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I'm writing a petition on kill switches right now and came across this diagram I made for wiring in a kill switch using the white-rodgers solenoid. 

 

Figured I would share incase it helps any teams doing this also. Hopefully I'm not reposting myself.

 

Solenoid%20Kill%20Switch%20Wiring.jpg?m=

 

 

 

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Idiot. 

Jocularity and levity have no place in a champcar tech thread...

I'm writing a petition on kill switches right now and came across this diagram I made for wiring in a kill switch using the white-rodgers solenoid.    Figured I would share incase it helps a

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18 minutes ago, turbogrill said:

We use a selenoid but have the alternator directly to the battery.

 

While that will pass the champcar tech "test" of killing the car if you interrupt the correct ignition wire, it isn't technically correct.   Its really no different than not having a solenoid and just having a switch on the dash that kills power to the ECU or something.  

 

The battery is supposed to be completely isolated from the car when the kill switch is activated.  If your wire from the alternator got smushed the kill switch would not stop it from arcing.

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16 minutes ago, Chris Huggins said:

While that will pass the champcar tech "test" of killing the car if you interrupt the correct ignition wire, it isn't technically correct.   Its really no different than not having a solenoid and just having a switch on the dash that kills power to the ECU or something.  

 

The battery is supposed to be completely isolated from the car when the kill switch is activated.  If your wire from the alternator got smushed the kill switch would not stop it from arcing.

 

Wouldn't the electrical field in the alternator die when you flip the ignition switch? So there is only a little bit of energy stored in the alternator, same amount that goes thru the resistor.

 

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1 hour ago, Chris Huggins said:

While that will pass the champcar tech "test" of killing the car if you interrupt the correct ignition wire, it isn't technically correct.   Its really no different than not having a solenoid and just having a switch on the dash that kills power to the ECU or something.  

 

The battery is supposed to be completely isolated from the car when the kill switch is activated.  If your wire from the alternator got smushed the kill switch would not stop it from arcing.

But the 100 amp fuse inline at the battery will!

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1 hour ago, turbogrill said:

Wouldn't the electrical field in the alternator die when you flip the ignition switch? So there is only a little bit of energy stored in the alternator, same amount that goes thru the resistor.

But what if you don’t flip the kill switch? That’s a long wire going forward to the engine which is carrying a lot of amps. A short from pinching or rubbing could be bad news. The diagram points to the hot wire from battery with a label “keep this wire as short as possible”.

 

Lets say you wreck the car and the engine shifts and cuts that alternator wire. Doesn’t matter if you turn off the kill switch because you still have a wire from positive into the engine which has now been cut and wasn’t disconnected by your kill switch. 

Edited by enginerd
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Hmmm, do I get into this discussion again? 3rd or 4th time topic on these forums IIRC in the past few years....

Hint: 6 pole switch meets the rule as Huggy described. 

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1 hour ago, enginerd said:

 

 

But what if you don’t flip the kill switch? That’s a long wire going forward to the engine which is carrying a lot of amps. A short from pinching or rubbing could be bad news. The diagram points to the hot wire from battery with a label “keep this wire as short as possible”.

 

Lets say you wreck the car and the engine shifts and cuts that alternator wire. Doesn’t matter if you turn off the kill switch because you still have a wire from positive into the engine which has now been cut and wasn’t disconnected by your kill switch. 

 

Are you assuming the alternator is in the front of the engine and the battery, kill switch is in the back?

 

Then yes, having an extra wire from alternator all the way back to the battery doesn't make sense. Sounds like a waste of weight, amps and safety.

My alternator wire is 1 ft, it's actually shorter going to the battery than the selonoid.

 

 

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1 hour ago, mcoppola said:

Hmmm, do I get into this discussion again? 3rd or 4th time topic on these forums IIRC in the past few years....

Hint: 6 pole switch meets the rule as Huggy described. 


Yeah right, wrong, whatever the bccr says it must kill all power. Sections 3.14.1 and 3.14.2 could probably be tweaked a bit but together they are pretty clear. So if you are going to be compliant with the rules the kill switch must kill all power. 

