# Curtis KSI voltage and Main contactor



## frodus (Apr 12, 2008)

What contactor are you using? (model and manufacturer)

What are the contactor settings in the 1238 (viewed from the handheld)?

Do you have anything hooked up to B+ and B- on the controller?


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## cpct (May 31, 2012)

frodus said:


> What contactor are you using? (model and manufacturer)


I tried a few that we had lying around (can't immediately check manuf. since I'm not on location), but tested them on a bench supply first to make sure that they would not exceed the 2A rating from the manual. I originally used a Tyco EV200 but later read that the economizer circuit could be problematic.
Measured with a multimeter between driver and coil return but both are at KSI voltage.


> What are the contactor settings in the 1238 (viewed from the handheld)?


I toyed a bit with the Main Contactor settings under Drivers without sucess. Currently I have:

Main Enable: on
Pull In Voltage: 50%
Holding Voltage: 50%
Battery voltage compensated: on (off made no difference)
Interlock type: 2
Checks enable: on (off made no difference, except that it detected disconnected contactor)
Main DNC Treshold: 0
Precharge: on (off made no difference, but makes me wonder whether it precharges using the KSI voltage. At 24V, the capacitors would never get precharged up to 96V)


> Do you have anything hooked up to B+ and B- on the controller?


Currently nothing connected


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## frodus (Apr 12, 2008)

Thats why.

The controller does its own precharge. You need B- hooked up to Pack ground, B+ is hooked to one side of the contactor, and the battery + hooked to the other side of the contactor. 

The controller uses B- and KSI to precharge the Capacitors in the controller. Once the programmed voltage has been reached, the controller looks for any other faults, and if all is clear, it shuts the contactor. Since you have no battery and nothing hooked to B-, it won't precharge. Its also possible that your pack volage cutout is causing an error.

These are pretty smart controllers and they won't close the contactor if you haven't wired it correctly, the battery is too high, the battery is too low or there is no battery.


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## cpct (May 31, 2012)

frodus said:


> Thats why.
> 
> The controller does its own precharge. You need B- hooked up to Pack ground, B+ is hooked to one side of the contactor, and the battery + hooked to the other side of the contactor.
> 
> ...


We will try with a 100V power supply in a few days, then we'll know for sure. Still, I wanted to get a few things running before that.

Even when disabling the precharge function, the contactor does not close. Also, since no faults are reported it would seem to me that the controller does not check KSI and/or capacitor voltage.


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## frodus (Apr 12, 2008)

Hook it up like it's supposed to be hooked up and with th. Correct voltage and it will work. Don't expect to get it working otherwise.


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## cpct (May 31, 2012)

Okay, got it working on Saturday. The problem was with the contactors, they were too slow to close. The Curtis only tries briefly, then waits half a second, repeat.


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## frodus (Apr 12, 2008)

What voltage are the contactor coils?


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## cpct (May 31, 2012)

frodus said:


> What voltage are the contactor coils?


The biggest one was 48V. At some point it was very quiet and I could just hear the whine of its coil when the Curtis was trying to close it.

Now I put in a relatively tiny 24V one and it worked immediately. Will have to find a work around for the EV200 though, maybe with a small 12V car relay inbetween.


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## frodus (Apr 12, 2008)

If you are trying to use a 48V contactor, but only giving the controller 24V, *its a wonder it closed at all!* You said that the Pull in voltage is 50% (as well as holding). That means 12V was going to the 48V contactor.


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## cpct (May 31, 2012)

frodus said:


> If you are trying to use a 48V contactor, but only giving the controller 24V, *its a wonder it closed at all!* You said that the Pull in voltage is 50% (as well as holding). That means 12V was going to the 48V contactor.


Yes, but the "Battery Voltage Compensated" option should take care of that. Theoretically, it should then go to 100%. As you say, that would still make 24V at most.
However, I also tried other contactors at 12 and 24V, but at that time it didn't work and I have no idea why. The programmer also never showed a fault.
Anyway, with the 100V supply now sorted it behaves as it should


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## frodus (Apr 12, 2008)

It will only buck, not boost. So 24V in, thats the most you'll get out, so 1/2 the rated coil voltage of the contactor, which would explain why the contactor closed slowly.


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## EV2012 (Oct 13, 2012)

Hi,

I have just a similar problem with my curtis controller 1238-7601 and I need some help.
I connected a Gigavac GX14BCB contactor. It´s coil voltage is 12V.

The problem is that the controller doesn´t close the contactor, which is connected to KSI coil return (-) and Driver1 (+). B- and B+ are connected.
Precharge is working, because after closing KSI switch, there are about 102V on main contactor on controller side.

The controller voltage on KSI is approx. 108V. So I need a 11% duty cycle to get 12V, right?

But in datasheet of the contactor is written:
"Contactor has two coils. Both are used for pick-up, and 
then in approximately 75 milliseconds, one coil is electronically 
removed from the coil drive circuit. The remaining coil supplies 
low continuous hold power sufficient for the contactor to meet 
all of its specified performance specifications. This provides low 
coil power without PWM electronics that can cause EMI emissions 
and/or cross-talk on control power."

