eleckky question
eleckky question
Battery is now at the back in a box (have to tidy the cable up a little with some holders) with a switch to the earth side so I can isolate the battery. Got a surprise when I tried it out with the engine running tonight, switched off the earth and the engine kept running. Even with the battery isolated from the circuit - How the Feck does that happen? Shouldnt this kill everything?
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Moriarty
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Re: eleckky question
Heath wrote:Battery is now at the back in a box (have to tidy the cable up a little with some holders) with a switch to the earth side so I can isolate the battery. Got a surprise when I tried it out with the engine running tonight, switched off the earth and the engine kept running. Even with the battery isolated from the circuit - How the Feck does that happen? Shouldnt this kill everything?
nope, you are running off the charging circuit. you are not interrupting the ignition circuit by breaking the batt earth line.
even breaking both earth and live line of the battery is not actually breaking the ign circuit.
B. (Somebody will shoot me down for this)
Re: eleckky question
So how do I kill everything with the emergency stop / isolating switch? Do I need a relay to the neg side of the alternator that is "livened" off the the isolator switch?
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Moriarty
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Re: eleckky question
Heath wrote:So how do I kill everything with the emergency stop / isolating switch? Do I need a relay to the neg side of the alternator that is "livened" off the the isolator switch?
Are you intending to break BOTH sides of the battery in a "kill" situation?
If so, take a heavy cable ( to prevent voltage drop) from the Alternator direct to the battery.
insert the breaker for the RED line and take ALL services from the SWITCHED side of the breaker.
Run ANOTHER HEAVY red line to the engine bay for this purpose.
Keep it as simple as possible. If you ARE using a two pole breaker, the BLACK line is easy. make damn sure you got good earth connections too. would also help to run a nice heavy black line up to the engine bay as well. nothing to lose, is there?
Re: eleckky question
Why don't you just make a kill switch from the ignition barrel and leave the rest of the wires there? Nice and easy... and that big cable aint cheap
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Moriarty
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Re: eleckky question
gimmemud wrote:Why don't you just make a kill switch from the ignition barrel and leave the rest of the wires there? Nice and easy... and that big cable aint cheap
sure, that big cable isnt, I tend to forget that bit cos I have good deal.
BUT, what price safety?
and, dumbass me, to do it proper, Heath would need a 3 pole switch, also not cheap. the third pole is for the ign circuit. else he is still gonna have it running on the alternator current.
Cheap way?
leave the earth connected, a 2 pole switch. one leg for the main feed and the other in SERIES with the ign switch.
Re: eleckky question
I decided to find a big stop button and fit that to the dash in the future if I can get one free (the old man is going to search his work place for an unused one) with the ignition circuit through that. Then in a problem it is just one big button. Was going to play with individual switches for fuel, ign and fan but may get too complicated (K.I.S.S.), so one on off ign and one for the fan circuit. Might wire the fan up today, no idea what ampage it draws but I have a spotlight loom (switch, wires, relay) I got for 10 bucks from super chump so that will do. What size fuse should I run (yeah I know piece of string length question) - Ballpark figure will do?
Re: eleckky question
Im running an Battery isolator switch(Spark free Marine Sealed) on the positive side of the battery. Switch is located next to battery in the back. 120A Circuit breaker inline after the switch. (from Jaycar)
This is for isolating the battery only. For safety, works, etc
Kill switch is a big red push button type switch that is mounted on the dash. This is wired into the ignition circuit at the ignition barrel. This kills power to the alternator, coil, fuel solenoid and in your case the fuel pump.
Engine wont even start unless the switch is pulled out.
I would normally switch the negative side of the circuit to eliminate surges and sparking .
Means you cant kill the engine fast when required and isolate the battery for safety etc.
My electric fan keept blowing 20A fuses so im upgrading to 30A
This is for isolating the battery only. For safety, works, etc
Kill switch is a big red push button type switch that is mounted on the dash. This is wired into the ignition circuit at the ignition barrel. This kills power to the alternator, coil, fuel solenoid and in your case the fuel pump.
Engine wont even start unless the switch is pulled out.
I would normally switch the negative side of the circuit to eliminate surges and sparking .
Means you cant kill the engine fast when required and isolate the battery for safety etc.
My electric fan keept blowing 20A fuses so im upgrading to 30A
LR110 ..... LJ50 project 
Chris.
Chris.
Re: eleckky question
UBZ wrote:Im running an Battery isolator switch(Spark free Marine Sealed) on the positive side of the battery. Switch is located next to battery in the back. 120A Circuit breaker inline after the switch. (from Jaycar)
This is for isolating the battery only. For safety, works, etc
Mines a marine two pole switch on the earth (neg) side to chassis, same reasons basically.
