wire loads

[Dezertpilot]

How much amperage can a 10 guage wire contain before the wire melts? I had a problem this weekend at the MORE race but I think it was actually the 20 amp switch that failed thus causing the wire to start to melt. The switch is for my dual elec. fans for my radiator. I am not running a relay cuz me and my friend do not like relays. I know some people say that you are supposed to run one but we are not. I am running 10 guage wire from the fans/fuse block to the switch. I replaced the 20 amp switch with a 50 amp one so that should solve it but I am wondering if their is now too much load on the wire. Sorry if my terms are not that correct I am not really great with electrical. Thanx.

[FlyHiFlyLo7]

How much amperage can a 10 guage wire contain before the wire melts? I had a problem this weekend at the MORE race but I think it was actually the 20 amp switch that failed thus causing the wire to start to melt. The switch is for my dual elec. fans for my radiator. I am not running a relay cuz me and my friend do not like relays. I know some people say that you are supposed to run one but we are not. I am running 10 guage wire from the fans/fuse block to the switch. I replaced the 20 amp switch with a 50 amp one so that should solve it but I am wondering if their is now too much load on the wire. Sorry if my terms are not that correct I am not really great with electrical. Thanx.


30amps.... but if you have a direct short to ground yer screeewed.

[FlyHiFlyLo7]

By the way...you and your friend might not like relays but they do isolate your circuits. Thus, preventing what happened to your switch. Your lucky you didn’t toast any other stuff.

[JaxMotorsports]

Relays are the way to go on fans, most switches won't carry the load of a fan. 10 gauge is good as long as the run is not over 15 feet. Here is a chart that tells you all you need to know about wire size. Good Luck Jack

http://www.rbeelectronics.com/wtable.htm

[Dezertpilot]

Thanx guys. Yeah if I do have a direct short to ground I guess I will be screwed. I am going to rewire the fans in the near future just need an open weekend to take out and rewire some of the wires in my 4runner. I am running the 50 amp switch so I do think I will be fine for a long time and the run isnt over 15 feet. I REALLY want to redo alot of the wiring but I am kinda electrically challenged but did just successfully attempt a dual battery setup with my buddy Matt's help. So what exactly does a relay do. How are they wired up? I have my dual Lightforce 240 Blitz's on a relay and that was my first wiring job not the prettiest but it still works!

[Scott_F]

In the simplest terms, a relay uses a small amount of current to switch a large amount of current. The small current goes through a coil, which creates a magnetic field. The field pulls on contacts to switch the high current.

[Dezertpilot]

ok thank u.

[McClintock]

http://www.blueink.com/CLASS/physcom1/relay.jpg


Simple relay info:
www.r1200gs.info/ howto/relay.html

[FABRICATOR]

Anyone here use solid state relays??

[ntsqd]

I've got a couple, but have yet to use them. I like the no moving parts idea for the dirt. Those I have are not rated for DC current, but their AC rating is such that I don't forsee a problem.

On that wire gauge vs. current load vs. distance chart, note that if you have a ground wire that it too figures into the length.

[Superfab]

When I wire race cars I use Klixon circuit breaker switches on everything. They give excellent circuit protection and let you know if you have a short. They operate like a regular toggle switch. They are not cheap..about 80.00 ea but neither is the cost of a race. As for figuring wire load ranges Ace hardware sells a book "Pocket Ref by Thomas J. Glover "that has a chart of maxumum wire length (Feet) for car wiring. It tells you all you need to know.

[Jack]

The wire and switch should be able to handle it depending on the fan. Just go 25% over the max draw. The wire size is fine. What the problem most likely is, is the conection at the switch. Is it just a crimp on then slide on to spade? These are notoriuos for melting. You must solder the wre drirectly to the switch termanal if you want it to last in the dust.

[Dezertpilot]

The new switch I am using (50 amp) has the connections as a screw on type. The wire gets crimped on to the round eye and that gets screwed on to the switch. How will this work?

[OldStroppeTeam]

The new switch I am using (50 amp) has the connections as a screw on type. The wire gets crimped on to the round eye and that gets screwed on to the switch. How will this work?


I prefer to solder the ends on the wire, crimps don't always stay crimped....

[DJDIRTWORKS]

30amps.... but if you have a direct short to ground yer screeewed.
__________________
A direct short should not be a problem-you should just blow a fuse or trip a circuit breaker. If you havent protected your wiring with fuses or breakers, your are asking for big trouble. Electrical fires caused by shorts(rubbing, chafing, vibration all make this a very possible occurance)can quickly turn into whole vehicle fires. An unprotected wire shorted out will flow a huge amount of current until it melts in half. I don't remember the exact temp. , but copper melts at something like 1100 deg. F. I seen too many vehicle fires due to this problem. One other thing, where you place your overcurrent protection in the circuit is critical as well- put it in the wrong place and and it's the same as not having one.
As far as what caused your problem, like some one else said, a loose connection will cause that. Also, a cheaper or under-rated switch will also melt. The switch or loose connection can not handle the heat caused by the current flowing through it( current flow, as well as resistance, induces heat) and as a result begins to distort. When this distortion becomes severe enough, an arc will occur, an arc is hot enough to melt metal, and now the distortion becomes worse, causing a bigger gap for the arc to jump, causing more resistance, causing more heat... it just turns into a runaway reaction until either the components melt "open", breaking the circuit, or until everything burns up...
Superfab is right , use breakers- they protect your gear and usually give you a visual indication of what circuit has failed. If you cant afford breakers, use fuses. They are now making fuses with blown-fuse indicator lights built right into them that are pretty handy. AutoZone I know carries them.

