M- wire getting very hot to the touch at the controller

[cableguy_hd]

Never really noticed this until last night... Took my kids for a ride @ the neighborhood on asphalt and did a touch test afterwards. Batteries were fine but solenoid and M- were very hot @ the controller. I did climb some hills tho. Probably 30-45 min. worth of riding... Should I be worried?

4g wire 48v series TXT 5" lifted 22's 10" rims back seat windshield down.... hope I covered all the particulars asked for

[Knothead]

What size controller/solenoid have you got? Are the connections clean & tight at the hot locations?

[JohnnieB]

Since you are running 48V, 4Ga cables should suffice and because you are running 48V, you most likely have a 400A or 500A controller and at least a 200A solenoid.

Like Knothead said, dirty/loose connections would be the first thing to check for.

Another possibility is the stacking order of the cable/wire connections on the terminals.

The cables carrying the most amps should be in the most intimate contact with the solenoid terminal. The high current cables go on the studs first, than a flat washer, then the resistor, another flat washer, a lock washer and the nut.

The M- terminal is tinned copper and unlike the battery terminals (lead) it doesn't flow around irregularities in the cable lug, so any bumps on the cable lug will raise other portions of it off the surface causing a poor connection. Rub the side on the cable lug that goes against the M- terminal on a flat file until the entire surface is flat and shiny.

Bottom line: With the big tires, the high current circuit might get a little warm, but it shouldn't get hot and everything should stay at about the same temperature. Anything getting hotter than the rest is a problem that needs to be fixed before it gets worse.

[cableguy_hd]

http://www.cartsunlimited.net/Custom_Options.html

pck 101 and best I can tell. I think M- goes to the motor. Ill have to check that spot

[cableguy_hd]

cleaned and sprayed M- and its cool to the touch after a long ride. solenoid is still a little warm but that may from the hills we climbed...

[cableguy_hd]

all connections are cool to the tough but the sol. gets hot after rides. normal or what? I tend to check things after every ride. Sunday we went for one on pavement with decent hills but had 700lbs of passengers.

[radioman]

I don't think a proper operating solenoid should get hot. It may be fixing to fail or it may not be heavy duty enough. Contacts are about the only thing could make it get hot. Check the big connections for heat and make sure they are clean and tight. They may have resistance in the connection causing heat and the heat is conducting to the solenoid housing.

[JohnnieB]

The electromagnet that closes the solenoid contacts will generate some heat, but the solenoid body shouldn't get very hot.

Put the rear end of the cart on jackstands so cart won't move and F/R in neutral so motor won't spin.
Run a jumper wire from battery packs main positive terminal to solenoid's small terminal with red wires on it.
That should make solenoid click.

Let it sit that way for and hour or two and check the temperature of the solenoid.
The heat should be from the electromagnet alone.

If it is significantly cooler than what it was after the trip with 700 pound load, the solenoid's big terminals and/or contacts are generating heat (have excessive resistance).
You might need a super-duty (400A) solenoid rather than just a heavy-duty (200A) solenoid for your application.

[cableguy_hd]

Thanks