Master Disconnect Switch

etjeep

etjeep

New Member
Joined
Apr 20, 2005
Location
Cary, NC
I picked up a Cole-Hersee master disconnect switch recently. Its P/N 2484-16, http://www.colehersee.com/catalog_top/index.htm and is rated for 175A continuous / 800A intermittent.

I was originally planning to mount it under the hood for the convenience of flipping a switch to disconnect my battery when not using the jeep instead of disconnecting the battery leads. I did a little web surfing and found this switch is used for “emergency disconnect”….so this got me thinking.

Would it be worthwhile to mount in the cab within reach? I have 2 12V ignition powered circuits (one for the fuel injection and one for everything else), plus the starter lead. Under normal circumstances, the ignition key can de-energize. In a rollover scenario,….. potential shorted wires, gas leaks….it would pay to have this switch conveniently located. I can find room to mount in the cab.

My question, for those who often find themselves rubber side up, is this worthwhile or is it overkill. I have a lot of $ and time invested in my rig and the last thing I want is a fire. What do you use to kill your power in a rollover. BTW I have a separate winch battery.
 
I always say a master disconnect within reach is worthwhile. A must for any of my contraptions I drive. It's those freak things that worry me like a hot wire rubbing somewhere you can't get to. Like even a turn signal wire rubbing after a little rock rash.
I've had to jerk an amplifier out of my brothers car going down the road one night when a faulty wire ignited. He'd either recked or bailed while his car burnt to the ground if I wasn't with him. Still have flashbacks to this day with a radio going.
Has anyone seen a dash pad, a seat or even enamel paint on a hot hood go up? Master Disconnect within reach all the way for me!
 
^^^ X2 I would not want to open the hood everytime I shut down but I'm lazy like that
 
My plan was to run a pull disconnect on the buggy. Since I won't be using any kind of keyed start it'd be nice to have a mildly hidden but still in reach pull that if I roll over I can grab or if I want to walk about from the buggy and feal a need to secure it.

The main thing I thought about when I rolled bigwaylons TJ was the ignition. I thought about that and keeping my head low during the long period (seemed like it) it took to go over. So I'm pretty sure once to come to a stop, I'll remember to do.
 
ERIC
I plan on putting on some bigger quick connects like the ones that are used on the winchs. Plan is to use them for the battery and tie the winch in with one so the jumpers and welder will plug to it without needing to lift the hood.
Pull one main and no drain on the Battery when not driving.
Use maybe 3 total...
 
I run one within reach for the reasons you have mentioned. I haven't run into a situation where it would be a bad thing to have.
 
Thanks all. I like the good input so far. I figured I'd ask here to see what ya'll have done.

I have to look into the locations some more....I could either bring in all the power leads to a location under the dash or mount it on the tranny tunnel just under the seat. If I mount it on the tunnel, only the rotarty toggle needs to be in the cab and the terminations can be under the jeep. I guess there pros and cons to each location.

Jon, I think the quick connects would be good for a battery saver. I was thinking along the lines of a rollover sceanrio...your belted in, upside down with the motor running.....I think I want to kill it fast.
 
Jon,
Another thing. I just bolted on a 140Amp alternator and I have a dual battery setup with an isolator.
 
I wouldn't put it under the seat. One thing I did notice while upside down hanging by the seatbelt is there is now way I could reach anything that low. In fact, I had trouble reaching the seat belt latch while holding myself from hitting the ground when it let go :shaking:
 
Now thats good advice! I had'nt really thought much about that. I guess I'll come up with something under the dash then. Thanks.
 
Someone had better address the issues with running very large gauge wires (needed to put a disconnect in the cab) thru the firewall and around all the other sharpe metallic junk under your dash! IOW, if you think a shorted amp makes a mess... standby!

This a major reason why the most folks don't run amp gauges... that huge wire carrying the full load of your battery shorting against something... Superman ain't fast enough to keep your entire rig from melting to the ground!
 