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1 hour ago, Burningham said:


Yeah right, wrong, whatever the bccr says it must kill all power. Sections 3.14.1 and 3.14.2 could probably be tweaked a bit but together they are pretty clear. So if you are going to be compliant with the rules the kill switch must kill all power. 

Well, killing the ignition will kill the engine which stops the alternator which ‘kills power’ regardless of how the alternator is connected...
I think the rule should be “completely disconnect the positive battery terminal from everything but the wire going to the kill switch.”

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2 hours ago, turbogrill said:

 

Are you assuming the alternator is in the front of the engine and the battery, kill switch is in the back?

 

Then yes, having an extra wire from alternator all the way back to the battery doesn't make sense. Sounds like a waste of weight, amps and safety.

My alternator wire is 1 ft, it's actually shorter going to the battery than the selonoid.

I didn’t consider the placement you have when I responded. My battery (and most others that I have seen) is not located in the engine bay. Mine is in the driver compartment protected from collision within the roll cage. I don’t think it’s good practice in general to have batteries in an area where a wreck would compromise it. 

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22 minutes ago, enginerd said:

I didn’t consider the placement you have when I responded. My battery (and most others that I have seen) is not located in the engine bay. Mine is in the driver compartment protected from collision within the roll cage. I don’t think it’s good practice in general to have batteries in an area where a wreck would compromise it. 

 

Interesting! Mine is in the OEM location, assuming they put it in a safe place. 

 

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7 hours ago, Chris Huggins said:

While that will pass the champcar tech "test" of killing the car if you interrupt the correct ignition wire, it isn't technically correct.   Its really no different than not having a solenoid and just having a switch on the dash that kills power to the ECU or something.  

 

The battery is supposed to be completely isolated from the car when the kill switch is activated.  If your wire from the alternator got smushed the kill switch would not stop it from arcing.

But the 100 amp fuse inline at the battery will! The alternator power wire needs to go to the battery or else you will fry the regulator when you kill it. The engine is still spinning it when you kill the engine, it still produces voltage and will spike causing the electronics in the regulator to fry. The voltage from it has to go somewhere or else this will be the result. The sure fix is to mandate an inline fuse AT the battery to the alternator power wire. Easy and saves frying an alternator or the car if the wire becomes shorted.

Edited by Timothy G. Elliott
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Just now, Timothy G. Elliott said:

But the 100 amp fuse inline at the battery will! The alternator power wire needs to go to the battery or else you will fry the regulator when you kill it. The engine is still spinning it when you kill the engine, it still produces voltage and will spike causing the electronics in the regulator to fry. The voltage from it ha to go somewhere or else this will be the result. The sure fix is to mandate an inline fuse at the battery to the alternator power wire. Easy and saves frying an alternator or the car if the wire becomes shorted.

I have read this argument from many sources, yet I use a 4 pole kill switch which should have this problem but have never fried an alternator... running since 2014.

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8 minutes ago, Timothy G. Elliott said:

But the 100 amp fuse inline at the battery will! The alternator power wire needs to go to the battery or else you will fry the regulator when you kill it. The engine is still spinning it when you kill the engine, it still produces voltage and will spike causing the electronics in the regulator to fry. The voltage from it has to go somewhere or else this will be the result. The sure fix is to mandate an inline fuse AT the battery to the alternator power wire. Easy and saves frying an alternator or the car if the wire becomes shorted.


Which is the purpose of this:

 

 

image.png.bff161fca0366d3c028e90f13ee094b9.png

 

This point has been argued many times in the past. However unless you wire it up where all of the power is not isolated you are not meeting the BCCR. 
 

Look, just wire it up per the bccr, use the resistor, it works. 

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9 minutes ago, Burningham said:


Which is the purpose of this:

 

 

image.png.bff161fca0366d3c028e90f13ee094b9.png

 

This point has been argued many times in the past. However unless you wire it up where all of the power is not isolated you are not meeting the BCCR. 
 

Look, just wire it up per the bccr, use the resistor, it works. 

