# KSI relay??



## PerfectAsThis (Aug 3, 2010)

hey did you end up getting the bosch relay? let me know i need one too!!


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## mvest (Jan 22, 2009)

PerfectAsThis said:


> hey did you end up getting the bosch relay? let me know i need one too!!


I did find and use the 
Bosch Micro Relay with Internal Suppression Resistor 
#101-75502 for $6.41 from EVSource. I just finished my '85' S-10 and have about 200 miles on it with no problems. Hope this helps.


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## frodus (Apr 12, 2008)

How is it being used? 12V coil switching pack voltage on its contacts?


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## PerfectAsThis (Aug 3, 2010)

ok thanks. i found a automotive relay off a mazda miata laying around in my garage. will that work? theres 4 pins.
1)green 2)white/red (makes clicking noise)
3)Black/red and 4)white/red

how did you wire the relay? thanks in advance


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## PerfectAsThis (Aug 3, 2010)

congrats on the build btw! you have an ev album?


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## mvest (Jan 22, 2009)

PerfectAsThis said:


> congrats on the build btw! you have an ev album?


I do have an album that's a lil out dated but it is http://www.evalbum.com/preview.php?vid=2319 I hope to put some picts up soon as some of those a not correct. I have changed the configuration of the front electrical components and it is now painted. 
I jsut looked at what I have and unfortunetly its not the Bosch. I used a chinese relay that says OEM 30a/20a 12vdc I have it wired as follows. 
#87a pin not used
#87 pin on relay to the top pin on my Curtis 1231c controller
#30 pin on relay to Main contactor (+) post
#85 pin on relay to Chassis ground
#86 pin on relay to Pot box and a second wire from same pin going to (+) back pin of Main contactor
I also have a diode wired from #85 to #86. 
I hope this helps and thanks for the congrats.


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## frodus (Apr 12, 2008)

so you're switching pack voltage with a 12V rated Relay? Not good practive. Good luck with that.

You SHOULD be using a 12V coil relay with higher voltage rated contacts, like this one:
www.*casadelgato*.com/KUEP-3D55-12
150VDC rated contacts, 10A

are you switching pack voltage through that little microswitch on the throttle too? 

They're rated for 12V too.


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## EVfun (Mar 14, 2010)

If you are using a standard automotive relay, or other relay with contacts only rated for about 30 volts DC, you should include a quencharc to suppress contact arcing and use a relay rated to switch at least 3 amps. The idea is to stop the initial arc and have lots of extra metal mass on the contacts to prevent the contacts from becoming welded. The Curtis manual states that if ksi is switched with a relay the contacts need to be rated for at least 30 milliamps (top of page 12.).


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## mvest (Jan 22, 2009)

I will reply later as I am going to see if this picture thing works


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## mvest (Jan 22, 2009)

Not sure if I follow the question? 
"are you switching pack voltage through that little microswitch on the throttle too?"


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## PerfectAsThis (Aug 3, 2010)

EVfun said:


> If you are using a standard automotive relay, or other relay with contacts only rated for about 30 volts DC, you should include a quencharc to suppress contact arcing and use a relay rated to switch at least 3 amps. The idea is to stop the initial arc and have lots of extra metal mass on the contacts to prevent the contacts from becoming welded. The Curtis manual states that if ksi is switched with a relay the contacts need to be rated for at least 30 milliamps (top of page 12.).




i'm a little confused. so will the bosch relay work as a ksi switch? i already ordered it. should be here soon. 

 

This Bosch 12V, bracket mount SPST relay is rated for 20 amps. It has a suppression resistor across the coil to prevent kickback to the coil-driving circuitry. This eliminates the need for an external coil suppression device.
*Specifications:*


Coil operating current: 154mA
Operating temperature: -40 C to +100 C
Mechanical life: 10,000,000
Motor load (N/O): 15A (30A in-rush), 200,000 cycles
Resistive load: (N/O): 20A, 300,000 cycles


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## mvest (Jan 22, 2009)

Not sure if I understand the question 
"are you switching pack voltage through that little microswitch on the throttle too?"
Can you please eloborate for me? (trust me, I'm not smarter then a 5th grader either)...lol


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## frodus (Apr 12, 2008)

are you switching pack voltage. I don't know how many volts your vehicle is running. The KSI input on a lot of controllers is pack voltage. For example, you have a 144V pack, and your controller requires 144V on the enable pin to get the controller working.

so, you're running +pack through the contacts of the relay and microswitch on your PB-6, into the KSI input on the controller. Are you doing that? or are you giving the controller 12V to enable?


those contacts are rated 12V 20A, not 144V 20A. As you go higher, there's a real problem with arcing, even with low current devices like the enable on a controller. You should check.


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## EVfun (Mar 14, 2010)

PerfectAsThis said:


> i'm a little confused. so will the bosch relay work as a ksi switch? i already ordered it. should be here soon.


It is not actually rated for the DC voltage required but I've seen similar relays used successfully many times. You should include the quencharc I linked to or even just a 1uf capacitor across the contacts (adding the resistor makes it better.)


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## PerfectAsThis (Aug 3, 2010)

frodus said:


> are you switching pack voltage. I don't know how many volts your vehicle is running. The KSI input on a lot of controllers is pack voltage. For example, you have a 144V pack, and your controller requires 144V on the enable pin to get the controller working.
> 
> so, you're running +pack through the contacts of the relay and microswitch on your PB-6, into the KSI input on the controller. Are you doing that? or are you giving the controller 12V to enable?
> 
> ...


i am running 120v. i was going to use the 12v relay to turn on the controller. here is my set up;



 10 12v Gel-Tech batteries. @ 32ah
 Curtis 156v/500a controller (2 throttle imput, 1 KSI, b-,b+,M-)
 Kelly DC-DC converter 120v-12v 25a (input + and - , Output + and -)
 Forklift motor (A1,A2,S1,S2)
 Kilovac contactor 12VDC COIL 200a 320VDC (+A1,-A2 and +,-)
 500a Fuse U*===*C (that's what it looks likes)
 Shunt 75m [o==o]
and the relay
 


i need help with the connecting everything. please help me. i am in no rush at all and i check my mail frequently.


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