# High Pedal Lockout Problem



## KiwiEV (Jul 26, 2007)

Hi Folks, 

Here's a question for you using a Curtis Controller and a Curtis Potbox.
I'm using one contactor. and at the moment, when I put my foot on the gas, the contactor clicks on. Then when I take my foot off the gas, the contactor clicks off. This is good.
Problem is, the high-pedal disable doesn't seem to work. For example, when I put my foot hard down and turn on the ignition, CLICK! the contactor turns on. This is bad.

Is this what the coil suppression diode is for, or is that the job of the potbox's lockout switch?
And, what is the correct diode to use on my Albright (12V coil) contactor?
What's the purpose of the diode anyway?


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## veperformance (Aug 17, 2007)

i'm not familiar with that controller but i can assure you that a diode is a must on a coil to absorb the return current when power supply is interrupted at the coil.


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## KiwiEV (Jul 26, 2007)

Ok, thanks for that. That explains the diode!
I'm still trying to figure out why the high pedal lockout isn't working though.
Interestingly, I received a normal 12V switching relay with the controller with no instructions, I'm assuming this has something to do with the high pedal lockout?

I just don't know. I've been scratching my head for hours over this now.
Help!


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## veperformance (Aug 17, 2007)

if you have a diagram i might be able to help.


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## KiwiEV (Jul 26, 2007)

No need to panic. I just heard back from EVA and the High Pedal Lockout is a function built into the Curtis controller. It's not something I need to physically install myself. Phew.
Hope that helps anyone else with the same problem some day!


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## CPLTECH (Sep 14, 2007)

*Re: Purpose of diode*

Purpose of a diode is to absorb the kick back voltage spike only when the coil is de-energized.
The diode polarity must be observed by orienting the “band” end to the positive (+) wire that attaches to the coil. (The coil does not care which is + or --, but the diode does).

Once you let the smoke out, the diode is no longer any good. 

 RE: _I'm using one contactor. And at the moment, when I put my foot on the gas, the contactor clicks on. Then when I take my foot off the gas, the contactor clicks off. This is good._

Is that healthy for the life of the controller??? Mine doesn’t.


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## KiwiEV (Jul 26, 2007)

As far as I can tell, every conversion is different. In this case I spoke to two other converters who say that's normal. 
Either way I can stop worrying now.


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## CPLTECH (Sep 14, 2007)

*Re: Pre-Charge resistor*

I knew I had read something about a resitor across the contacts. Found it in a Curtis 1231 manual. Wasn't quite what I originally posted, but here it is:

*The rapid charging of the controller's internal filter capacitors causes a high inrush current to flow briefly when the contactor closes. To extend contact life, a precharge resistor is recommended; the resistor precharges the capacitors and reduces the inrush current through the contacts. If an inexpensive "can" type solenoid is used, the resistor is mandatory to prevent contact welding. *750 ohm/25 watt.​


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## Nick Smith (Oct 26, 2007)

Hi Gav

Have you got this sorted yet? There is a simple way to do this with one relay placed just before the microswitch on the potbox. 

I could wire this up for you when I come down or alternately I will send you the diagram if you wish.

Cheers

Nick


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## Nick Smith (Oct 26, 2007)

*Re: Pre-Charge resistor*

Hi CPLTECH. As gav is only using one contactor the resistor across it is not a good idea as it will allow pack voltage across the contactor when the car is off - hence he has omitted it. As far as I can determine the resistor is there to prolong the life of the contacts and prevent "welding". Gav's albright contactor is a quality piece of gear and should last a while without the resistor.

Likewise, as I understand it, the diode is only really required where you are using pack voltage to power the coil. Most EV'ers will be using 12V coils but forklifts for instance do use 12, 24, 36, 48 etc. coils powered directly from the pack. That being said, I am being conservative and have fitted diodes anyway.

Cheers, Nick


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## KiwiEV (Jul 26, 2007)

Cheers Nick, I think I've got it sorted now but I still invite you to poke it with a stick when you come down to sunny (well it is at this instant) New Plymouth.


I'm using a diode on the contactor and I've noticed that when it disengages there's a split second delay (barely noticeable) between you cutting the power and the contactor un-clicking. This microsecond delay isn't there when the diode is removed. It's an interesting curiosity for those with spare time to think about. 

On a side note, have a look at this diagram of a proposed basic wiring plan to the controller:








I'm a little concerned about the markings on the terminals of the Curtis Controller. It asks for "Battery +" and "Battery -" and if it's being literal then in theory my cabling in the picture is correct. 
Have a look and let me know what you all think folks.


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## kittydog42 (Sep 18, 2007)

If you look at the manual that I linked on my thread 'New Product / Idea', it shows an example wiring diagram on the last page that shows a complete high voltage layout. Without showing the motor or contactors, your layout looks pretty good, though. Note that the controller switches the battery - to the motor to control the speed, but if you don't have the high pedal disable feature, then it does not really matter which side of the battery that you switch with the contactor, though it is safer to use some sort of redundancy and maybe switch both.


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## Coley (Jul 26, 2007)

The resister is recommended for protection of your controller, more so, than the contactor.

Alltrax recommened a 1000 ohm & 50 watt on my 7245 controller.

I also use a set of solenoids (rated at 96 volts combined) to cut off the neg side of the pack. This shuts off the feed through the resister.

At the 1000 mile mark it is doing fine.


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## KiwiEV (Jul 26, 2007)

Thanks for the input guys. 
I will have the High Pedal Lockout in the car (one of the NZ rules). I still can't find documentation anywhere for the purpose of the resistor other than a contactor protector though.

I was wondering if I should wire it so that the contactor clicks on and stays on when you turn the ignition. The high pedal lockout will still work (as it's built into the controller apparently) but by having the contactor click on with no load on the circuit (as opposed to clicking on when my foot presses down) it would be much gentler on the contactor/controller.

Also, what should go through the circuit first in my circuit box? Does it really matter as it's a complete circuit anyway?

Please put these in order: (from final battery to) Circuit Breaker + Shunt + Fuse + Contactor (to controller)

I'd really like people's input for that part!


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