Does anyone here have experience with repairing electric forklifts? We have one in the shop giving us fits and need some advice. Thanks.
I've done some work on electric forklifts, not an expert on one though. What trouble are you having? What machine? Does it have a system that gives you a trouble code?
It's an older 5000# Baker lift, also says Linde on it places. No electronics, other than the card in the EV-1 controller. Problem is - no forward. Checked fuses, changed card and direction selector switches on the steering column - no luck so far. When forward is selected, the contactor closes, but the motor doesn't run. Reverse works fine though. Any advice would be helpful!
Well, stuff like this is very difficult to troubleshoot without being there looking at it. Can't say for certain, but if it drives in reverse,doesn't sound like a problem with the drive motor or the EV1 motor controller. You said the fwd/rev contactor operates when you select either direction with direction contoller on steering column, but did you actually verify that the fwd contactor doesn't have a burnt contact? Another thing those type trucks do; when you select rev, it will engage the rev contactor, then when you step on the "throttle pedal" (I know...it's electric:tong), many machines power up a line contactor. Does your's do this? If so, does the line contactor power up when fwd is selected and you step on pedal. For certain, check all your wiring and all the connections of straps/cables at the control panel. I have seen bad connections of a strap or cable where they terminate on a component, and to look at it, it looks fine. Take the bolt out that secures it to the component, and you can see the evidence of arcing from a bad connection. I really don't think it's the drive motor. I'm not real familiar with the GE EV1 controller, but if it's anything like a Sevcon MOS 90 motor controller, if the motor had a problem, the EV1 wouldn't even let it drive in reverse. And I don't think it's the EV1 being the problem, unless it receives an input from the fwd/rev selector on steering column and you have a problem with input from fwd direction of selector. I just don't know enough about your particular machines components to give more specific advice. Let us know if you find the cause of the problem.
We had one of those old white Bakers once apon a time. Most common cause would be burnt/pitted contactors. Sounds like you know which set "clicks" when you put it into forward. Get after that set with a small, smooth file and dress them up a bit. Most times that's all they need. Are the connections on your drive motor easy to get at? Are you showing power from the + to - in both directions?
Thanks for the good ideas. Sorry it's been some time, but we've had some stuff going on in the shop. Today I think I've got it fixed, so, I'd like to follow up. After taking the contactors apart several times and just observing how they operated, I realized that the pads that make contact and transmit the current where worn out of spec. So I got some silver solder like the HVAC boys use to solder the A/C lines and built the pads up, ground them flat, and re-assembled. Works!!!! Thanks again for the direction guys.
no forward problem Check the f& R contactors make sure the tips are making good contact