So what's the problem with an inline fuse at the power source? It makes killing the rest of the power a 2 pole switch which is simpler, I am more concerned about the battery cable going to the switch that has no safety if it shorts, again an in line 245 Amp fuse at the battery corrects that issue from being one!

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4 minutes ago, Timothy G. Elliott said:

So what's the problem with an inline fuse at the power source? It makes killing the rest of the power a 2 pole switch which is simpler, I am more concerned about the battery cable going to the switch that has no safety if it shorts, again an in line 245 Amp fuse at the battery corrects that issue from being one!


I don’t have a problem with it, it just doesn’t meet the bccr as written.

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6 minutes ago, Burningham said:


I don’t have a problem with it, it just doesn’t meet the bccr as written.

My only problem with that wiring is you can't have an external kill switch for fire rescue to access from outside the car with a second for the driver. I have 2 2 pole switch's in series and they kill everything, though the alt power wire, if it got grounded the inline fuse would disconnect it at the battery.

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I think the most important thing with a kill switch is to make sure that the engine + fuel pump is off. And the quality of the installation.

If there is a small current flowing from the alternator for half a second to the battery I don't think that matters. I don't think that is even enough energy to create a spark.

 

 

1 hour ago, oblio125 said:

They put it in a convenient place for a Road car not necessarily a Race car. 

 

But you will have longer wires? The wire from battery to starter is probably the only unfused wire in the car (if you are anal about safety), instead of having that wire being 1 ft it's much longer and would be of bigger risk of getting cut and create an arc.

(The argument above was that long wires are bad)

 

We have a LifePO4, from what I understand they are safe from impact and will explode on impact. But if you have a Lithium Ion maybe they need to be in a box inside the roll cage? (Only problem if it catches on fire it will burn the driver)

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Sorry to sound like a broken record, but other than safety the most important thing about a kill switch is to meet the rules. 
 

Although its not in the rules I think a best practice is to have a breaker at the battery. I have had a 150 amp breaker in my car since 2015 and it has never tripped unless I mistakenly pushed the trip button but its there if its ever needed. 

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I thought as long as you kill the power to the regulator on the alternator it will not keep putting out voltage and charge/run the car.

 

On my setup I have the pos from the battery to the alternator and the alternator to the starter. On the battery Positive goes to the master kill switch. The other side of the master kill switch goes to the switches. Ignition switch goes to the ecu/alternator/coils/fuel injectors, then a switch for the fuel pump, then aux for brake lights,dash and charging station. If the master is cut off all power is turned off to all switches and the car will not run.

 

I would think that is how most systems are done. Someone could have the master kill switch really kill just the coil power or ecu power, but that I would think is not the common way or smart way.

 

Please be careful when writing a petition that might cause a vast majority of teams to change how their car is wired and cause a lot of money and unneeded work. Also, please consider how other organizations have their rules and do not make a rule that will basically ban cars to cross over or even want to come to the series. Basically, be careful of what you write and think about all aspects of the rule long term for all teams and what the effect will be for all of Champcar.

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34 minutes ago, MR2 Biohazard said:

I thought as long as you kill the power to the regulator on the alternator it will not keep putting out voltage and charge/run the car.

 

On my setup I have the pos from the battery to the alternator and the alternator to the starter. On the battery Positive goes to the master kill switch. The other side of the master kill switch goes to the switches. Ignition switch goes to the ecu/alternator/coils/fuel injectors, then a switch for the fuel pump, then aux for brake lights,dash and charging station. If the master is cut off all power is turned off to all switches and the car will not run.

 

I would think that is how most systems are done. Someone could have the master kill switch really kill just the coil power or ecu power, but that I would think is not the common way or smart way.

 

Please be careful when writing a petition that might cause a vast majority of teams to change how their car is wired and cause a lot of money and unneeded work. Also, please consider how other organizations have their rules and do not make a rule that will basically ban cars to cross over or even want to come to the series. Basically, be careful of what you write and think about all aspects of the rule long term for all teams and what the effect will be for all of Champcar.

So your big main 'starter cable' goes battery to alternator to starter and isn't interrupted by the kill switch?

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