Winding Diagram for 3 phase 2 Speed Induction Motor

Have you spoken to the crane manufacturer, Mildred? If not, why not? Did you source a replacement motor? If not, why not? What do your collapse indemnity insurers have to say about this crane? If the motor is shot then the rest of it might be beyond salvage too.

Scrapping it is a solution. Hoping for some sense from your side.

Given that the motor is for crane duty I'm going to back Officer Crabtree. Source an OEM motor or get it repaired by a reputable rewind house.

Crane motors are subject to regular overloads and arduous duty. I don't know where you're based but in the UK there's only a couple of rewind houses I'd trust to do the work even though it involves paying premium prices.

René Artois

Sounds like you have a bad OL or contact in your low speed motor controller. Be sure to check each fuse.

1, Make sure your Over Loads are completely reset. You can push the reset button but a bad OL will not reset. Turn power off and conduct a DC resistance check on each OL thermal heater.

3, With the power off, check each fuse with a DC Ohm meter and again with the power on with each phase, voltage to ground.

2. Check the controller contacts. Remove and mark the low speed motor leads. Force the low speed controller ON (usually by hand) and check each phase voltage to ground at both the controller and the motor if necessary.

This will eliminate a controller or power related problems. Good Luck.

Have you ever actually worked on a crane?

Both AC and DC. Why?

1. Hi I have just rewound a larger 2 speed motor from a stahl crane motor made by Siemens do you still need help with yours?

If he hasn’t figured it out in 7 years, it’s probably no longer important.