36v cart not running

[scottyb]

Originally Posted by sdc19982002

If you udgrade the controller you would also have to upgrade the solenoid to handle the higher amperage.

That is correct. The stock solenoid is not rated for the increased amperage. Anyplace in the system that you have a component not rated for the working amperage you will have resistance which results in heat which will result in component failure.

[BillieS]

Originally Posted by scottyb

That is correct. The stock solenoid is not rated for the increased amperage. Anyplace in the system that you have a component not rated for the working amperage you will have resistance which results in heat which will result in component failure.

Ok! I looked at your controllers and see why now. Your weak points would be the switch, solenoid and any connections in between there and the controller.

For the perfect system, the total sum of all voltage drops should be equal to the total of the power being supplied. Anything less is lost in heat due to restance of some sort. I understand the Resistance = Heat thing (E=IxR).

Thank for helping a newby out.

[JohnnieB]

Originally Posted by BillieS

Ok! I looked at your controllers and see why now. Your weak points would be the switch, solenoid and any connections in between there and the controller.

For the perfect system, the total sum of all voltage drops should be equal to the total of the power being supplied. Anything less is lost in heat due to restance of some sort. I understand the Resistance = Heat thing (E=IxR).

Thank for helping a newby out.

In a perfect system, the only voltage drops would be across the Stator and Armature windings in the motor, and the MOSFETs in the controller if not at wide open throttle.

However, there are no perfect systems since batteries have internal resistance and the copper conductors in the high current cables intrinsically have resistance. 25' of perfectly construed 6Ga high current cables in perfect condition loses about 99W per 100A of current flow, 4Ga about 62W and 2Ga about 39W.

If any cable, connection or component is getting too warm to hold onto, it has too much resistance in it and should be repaired or replaced.

[BillieS]

Originally Posted by JohnnieB

In a perfect system, the only voltage drops would be across the Stator and Armature windings in the motor, and the MOSFETs in the controller if not at wide open throttle.

However, there are no perfect systems since batteries have internal resistance and the copper conductors in the high current cables intrinsically have resistance. 25' of perfectly construed 6Ga high current cables in perfect condition loses about 99W per 100A of current flow, 4Ga about 62W and 2Ga about 39W.

If any cable, connection or component is getting too warm to hold onto, it has too much resistance in it and should be repaired or replaced.

Yep, no perfect systems. Thanks!

[yurtle]

Originally Posted by BillieS

I understand the Resistance = Heat thing (E=IxR).

Thank for helping a newby out.

Heat = I^2R, so if you have a lot of amps going through even a relatively small resistance, it heats up a LOT.

[BillieS]

Originally Posted by yurtle

Heat = I^2R, so if you have a lot of amps going through even a relatively small resistance, it heats up a LOT.

Yep, enough to glow if you like. Similar to the old carts that use wire reostats.

[BillieS]

Originally Posted by JohnnieB

In a perfect system, the only voltage drops would be across the Stator and Armature windings in the motor, and the MOSFETs in the controller if not at wide open throttle.

However, there are no perfect systems since batteries have internal resistance and the copper conductors in the high current cables intrinsically have resistance. 25' of perfectly construed 6Ga high current cables in perfect condition loses about 99W per 100A of current flow, 4Ga about 62W and 2Ga about 39W.

If any cable, connection or component is getting too warm to hold onto, it has too much resistance in it and should be repaired or replaced.

I see you are from WV? What part? I am in the eastern panhandle, Martinsburg area.

[BillieS]

Originally Posted by scottyb

That is correct. The stock solenoid is not rated for the increased amperage. Anyplace in the system that you have a component not rated for the working amperage you will have resistance which results in heat which will result in component failure.

Thanks for your input. At first I could not figure out why I had to have a newer solenoid. But knowing that the controller was pulling more amps made sense. I also need to look at the F/R selector bolts. They are getting hot. you can see the discoloration in them. It may be because they are loose. Don't know. I will have to take the time to dig into it this weekend.

[scottyb]

Originally Posted by BillieS

Thanks for your input. At first I could not figure out why I had to have a newer solenoid. But knowing that the controller was pulling more amps made sense. I also need to look at the F/R selector bolts. They are getting hot. you can see the discoloration in them. It may be because they are loose. Don't know. I will have to take the time to dig into it this weekend.

I'll post a couple pics here. What you see ( if you look closely) is a discolored stud. In reality the stud has gotten hot enough to melt the Bakelite housing. This shows only inside the switch where the contact pressure and alignment has been compromised. Pics in a minute

[BillieS]

Yep, that is about what they look like. Just not enough to melt the housing yet.