I have a speed controller that is indicating that it is overheating on trips over about 10 minutes or on hills.
It is a Curtis 1231C that is mounted in the grill where the radiator was located. I also put a small fan in front of the aluminum plate that is used as the heat sink, to supplement the airflow.
The motor is an Advance DC FB1-4001
It is a 144V system.
The max temp that I have found on the heat sink and the controller is 109 degrees F.
The curtis manual states that overheating is 185F internal temp.
Does it seem likely the internal and external temp difference is 76 degrees.
I would like any thought.
Thanks Joel
Did you put the die electric grease between the controller and the aluminum plate? It is used for heat transfer in conjunction with the fan.
Yes, I used heat sink compound between the controller and the aluminum plate. I used a generous amount.
How is the plate mounted to a board? or directly to the car? If you mount it to a board and use a nut inbetween the board and the mounts to the plate cut out the board where the fan is mount the fan to the board it will force air flow around the controller. Also if you used a wire that is too small it could cause a build up of heat and possibly transfer it to the controller, like a narrow spot in a stream the water flows faster, with amperage it causes heat, just a thought. Bob
Thanks for your input. I used 2/0 wire. I check the temp at the connections. It was just above ambient temp. I like the mounting idea except it would allow rain water to contact the speed control. The plate is right up front in the grill.
I am going to try a finned heat sink. If that doesn’t work, I will reconfigure my layout utilizing your mounting Idea.
Thanks Joel
You could put in a baffle before the fan to prevent the water from getting in, a added solid plate and nuts shimming the fan out away from the plate so air could get into the fan and then to the controller. Glad to be able to help. new dawn, as in the dawning of a new era.:D:D:cool:
[QUOTE=37fordelectric;5010]I have a speed controller that is indicating that it is overheating on trips over about 10 minutes or on hills.
It is a Curtis 1231C that is mounted in the grill where the radiator was located. I also put a small fan in front of the aluminum plate that is used as the heat sink, to supplement the airflow.
The motor is an Advance DC FB1-4001
It is a 144V system.
The max temp that I have found on the heat sink and the controller is 109 degrees F.
The curtis manual states that overheating is 185F internal temp.
Does it seem likely the internal and external temp difference is 76 degrees.
I would like any thought.
Thanks Joel[/QUOTE]
Unfortunately, Curtis AC Controllers are notoriously difficult to cool. The Curtis office in Amsterdam tried for two weeks to get a 1238 to behave and gave up. Poor design. The heat sink is large, but heats up in about two minutes on a small hill and the output drops to about 10% of nominal. Unless you want to add a water/glycol cooling systems, radiator, pumps, plenum, I would try another brand, or switch to DC motors and controllers. I highly recommend Logisystems in Texas. I have 18 years experience building EV’s and the DC units work fine. The AC controllers are terrible in non-arctic weather conditions. Of course, you could move to flat land and have less problems.
[QUOTE=37fordelectric;5016]Yes, I used heat sink compound between the controller and the aluminum plate. I used a generous amount.[/QUOTE]
I have tried aluminum and steel. I have spaced it to let air flow under it. I have mounted fans below the aluminum base plate and above the black plastic housing. I have dropped the throttle resistance by 30%. I have used 2/0 wire less than 2 feet long to the motor.
The bottom line is that Curtis does not know how to make AC controllers that will stay cool. Their DC units work fine, but the AC units are for decoration only. Highway vehicles that don’t utilize water-cooled controllers need to remain DC powered.
You’ll save about $3,000 per vehicle and get many years of trouble-free, high-speed operation from a good DC motor like a Warp 8 or Warp 9. My 144VDC EV has been running for 15 years on the same brushes and will still lay 40 feet of rubber and go 100 miles per hour. Controller? Cool to the touch.