turbohatch96y7

iTrader: (15)

Mmmm idk buddy.

You're saying if you remove voltage from the field the alternator will continue to produce voltage?

No.

Maybe you're thinking of a generator?

tepid1

No, you can do it with a 2 pole as well.

And without excitation, the alternator will not make voltage. Even if it's spinning.

lostforawhile

no I said you need to cut off the field, if you just disconnect the battery, voltage is still being introduced into the electrical system

lostforawhile

I understand that, but voltage will still be in the system if just the battery is disconnected, voltage produced will still feed the field unless you cut the field

tepid1

I see what you're trying to say now. Yes, the alternator excitement needs to be cut.

turbohatch96y7

iTrader: (15)

So you are agreeing the solid state option is also inferior?

I don't get it.

Provide the field with its on power source from the same batt.
But that switch will remove voltage from the field faster?

lostforawhile

no, you have two sources of power in the electrical system, the battery and the alternator, just cutting the battery doesn't cut the field, as the alternator is still producing voltage, you need to cut both the battery and the alternator field at the same time, or voltage from the alternator keeps feeding into the system and powering the electrical system and the field, also it can cause a very high voltage spike, cutting the battery without the alternator, and can fry a lot of your electronics, just like disconnecting the battery while the engine is running, something you should never do, the battery load helps keep the alternator voltage under control, along with the regulator. as far as a race car, i wouldn't want to trust anything but a good mechanical switch, if you are the one trapped in the car after a wreck, do you want to trust a switch you can hit and you know everything is dead, or an electronic switch?

turbohatch96y7

iTrader: (15)

You understand how a circuit works, yes?

lostforawhile

well now that you have added the alternator field to the circuit

lostforawhile

for the record I believed you were talking about stock wiring with a cutoff for the battery, no one mentioned moving the field power to behind the cutoff switch, works fine in a race car just dont leave the master on or it will drain the battery

turbohatch96y7

iTrader: (15)

Yeah the output from the alternator should be before the solenoid or ss relay.

I thought that was already implied.

turbohatch96y7

iTrader: (15)

Its not behind the cutoff its in front of it. The solenoid opens no more current to the field and the output from the alternator cant reach the rest of the circuit because its behind the solenoid

tepid1

No. That's not what I am saying or said. Stop being a douche for just a minute. It's clear that you're trying to start a pissing contest.

I've given my personal opinion after having dealt with all this in the past. Take my experience for what it's worth. I'm done and I'm not playing these stupid keyboard warrior games.

I really don't know why I bother with this forum anymore....

turbohatch96y7

iTrader: (15)

I wasn't trying to start a pissing match. LOSTFORAWHILE got everyone confused.

ss relay works. (more expensive, looks cool) ( fails closed)
external switch works (long 4 gauge cable) (can fail open or closed)
12v solenoid works. ( Fails in the closed position)


They all have their flaws

only 100 percent guarantee to cut off power will be a manual pole switch through the bumper.

tepid1

Facts:
SSRs have a > 2 million hr lifespan (on average)
SSR's don't have contacts that suffer from arcing and breakdown
SSR's switch faster than EMR (electromagnetic relays)
SSR's are not prone to vibration issues
SSR's draw close to zero current to operate and pickup their respective contacts

Yes, they fail in a closed state. Let's look at it this way since this is in the drag forum....
In the middle of a race which would you rather have?
A.) A SSR fail closed and you continue to run your car safely.
B.) A EMR fail open and you lose all power to your vehicle, you could lose or you could crash.

A car can be configured many ways, but what if it were to have power steering? What if it had an electric booster or even an electric water pump or vacuum pump. Now you've lost a motor and lost steering.

Not saying it's the only solution, but an SSR really is the BEST current solution. It's expensive, but most of the best parts are. It's like that for a reason.

lostforawhile

I dont think I've ever heard of a quality manual cutoff switch failing and opening, they've been used for decades in racing, yes it's a little more wiring, but the idea if you get in a wreck, you can kill the power NOW, not worry of a SSR is going to stay closed,

lostforawhile

if there was a battery in the back, I would run the positive lead through a switch like the flaming river switch, then to the back and loop it through a bumper switch to the battery, that gives you the option to kill the electrical system before the track workers can even get to you. it's not hard to mount a battery cable well enough in the car to maintain it's integrity in a crash

turbohatch96y7

iTrader: (15)

Aaaand the horse is beat.

I agree with everything you said.

If we stuck with simple things that work where would society be?.

Lock it up

a1320addict

iTrader: (1)

Isn't it typical though - people ask questions, then argue when they get answers they don't like.

Charlie Moua

iTrader: (3)

Sorry for the ignorance, but what is "solid state" mean?


Also what do you consider "cheap" audiostore wiring?
Most of the wiring I planned on using is pretty dense & cost $5 per ft for 0/2 gauge wiring.

Paul_VR6

Sorry for getting back to this so late, but it seems to have gone on without me.

The purpose of the switch is to turn the engine and electrical accessories off and keep them in a safe state (off). You don't need to wire the battery/alt through the switch, just the electrical functions that run off of them. Its a simple difference, but important. and makes the wiring much easier and cheaper. In your example, the fuel pump *should* be wired through the main relay that's cut when the power from the switch is cut. The ECU power will also be cut, so if it's triggered from there, it's also taken care of.

I am well aware that it's safety, but if there is a simpler and less expensive way to do something, I'd be hard pressed to do differently.

For further clarity on what is required, call your local NHRA or IHRA tech inspector. I did.

turbohatch96y7

iTrader: (15)

http://en.wikipedia.org/wiki/Solid-state_relay

Freemananana

iTrader: (3)

I don't think Charlie argued at all though. So other people came to this thread and started arguing amongst themselves. The OP is still quite open to all of this.

Just for me personally: A cutoff switch for the main relay would be effective then, right? I know there should be adequate space to tap into the main relay around the fuse box area.

Paul_VR6

I would say yes as long as the cutoff shuts off the engine, fuel pump(s), water pump, fan(s), etc, etc, etc.

lostforawhile

the point of the cut off switch is to cut off all power, including the battery and alternator in an emergency, crash,fire etc, not to turn off accessories, thats why so many organizations require the external switch, so track workers can kill all power when they are trying to get you out of the car, my personal preference and what I used to run myself, was what I mentioned above, a cockpit mounted cutoff and then also ran through the external cutoff, which is usually required, if I smell smoke in the car or see fire, I'm not worried about whats on or off, I'm going to hit that switch, kill everything, and get the hell out of the car as fast as possible.