Monarch 10ee frequency drive or motor problem

I bought a 1957 Monarch 10ee that was converted to a frequency drive and 3 phase motor system. The motor is by EBC (Equipment Builders Co.) and is 2hp. It has a 145TC frame and mounts directly to the backgear gearbox. The Cat number is EB002-4FKA. It is made in China and I could not find to much information about it. It does not have anything on the motor plate that says it is inverter ready. The motor looks ok, but I would guess it probably is cheap. The frequency drive is a Hitachi SJ200. It is for a 1.5/(2) hp motor. Single phase 220 a/c in with 3 phase output. The lathe has worked perfectly for the last 2 years until recently. The problem first started when I would turn the lathe off and it would not restart. A F004 would show on the drive. I would just hit reset on the drive and it would run again. This has been going on for 6 months. Now, when I try to start the lathe it starts to go and then studders and stops. a E02 error shows. I can get it to run if I start with backgear engaged. It still studders a little bit on initial start, but runs. The E02 says to check the spindle is free. I took the motor and backgear out of the lathe and I spun the pulley with both backgear engaged and disengaged. Smooth as silk. I then turned the spindle by hand and it was also smooth. It also says to check for shorts, but no wires seem to be loose. But then I discovered something very interesting. I started lathe with backgear engaged and it ran. I then touched the speed control and I got a mild electrical shock. The lathe actually rests on 4 X 4 wood posts and when I touched the speed control I was barefooted on concrete. I put my tennis shoes on and touched it again and no shock. So somewhere electricity is leaking and wants to go to ground. I am looking for advice on what to do. Should I buy a better USA motor and try again? Should I buy a new frequency drive and try it on the Chinese motor? Maybe I should buy both. Any suggestions on troubleshooting would sure be appreciated by this hobby machinist.

First do a leakage check on the motor by disconnecting it from everything else and checking from the leads to the frame. An ohmeter may show something. If it does, the motor needs to be rewound or replaced. The voltage an ohmeter applies is not enough to show all leakage, so if it does not, find someone who has a megger or one of the breakdown testers designed specifically for motors. A motor shop should have one. If the motor is all right, the drive is probably scrap. Unless you have sufficient knowledge to do it yourself, it is probably not economically repairable. A 2 hp motor is too small for that lathe, anyway. It originally had a 3 hp motor and the later DC lathes had 5 hp. The AC drives have 7 1/2.

Bill

Thanks For the help Bill. I ended up finding a new Hitachi WJ200 and a new Baldor Inverter duty motor on ebay and am putting it back together. I had to go with the 2hp motor because everything was built to hook up to the backgear with a 145tc frame and I did not want to rebuild everything. I know everybody says that it would be underpowered, but it really worked great for me. I never stall it. If I am threading or using low rpm I just use the backgear.