G19 solenoid problem

[toolman87]

I have a G19 cart that has been upgraded some. It has 48volts, 200 amp solenoid, and altrax DCX400 controller, 3.5 hp yamaha motor. It has burned up two contact solenoids. I took the solenoid apart and the load side contact is melted down but battery side is good and the coil is still pulling in. I am not sure what to check. Could I have a ground issue? Thanks Karl

[Dryseals]

Originally Posted by toolman87

I have a G19 cart that has been upgraded some. It has 48volts, 200 amp solenoid, and altrax DCX400 controller, 3.5 hp yamaha motor. It has burned up two contact solenoids. I took the solenoid apart and the load side contact is melted down but battery side is good and the coil is still pulling in. I am not sure what to check. Could I have a ground issue? Thanks Karl

It's normal for a contact to burn after years of use. But if it's burning up quickly then there are a few things to look at. Arcing is what burns them up, the constant opening and closing of the switch. With an induction motor, such as the carts, every time the power is taken of the motor, the flux field in the windings to collapse and return to the source. This shouldn't cause the contacts to burn unless the solenoid is dropping out too.
I'm going to take a WAG here and say your solenoid is dropping out when you take your foot off the accelerator. Put a meter on the solenoid and watch the voltage when you take your foot of the throttle. If it dips, there's your problem.
I've seen this in industrial applications many times, a large inductive field gets turned off and the reverse voltage from the flux field is enough to drop the voltage to other devices in the same circuit, just long enough to cause problems down the road.

[toolman87]

I ordered a new solenoid, It should be here this week. I will put the meter to it and see what I have. I know on the previous solenoid that when I put the pedal down I could hear it click and when I let up it clicked again. Is this normal operation of the solenoid? I bought this cart in this condition and I am worried that I may put a new solenoid on and have the same thing happen. There were no diode or resistor on the old solenoid but the new one comes with them. I hope that helps the arcing. Anything that I should check out besides the solenoid? Thanks Karl

[Dryseals]

Originally Posted by toolman87

I ordered a new solenoid, It should be here this week. I will put the meter to it and see what I have. I know on the previous solenoid that when I put the pedal down I could hear it click and when I let up it clicked again. Is this normal operation of the solenoid? I bought this cart in this condition and I am worried that I may put a new solenoid on and have the same thing happen. There were no diode or resistor on the old solenoid but the new one comes with them. I hope that helps the arcing. Anything that I should check out besides the solenoid? Thanks Karl

The solenoid cycles with the key switch and the foot pedal in series. A positive is applied through the key and to the controller. The solenoid shouldn't kick in until you press the throttle and after you release the throttle, it should be a few seconds before the solenoid kicks out. I'm still fairly new to the controls on these things, but I do industrial controls for a living so figuring out the hows and whys of the controller functions is nothing new.
This is all controlled by the switch on the throttle. Timing is important. If the controller tries to feed the motor at the same time the throttle is pressed, it'll arc. So there should be a slight delay from when you are sitting at a stand still and press the throttle. This allows the solenoid to kick in and then the controller begin to feed the motor. If you press the throttle and release it with out moving, then it should take a few seonds before the solenoid kicks back out. I haven't looked into the regen aspect, but I would believe the same function occurs during regen, the solenoid stays in until a certian speed is reached monitored by the tach.
Your controller is programable, my guess is that something is telling the solenoid to kick out when the power is flowing and it probably during regen mode, their braking. There's a note in the program manual about the needed speed for regen in the 48 volt models. Something tells me this is were you'll find your arc problem.

[toolman87]

Thanks, I will check the programing too.

[toolman87]

Well I installed the new 400amp solenoid with resister and diode. So far it is working OK. I looked at the program as well and not much there except that the brake is off and the cart does coast when letting off the accelerator. the speed is at 100, the brake current is at 75 and the out put current is at 100. The throttle profile is at custom. The cart seems a bit jittery when you just push the pedal in a little but I would guess that it must have a certain amount to start moving steady. I will update if anything new happens. Thanks Karl