I spent some quality time with the jeep and came up with a better plan tonight. Caver mentioned an issue that I have work around in my new plan.
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First, I plan to keep all the heavy gauge wires in the engine bay. The Cole-Hersee switch will live under the hood. This will be mainly for the convenience factor so I have one switch to flip when storing/working on the jeep.
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Second, I am still going to run an in-cab kill switch, but I am changing the design to use a combination of a solenoid and relay. I think it will be just as effective as wiring the Cole-Hersee into the cab and will be a lot simpler to wire. Then I can dash mount switches without having the bulky heavy gauge conductors to worry about.....-in the cab. My Mamouth starter has an integral solenoid, so I had previously eliminated the stock Ford style solenoid in my setup. I plan to bring back the Ford style solenoid with this new design and mount it to the fender, near the stock location. I plan to wire this solenoid to a dash mounted kill switch. I already have a toggle switch but will probably try to find a different type of switch. At this stage, I am hoping the intermittant duty starter solenoid will be adequate since I already have a few laying around. If not I will upgrade it to a continuous duty solenoid.
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Third, I'm just going to run a relay, probly a 30A (have to study this a little more, might go to 40A) to power my ignition and other circuits. I'll wire it in parrallel with my solenoid switch so I can incorporate a hide-a-switch for theft protection. I like the idea of integrating some theft protection with a hidden switch and having a more conspicuous .....and easy to reach... kill switch.
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Even a lazy dog gets a bone now and again....This is a plus, when I added the fuel injection and bypassed the ameter, it left me with an extra 10 ga. wire wired through my main wiring harness connector to the fuse panel. I coiled it up and tucked it away thinking I might be able to use it for something......there's my bone.
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Sorry for the long post and thanks for all the great ideas guys. This is going to come together nicely. I guess the only other thing I need to do is wire my CB into the main kill switch circuit for constant power so I don't have to reset the channel every time I employ the theft protection.

Edit: I found out the intermittant duty solenoid will not cut it due to the heat generated at the coil. I'll just use a continuous duty solenoid instead.
 
MR. GADGET said:
ERIC
I plan on putting on some bigger quick connects like the ones that are used on the winchs. Plan is to use them for the battery and tie the winch in with one so the jumpers and welder will plug to it without needing to lift the hood.
Pull one main and no drain on the Battery when not driving.
Use maybe 3 total...
Click to expand...

Jon I was browsing my Waytek catalog this AM and saw an "Anderson Connector"...Is that what you have? Also are you running a RW or something else?
 
etjeep said:
Jon I was browsing my Waytek catalog this AM and saw an "Anderson Connector"...Is that what you have? Also are you running a RW or something else?
Click to expand...
The look like the Warn or ready welder ones just two times the size and take a lot more amps hit up John on CNC for them he use them on the toyota forkers that he works on and they are big juice lots of amps. going to put a "T" handle on the front to pull if needed that anyone can pull if needed anytime to kill power on the trail. It will also help for charge and jumping or anything else...
 
Eric, yes, Anderson connectors are what you are looking for, Waytek is cheaper to buy them for personal use. Del City is another source for these as well, and their site seems to be easier to use.

I can get them from work as well, ( same place as mentioned above fork lift tech, as I work with Jon )

The connectors come in three sizes, 50amp, 175amp and 350 amp, the 350 amp connectors are about $10 per side ( 2 needed to make a connection)

DO NOT solder the lugs onto your cable, use a crimptool, solder adds resistance which causes heat, can and will fail if used heavily.

If you are going to be riding with someone else who may have these connectors, color co-ordinate, so you can help each other out if need be. LIKE colors fit together, mis matches do not.

Also, as for mounting a kill switch, mount it remotely and use a cable or push/pull rod to actuate.

We install these on some customers lift trucks as emergency kills, there is no "safe" place in the dash so they are mounted remotely. ( usually mounted on explosion proof " EE" rated lifts)
 
MR. GADGET said:
The look like the Warn or ready welder ones just two times the size and take a lot more amps hit up John on CNC for them he use them on the toyota forkers that he works on and they are big juice lots of amps. going to put a "T" handle on the front to pull if needed that anyone can pull if needed anytime to kill power on the trail. It will also help for charge and jumping or anything else...
Click to expand...
Jon, I see. Thats a good idea, especially if you get knocked out. Someone can just yank the cables without entering your truck. Are'nt those suckers gonna through sparks when you disconnect? I surfed some and saw the mechanical solenoids with a t-handle. I think its good to have some quick disconnects nevertheless.
 
Blkvoodoo said:
Eric, yes, Anderson connectors are what you are looking for, Waytek is cheaper to buy them for personal use. Del City is another source for these as well, and their site seems to be easier to use.

I can get them from work as well, ( same place as mentioned above fork lift tech, as I work with Jon )

The connectors come in three sizes, 50amp, 175amp and 350 amp, the 350 amp connectors are about $10 per side ( 2 needed to make a connection)

DO NOT solder the lugs onto your cable, use a crimptool, solder adds resistance which causes heat, can and will fail if used heavily.

If you are going to be riding with someone else who may have these connectors, color co-ordinate, so you can help each other out if need be. LIKE colors fit together, mis matches do not.

Also, as for mounting a kill switch, mount it remotely and use a cable or push/pull rod to actuate.

We install these on some customers lift trucks as emergency kills, there is no "safe" place in the dash so they are mounted remotely. ( usually mounted on explosion proof " EE" rated lifts)
Click to expand...
Kevin,
Thanks thats good to know. Thats a little cheaper than the solenoid & relay route I was planning. I am not all that keen on the Painless rape your ass products. I would rather figure out what to do and fab it myself.

