06 PDS Motor Overheating

[tys454]

I need some help.... my cart is shutting down due to motor overheating apparently. It has a new DCX400 . It was doing this before the new controller was installed and I was told that the overheating was due to the controller so I had a new one installed. It overheats at about a 2-3 mile trip with 2 people on board. Not going wide open or anything. Using it around the hunting camp. No long grass. Do you think the motor needs to be changed?

[kgsc]

Will the cart roll freely with the brakes off? If so, your motor may have some issues. May just be dirty but if you are going to go through the trouble to pull it I would look into getting it rebuilt.

[tys454]

It does roll but not freely its got some drag to it.

[tys454]

I guess I should've said it rolled bc we hooked a 4wheeler to it and dragged it for 3 miles. Pretty pissed off when you're stuck in the woods getting eaten alive by mosquitos .

[kgsc]

Been there. Hopefully you switched it to Tow first. You may have brakes dragging, the differential, a bearing or the motor itself. Time to put it on some jack stands, pull the wheels and find the issue.

[JohnnieB]

Originally Posted by tys454

I need some help.... my cart is shutting down due to motor overheating apparently. It has a new DCX400 . It was doing this before the new controller was installed and I was told that the overheating was due to the controller so I had a new one installed. It overheats at about a 2-3 mile trip with 2 people on board. Not going wide open or anything. Using it around the hunting camp. No long grass. Do you think the motor needs to be changed?

An overheated motor won't shut down a cart, but an overheated controller will.

More correctly, a motor can be overheated to failure, but once it fails, it doesn't run again and it often takes the controller out if it fails during operation.

In other words, whatever was overheating your old controller is now overheating your new controller.

Just the 22" tires alone are enough to overheat a stock PDS controller, but within the capabilities of a DCX400 controller, so I suspect your cart has excessive mechanical drag, causing the motor to draw higher than normal amps to propel the cart at any given speed, which in turn overheats the controller.

As kgsc mentioned, it could be dragging brakes, bad bearings (axle, differential and/or motor), but it could also be the type of tires on cart. (Low pressure tires tend to be amp hogs)

Could also be the the oil in the differential has turned to glue.


Also, what field map are you running in the DCX400?

Do you have Turbo turned on?

How slow were you going on the trip?
(With 22" tires and a stock PDS motor, 5.5 MPH is about as slow as you want to go for an extended period of time.)

[tys454]

Originally Posted by JohnnieB

An overheated motor won't shut down a cart, but an overheated controller will.

More correctly, a motor can be overheated to failure, but once it fails, it doesn't run again and it often takes the controller out if it fails during operation.

In other words, whatever was overheating your old controller is now overheating your new controller.

Just the 22" tires alone are enough to overheat a stock PDS controller, but within the capabilities of a DCX400 controller, so I suspect your cart has excessive mechanical drag, causing the motor to draw higher than normal amps to propel the cart at any given speed, which in turn overheats the controller.

As kgsc mentioned, it could be dragging brakes, bad bearings (axle, differential and/or motor), but it could also be the type of tires on cart. (Low pressure tires tend to be amp hogs)

Could also be the the oil in the differential has turned to glue.


Also, what field map are you running in the DCX400?

Do you have Turbo turned on?

How slow were you going on the trip?
(With 22" tires and a stock PDS motor, 5.5 MPH is about as slow as you want to go for an extended period of time.)

The reason I said the motor was overheating is because it was so hot that you could've fried an egg on it. The controller was not hot nor the wires. The cart did this before the 22s and the new controller. Although it seems it would happen a little faster with the 22s. I do not know where the settings are on the controller, I guess its still on factory settings since the cart shop installed it.

I jacked it up today and the tires spin freely with no drag, and I took the cover off the diff and it is full of glitter. Do not see any gear teeth missing, everything looks fine.

Once the cart is back on the ground with oil you can hear something clicking in the back but I dont see anything wrong with the gears, not sure if its something with motor. I rotated tires in the air and it doesn't make the noise.

[smokey tennis shoe]

If you were just slowly creeping along, that is not good on the motor.

[tys454]

I would say I was not going no slower than 5mph no more then 10mph would it be better to put a higher torque motor?

[JohnnieB]

The max recommended operating temperature for the Class-H insulation of the Field and Armature windings of a stock PDS motor is 356°F, but there are no provisions for measuring the actual winding temperatures, so winding temperature is measured indirectly at the motor's case. When indirectly measured at the case, the max recommended temperature is 239°F.

Chicken eggs can be cooked at temperatures less than 160°F, so a motor can get hot enough to fry an egg without overheating.

Motors can and do get mighty hot because all the amps that pass through them that aren't converted into mechanical motion (Torque) are converted into heat (Watts).

Controllers get hot also. The MOSFETs are not perfect conductors and in a DCX400 they drop about 0.1V for every 100A of current flowing through them. When passing the controller's max current (400A), about 40W of heat is being generated and when the M-buss the MOSFETs are attached to reaches about 200°F, the controller stops passing amps to the motor and starts flashing an error code (LED flashes red 4 time, pauses then repeats).

The next time the cart shuts down, take a look at the LED on the DCX400.

------------
Quick check for excessive mechanical drag:

What if the cart's top speed on a hard level surface?

A PDS cart with a stock motor, stock differential gears (12.44:1) and stock height tires (18") with a DCX400 installed will do 24MPH at 36V.

Increasing the tire height to 22" increases the top speed to 29.3 MPH mathematically.

If your cart's tops speed isn't pretty close to 29MPH, you have excessive mechanical drag.

---------------
A high-torque motor would offset the torque loss of the 22" tire height.

The D&D ES-76-51 I run has about the same RPM for voltage applied as a stock PDS motor and about 30% more torque, while an ES-63-49 is a bit slower, but has 40% more torque than a stock PDS motor. Plus there are several other motor options available.