# Curtis AC Motor Controller?



## Sunking (Aug 10, 2009)

Hey all I am converting a golf cart to AC with LFP batteries. I will be using the HPEV AC-9 motor with a Curtis 550 Amp controller package. The controller will be programmed for me by HPEV. 

Although the controller will already be programmed, with me being curious, tinkerer, and a Engineer I gotta look inside to see what I can tweak. For one HPEV will only send it with 5200 RPM or 35 mph limit. So the motor will be governed with 1800 more RPM's. The motors maximum continuous HP and Torque occur at 6900 to 7000 RPM's.

So here is my question. Anyone hacked, wrote a program, or purchased software to program the controllers?


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## major (Apr 4, 2008)

Sunking said:


> The motors maximum continuous HP and Torque occur at 6900 to 7000 RPM's.


Where do you come up with that  Peak power is near base speed about 3000 RPM and peak torque is available from zero up to that base speed.

And Curtis is sensitive about their priority software needed to communicate with their controllers. You typically need to buy or rent the programmer dongle. Of course once you buy the product, you can do whatever you want with it. But I don't see folks sharing hacks for it.


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## Sunking (Aug 10, 2009)

major said:


> Where do you come up with that  Peak power is near base speed about 3000 RPM and peak torque is available from zero up to that base speed.


I think we are talking Apples and Oranges. You are correct Peak HP occurs at around 3000 RPM, no argument here. But I was referring to CONTINUOUS HP which occurs near Red Line of 6000 RPM. I get it straight from HPEV Power Graphs. 

Anyway thank you as you have been a great help.


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## major (Apr 4, 2008)

Sunking said:


> I think we are talking Apples and Oranges. You are correct Peak HP occurs at around 3000 RPM, no argument here. But I was referring to CONTINUOUS HP which occurs near Red Line of 6000 RPM. I get it straight from HPEV Power Graphs.


For a continuous power output, yes, that indicates about 10 HP at 6000 RPM. This is obviously related to the condition "Vented Fan Cooled" as stated in red on the graph. Note that maximum continuous torque is back around 4000 RPM at 10-11 lbft. These are thermal limitation rating values, not peak performance values. If you needed to run the motor at 10 HP continuously you gear it such that it would run at 6000 RPM. But I don't think you have much choice with the GC axles for ratio, do you?

For reference, peak performance values can be found on this graph: http://www.hpevs.com/Site/images/to...volt 450 amp imperial peak graph 10-10-12.pdf


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## Sunking (Aug 10, 2009)

major said:


> But I don't think you have much choice with the GC axles for ratio, do you?


Well actually I do. Pretty much anything from 15:1 up to 5:1. For my application using 8:1 with 10 inch radius tires works out to 4700 RPM @ 35 mph. That leaves 2300 RPM to play with to 7000 RPM.


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## dcb (Dec 5, 2009)

Sunking said:


> anything from 15:1 up to 5:1


Umm... is the controller connected to an external vehicle speed signal? Why is it limited to 35mph if not and you have multiple gear ratios available? or why don't you just fake out the vehicle speed signal if so and not worry about the extra rpm (and just shift gears), create an mph signal based on motor rpm and feed it to the controller? Or is this like a chain and sprockets thing?

edit: why are you giving your money to hpev for a crippled controller anyway? Well, it isn't that crippled I guess, at 5200 it looks like you are 1/2 hp away from peak hp.

If you have done the drag analysis and determined your gearing for max top speed, then you are pretty much there. aero drag is exponential, so everything to the right of that hp knee at 6000 rpm isn't terribly useful IMHO.


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## Sunking (Aug 10, 2009)

dcb said:


> Umm... is the controller connected to an external vehicle speed signal? Why is it limited to 35mph if not and you have multiple gear ratios available? or why don't you just fake out the vehicle speed signal if so and not worry about the extra rpm (and just shift gears), create an mph signal based on motor rpm and feed it to the controller? Or is this like a chain and sprockets thing?


Well not sure I understand all your questions, and since I have never worked with this speed controller, not sure I know enough to answer your questions but I will give my best shot. 

This is a electric Golf Cart, or I should say a Donor Cart. I am removing the DC motor, controller, and FLA batteries. They motor will be replaced with an Induction 3-Phase AC motor (HPEV AC-9) a Curtis 1238-5601 controller, and 16S 100 AH LFP battery.

Since it is an AC Induction Motor with a VFD the controller knows the Motor RPM. There are no gears to speak of because it is direct drive with a 8:1 gear ratio, thus RPM and Speed are directly related. The controller can be programmed to limit speed. In fact there is a Speed Switch for Golf/Street. Golf is limited to 15 mph and Street can be as high as I want up to 7000 RPM assuming the motor has enough torque to get to and hold 7000 RPM. 

So what it boils down to is I control the speed by gear ratio and tire size radius. When I started this I did not know exactly what to look for in Motors. I knew it was going to take around 5000 to 6000 RPM's to get where I want to go. At this point I am fairly confident the AC-9 is up to the task according to HPEV rep I have consulted with. 

This is going to be dual purpose Golf Cart and NEV.


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## dcb (Dec 5, 2009)

Sunking said:


> ...For one HPEV will only send it with 5200 RPM or 35 mph limit.





Sunking said:


> The controller can be programmed to limit speed. In fact there is a Speed Switch for Golf/Street. Golf is limited to 15 mph and Street can be as high as I want up to 7000 RPM.


It seems like one of these statements isn't true, or I'm missing something.


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## Sunking (Aug 10, 2009)

dcb said:


> It seems like one of these statements isn't true, or I'm missing something.


Yep you are missing something. Liability.....

HPEV does not want to send it out to max RPM, but I can change it.


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## dcb (Dec 5, 2009)

Sunking said:


> but I can change it.


I'm still lost, you mean like with a jumper or a switch? you don't need to hack the flash or anything like that?


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## Sunking (Aug 10, 2009)

dcb said:


> I'm still lost, you mean like with a jumper or a switch? you don't need to hack the flash or anything like that?


Its all software in the controller thus the title of the thread. 

I am asking if anyone knows of a program that can be used on a laptop. As of now only way to program them is with the very expensive Curtis Programmer. I can always take it to a cart shop as all of them have the Programmer because even stock factory golf carts use Curtis Controllers


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## Ivansgarage (Sep 3, 2011)

Sunking said:


> Yep you are missing something. Liability.....
> 
> HPEV does not want to send it out to max RPM, but I can change it.


I bet you can't change it, even with a programmer. HPEV (vcl) sets and holds the programming so certain parameters can't be changed.

I program Curtis Controllers for my motors and do not use HPEVS (vcl)
because they have pre set parameters for there motors. (ONLY)

HPEVS writes there own vcl so peoples can't screw it up to bad...

Make sense?

Ivan


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## Ivansgarage (Sep 3, 2011)

OK further explain Curtis Controller software..

Curtis has a basic operating system installed on there controllers,
there basic system will run a motor and (optomize) a motor.
It has all basic parameters for setting up a motor, motor temp, controller temp, throttle setting and such....

HPEV comes along and adds a vcl (that they wrote) with all there motor parameters, spy glass, and UN changeable parameters, this stops you from screwing up the motor and yelling at HPEV that is does not work.

If you want to change all this stuff, you can get a controller from HPEV
with NO HPEV vcl but you are on your own.. NO warranty, NO help.
So you best know what you are doing.

Ivan


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