I was initially thinking I could use something like that for a winch disconnect, but I bought a Ramsey solenoid/remote switch ($50 from Northern) for my new Ramsey winch. The only problem I see is its a Patriot Profile 12000 and kicks out 465 amps at full load, so I may fry those connectors. Thats a separate issue though.

I am thinking I can get out from under this kill switch rampage for somewhere around $100 if I find the right deals and wire everthing myself.

My kill switch will be mounted remotely. On the one hand a mechanical actuated switch is simpler but I don't understand the infatuation especially if you can not get to it. Maybe I can integrate some t-handle into my underhood switch. Sorry if I rambled a bit in this and my original post.
 
Are you setting up to kill the positive or the ground? On all the heavy equipment we build at leeboy we kill the ground side. Some of our newer model machines are tier 3 engines & this has no effect on the computer systems. This would keep any sparks from flying.
 
etjeep said:
Are'nt those suckers gonna through sparks when you disconnect?
Click to expand...


Yes, they will spark a little when pulled, but they will ARC like crazy when re-connected if there is a load present.

I run into this alot when solinoids and contactors stick on the electric forklifts, these running anywhere from 24 - 48 volts and up to 300 amps at times. Yes, it gets exciting sometimes. ( pun intended)
 
Jeff B said:
Are you setting up to kill the positive or the ground? On all the heavy equipment we build at leeboy we kill the ground side. Some of our newer model machines are tier 3 engines & this has no effect on the computer systems. This would keep any sparks from flying.
Click to expand...

Jeff,
I see your point. I read that a lot of the master disconnects are set up to isolate the ground for the very reason you stated. I don't claim to have all the answers...I believe I should wire the master disconnect this way but it could go either way. I need to develop a schematic since I work better with pictures.

If I used the Anderson connectors would I not have to burry the quick connects and expose a t-handle that was wired to the ground for someone to pull? If I had two anderson connectors exposed, someone would likely disconnect both....trying to do good.....and generate a spark in the process. Just a thought.
 
Eric,
The Ford starter relay will not work for what you want to do. It can not handle the constant current. I tried this a long time ago. I was using the ford type realy to turn on and off some very bright offroad lights. I had to keep replacing it all the time. I would not recomend that you use it
 
Blkvoodoo said:
Yes, they will spark a little when pulled, but they will ARC like crazy when re-connected if there is a load present.
I run into this alot when solinoids and contactors stick on the electric forklifts, these running anywhere from 24 - 48 volts and up to 300 amps at times. Yes, it gets exciting sometimes. ( pun intended)
Click to expand...

Kevin,
Thats what I thought. I am really talking about two separate and distinct items here, not to get confused.....the first is a master disconnect switch. It would be mounted under hood. It is a mechanical switch with exposed leads. I would flip this switch when working on the jeep or when I have the jeep in storage. I ought to try and wire it to the ground circuit as Jeff suggested.

The second system was a kill switch using a relay for the ignition circuits and a continuous duty solenoid for the starter circuit. I am not an expert by any means, but in my simple mind you have an internal coil pulling in a magnetic core to energize/de-energize a circuit. The switching is internal. My guess is that since you are making the circuit internal to the device it should be okay to put wire these devices in the power circuit and not worry about external sparking unless you plan to remove the leads.....which you obviously have done.:huggy:
 
Ridgerunner said:
Eric,
The Ford starter relay will not work for what you want to do. It can not handle the constant current. I tried this a long time ago. I was using the ford type realy to turn on and off some very bright offroad lights. I had to keep replacing it all the time. I would not recomend that you use it
Click to expand...
Carl,
Thanks, I figured that out. Was not thinking about that late last night. I researched it a little this AM and figured I would use a continuous duty solenoid.

I just need to figure out the amperage draw on my Mamouth starter so I can get one with the correct amp rating.

An 85 amp continous duty solenoid is $30 ish and the 200 amp jobs are around $60-$70, based on my limited browsing so far.
 
FYI- I got a continuous duty solenoid rated for some serious amps from a place in raleigh for $40 or $50 a few years ago. I don't remember the amps off hand but I know it was plenty to keep up with my 140 amp alternator and I haven't fried it. I use it to combine the two batteries on my truck. I got it from the RV place near the corner of New Bern and New Hope Rd.
 
dawson444 said:
FYI- I got a continuous duty solenoid rated for some serious amps from a place in raleigh for $40 or $50 a few years ago. I don't remember the amps off hand but I know it was plenty to keep up with my 140 amp alternator and I haven't fried it. I use it to combine the two batteries on my truck. I got it from the RV place near the corner of New Bern and New Hope Rd.
Click to expand...

Dawson,
Thanks. I can't think of any RV places over there right now. I will keep my eyes open though. I was not even thinking of doing this two weeks ago. I'm going to call it progress.
 
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