forum that might help?

I have been unable to find anything online to help me understand what is going on in this waveform. I am hoping somebody on this site should be able to figure it out. This is a 220 volt AC, capacitor start ,single phase deep well pump. It has 2 line voltage wires and one ground wire. I am using pico...

Great question. Yes they were both at about 750 rpm. I should have mentioned that in the original post. From now on when I post something I will make sure all the screen shots are zoomed in the same to make comparison easier.

Thanks, I don't mind at all. That was my first time posting to this board. I thought I had atached the screen shots, but I must have done something wrong.

This car was sent to me from another shop because they were too busy to get to it, and the lady needed it repaired ASAP. Symptoms were engine oil warning lamp would flicker when engine was first started cold. After warming up the oil lamp stayed on and the engine had a loud rattling noise. The first...