Kill switch is a big red push button type switch that is mounted on the dash. This is wired into the ignition circuit at the ignition barrel. This kills power to the alternator, coil, fuel solenoid and in your case the fuel pump.
That's the plan for later but mine will be a toggle switch until I get a free/cheap stop button.
Engine wont even start unless the switch is pulled out.
I would normally switch the negative side of the circuit to eliminate surges and sparking .
Could you explain this a little more? is that the neg side of the ign circuit (the earth in my case) or am I too simplistic? And what do you mean by sparking?
Means you cant kill the engine fast when required and isolate the battery for safety etc.
My electric fan kept blowing 20A fuses so im upgrading to 30A
I'll try some 25's and get some 30's for later on. When does yours blow? On startup or during running? Hope the relay will handle the amps now, better check it too for suitability.
Heath
Re: eleckky question
This is to the best of my understanding.
Sorry if i describe this in too simple a terms. But its the easiest way i can think of to put across at complex idea.
Think of electricity like water.
You switch on a Positive connection the voltage (water) floods up the cable from the battery (pump).
The current (pressure) is dependent on the draw required from the device/s on the wire (pipe)
When it reaches a device it hammers to a stop or through a restriction.(just like water hammer in pipes)
This surge of current can cause wiring to burn out, in line devices to burn out, sparking can also occur inside connectors or basically anywhere you have a join or connection. The more devices wanting power the higher the surge.
Positive switching is hard on an electrical system.
With negative switching the power is all ready at the device and just needs a route to earth.
When the connection is made to earth the current is consumed by the device and the voltage just needs to ground out to the battery.
ie the turbine has taken all the pressure (current) out of the pipe. and the water just needs to run away.
There is no hammer or surge of power in a negative switched system.
Negative switching allows you to run switches a long way away from the battery without having to contend with volt drop over distance and you only have to run one wire for a switch as you can ground it locally.
The problem with a negative switch is that if you get a fault to ground before your switch the circuit will become live even though your switch is off.
My electric fan is wired this way. The relay is on the negative side of the circuit. This way the relay never has to handle high current. I still have a fuse on the positive side near the battery.
Hope this helps and that i haven't just confused you more.
I was blowing fuses on the fan every time I turned off the head light or spots and the fan got all the current it wanted.
Was working on trial and error for the fuse rating as I have no idea at all my fans ratings
Sorry if i describe this in too simple a terms. But its the easiest way i can think of to put across at complex idea.
Think of electricity like water.
You switch on a Positive connection the voltage (water) floods up the cable from the battery (pump).
The current (pressure) is dependent on the draw required from the device/s on the wire (pipe)
When it reaches a device it hammers to a stop or through a restriction.(just like water hammer in pipes)
This surge of current can cause wiring to burn out, in line devices to burn out, sparking can also occur inside connectors or basically anywhere you have a join or connection. The more devices wanting power the higher the surge.
Positive switching is hard on an electrical system.
With negative switching the power is all ready at the device and just needs a route to earth.
When the connection is made to earth the current is consumed by the device and the voltage just needs to ground out to the battery.
ie the turbine has taken all the pressure (current) out of the pipe. and the water just needs to run away.
There is no hammer or surge of power in a negative switched system.
Negative switching allows you to run switches a long way away from the battery without having to contend with volt drop over distance and you only have to run one wire for a switch as you can ground it locally.
The problem with a negative switch is that if you get a fault to ground before your switch the circuit will become live even though your switch is off.
My electric fan is wired this way. The relay is on the negative side of the circuit. This way the relay never has to handle high current. I still have a fuse on the positive side near the battery.
Hope this helps and that i haven't just confused you more.
I was blowing fuses on the fan every time I turned off the head light or spots and the fan got all the current it wanted.
Was working on trial and error for the fuse rating as I have no idea at all my fans ratings
LR110 ..... LJ50 project
Chris.
Chris.
Re: eleckky question
You don't ever want to disconnect the battery whilst the vehicle is running as the alternator detects the battery voltage level to determine how much charge it should output.
Isolating the battery will mean the alternator thinks the battery is dead flat and will therefore attempt to output at full noise which will eventually kill it.
A simple kill switch will mean the vehicle can't be restarted but won't stop it from running, as described you need to stop the alternator output and interrupt the battery as well.
Matt.
Isolating the battery will mean the alternator thinks the battery is dead flat and will therefore attempt to output at full noise which will eventually kill it.
A simple kill switch will mean the vehicle can't be restarted but won't stop it from running, as described you need to stop the alternator output and interrupt the battery as well.
Matt.