So, I think that I need 12V with 100% duty cycle that the contactor is working. But I don´t know how ...

Thanks for your help in advance!


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## major (Apr 4, 2008)

How do you have the Curtis parameter set for coil driver 1?


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## cpct (May 31, 2012)

The Gigavac you have also has a kind of "economizer" that reduces the holding current. In our tests, combined with the Curtis economizer, this behaves flaky at best.
You can try to set the holding voltage in the curtis the same as pull in voltage (11-15%) and putting a capacitor over the coil's connections to filter the PWM. For us, this worked for a 12V car relay, which in turn switches two Kilovac contactors located at our battery packs. YMMV


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## frodus (Apr 12, 2008)

Its better to use the recomended contactor from HPEVS, in this case its the LEV200. Contactors that have economizers or control circuitry built-in do not work well with controllers like Sevcon or Curtis AC units that use PWM to control the contactor. The PWM interferes with the contactor control circuitry.

The thing is, the Curtis and Sevcon are usually set up to reduce holding current once they're engaged, So in a way, you're doing the same thing.


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## Hippie Djohn (Oct 24, 2011)

I went for the Albright contactors. 

http://www.albrightinternational.com/lang/en/index.html

MUCH beefier and cheaper than the others.
Ratings are conservative compared with the TYCO's, the tips on the SU280B ( http://www.albrightinternational.com/files/downloads/catalogues/SU280.pdf ) are 2-3 times bigger than those Kilovac EV200

Don't know if you are able to get them in US ?


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## EV2012 (Oct 13, 2012)

Thank you very much for your help!

So these are bad news for me, because I already installed the GX14 contactor with 70mm² cables in a small box and the HV terminals are very different to LEV200 ....
I was assuming that the PWM is a 12V signal which I can switch to 100% PWM

There is nothing else for it but to replace the contactor by a LEV200. 

And thanks for the hint to Albright contactors. I already considered it, but I think the voltage of 96V is borderline.


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## frodus (Apr 12, 2008)

Get a 48V LEV200 and use the programmer to adjust the PWM up a little. HPEVS switched from 24V to 48V in the last couple of years. Just don't get a 12V one, they buzz.


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## EV2012 (Oct 13, 2012)

Okay, thanks! I will try to get a 48V one.


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## Hippie Djohn (Oct 24, 2011)

EV2012 said:


> And thanks for the hint to Albright contactors. I already considered it, but I think the voltage of 96V is borderline.


It is no problem to run the Albrights at 140V.

Look at these pictures for the EV200 how poor quality they are if you open one up.


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## EV2012 (Oct 13, 2012)

Hippie Djohn said:


> It is no problem to run the Albrights at 140V.
> 
> Look at these pictures for the EV200 how poor quality they are if you open one up.
> 
> ...


Yes, I also opend a LEV200. I assume your LEV in your pictures had welded contacts?

The difference between the Albrights and the LEV is that the LEV is filled with hydrogen to prevent sparks and therefore welded contacts.
There are also 2 magnets to deflect the sparks.


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## Hippie Djohn (Oct 24, 2011)

There is nothing that makes the EV200 more capable of carrying higher voltages than the Albright.


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## EV2012 (Oct 13, 2012)

Hippie Djohn said:


> There is nothing that makes the EV200 more capable of carrying higher voltages than the Albright.


I think the hydrogen and the magnets will allow higher voltages.


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## Hippie Djohn (Oct 24, 2011)

EV2012 said:


> Yes, I also opend a LEV200. I assume your LEV in your pictures had welded contacts?
> 
> The difference between the Albrights and the LEV is that the LEV is filled with hydrogen to prevent sparks and therefore welded contacts.
> There are also 2 magnets to deflect the sparks.


Yes it welded...

Never had a welded Albright, it also has magnetic blowout.
Coil is MUCH more powerful on the Albright and makes the contact between the tips better.


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## Hippie Djohn (Oct 24, 2011)

As long as you pre-charge and don't open it during load it doesn't matter.
Distance between tips is also bigger on Albright to prevent arcing.

It's your call.. I use the Albright up to 140V without problems.


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## EV2012 (Oct 13, 2012)

Hippie Djohn said:


> Yes it welded...
> 
> Never had a welded Albright, it also has magnetic blowout.
> Coil is MUCH more powerful on the Albright and makes the contact between the tips better.


You are right, I will consider the Albright as well, beacuse the LEV is really expensive ....


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## major (Apr 4, 2008)

Hippie Djohn said:


> Look at these pictures for the EV200 how poor quality they are if you open one up.


That appears to be an application problem; not a quality problem.


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## Hippie Djohn (Oct 24, 2011)

major said:


> That appears to be an application problem; not a quality problem.


Correct.. but that doesn't change the facts...


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## Hippie Djohn (Oct 24, 2011)

This is an Albright SU80 for a golfcar, 48V, 300A
Even this one seems more beefy than the EV200



















Terminals are M8 (almost same size as 5/16) for size comparison.


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## EV2012 (Oct 13, 2012)

Thank you very much for the pictures! 
I will try to get an Albright contactor.


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