[Dezertpilot]

So what about an inline fuse holder with a 30 amp fuse? I think Ill run that this weekend when I get some time. I am planning on doing some rewiring this weekend and I will take your guys comments into consideration. So where could I purchase one of these circuit breaker systems at? What are the specs on these? Do they handle multiple accessories? Any one have any links? Id like to check these out....thanx.

[Dezertpilot]

Oh and where can I get these Klixon circuit breaker at? Any piks? Oh and I like the blown fuse light idea seems pretty handy.

[frankh]

Never understood why people think a relay fixes a currant problem. You need to switch a circuit that has a 20 amp draw. You can either use a manual switch or a relay. No matter what you have a set of contacts that need to handle 20 amps. It does not matter where the contact are at. The relay is made mainly for two reasons are. 1- To remote the contact- this is so you can limit the run of large wire. Not a problem on a race car. 2 - To isolate a person from a high voltage. Again not a problem for a race car. The big thing to remember is a fuse or circuit breaker as close to the battery as possible.

[Superfab]

You can get Klixon breakers at http://www.aircraftspruce.com/cathome.php . They are series 7270-1. They come in 3,5,10,15,20,30,35 amp ratings. Check the amperage rating of your fans. If they are 22 amp run a 30 amp breaker on each. This way if one fan burns up it doesn't take out the other. A 10 ga wire is good for about15 feet @30 amps. Run at least an 8 ga wire to feed the breakers (You can jumper them together with a 10 ga wire). Nice part is if the breaker pops the switch goes to the off pos which is easy to see. No guessing and if the fan smokes it wint kill the wires. Most fuse holders don't like the surge of the fan turning on and they can smoke the fuse contacts. I don't know what brand or model fans you have but the most common mistake is running too much stuff off one circuit and overloading it. Most good fans take at least 15 amps on up to run each! Most switches you buy will burn up over time due to arcing of the contacts especially with near capacity loads. If you look at most top class one or tt they use breaker switches cause they don't fail. I hate being parked with electrical problems so i get a little anal about using good stuff. Besides, we never geet enough seat time for $ spent anyways.

[Kbach66]

I prefer to solder the ends on the wire, crimps don't always stay crimped....

I've never been a fan of soldering wires....too much vibration equals a broken wire. I've never wired any offroad vehicles, only on-road race cars and motorcycles, so I'm sure the vibration amounts/frequency is pretty different.

I guess if you're gonna solder it, make sure it's secured well to the chassis as close to the solder/connector joint as possible.

[Jack]

If your solder is breaking from vibration then you did not solder it at the right temp. If it is breaking from wieght load then you did not sicure the wires properly. And if this is the case you will have even more poblems with a slide on or srew termanal.

[JaxMotorsports]

I agree

If you use the right terminals and the right crimper, crimp is better then solder for vibration resistance. If you look at the old aircraft connectors in a junk yard they were all soldered on but if you look at the new Canon and Deutsch connectors the use crimp on pins, granted the crimper for those is around $350 bucks but we are getting off the point. If you are wiring a "Race Car" and using toggle switch style breaker or correctly rated Aircraft grade toggle switch and push to reset circuit breaker then that's great don't use a relay, but If you are Wiring a play car and you are getting your stuff at Pep Boys Use a relay and a circuit breaker because no switch sold in a chain auto parts store is going handle the load of a electric fan for more then a few cycles.
There are a lot of different ideas on how to do wiring, and sometimes there is more then one right answer. I remember there was another thread like this and PCIScott chimed in with some good info on relays, but I could not find it, if you see this Scott please add you two cents. Thanks Jack

[Dezertpilot]

Well I am using a k4 switch from Kartek rated at 50 amps with 10 guage wire and an inline 30 amp fuse. I am pretty sure it will work untill I play with the wiring this weekend. I think I might throw in a relay for safe measures. Keep the info coming you guys sure know alot more than I do and I am really soaking this up. Oh can I solder on the wire to the connector that is usually crimp on? Or how about me crimping on the wire to the connectore then soldering over it? Thanx for all the replys....

[Dezertpilot]

Oh and where can I get some of these Canon/Deutch connectors? These are the connectors that the wire attaches to and then to the switch/relay correct? And while we are on the topic of electrical can anyone reccomend(sp?) a good electrical warehouse in Corona or Riverside area. I used to know of a couple in Rancho Cucamonga but I dont want to drive that far if necessary.

[John_Bitting]

All this stuff is foreign to me.. That is why I am gonna hire a professional wire guy to wire up the Project Blazer. I will post a whole write up and pics of it so people can see whats all involved if you want to tackle it yourself..

[Dezertpilot]

John the best way to learn about wiring is to dive into it. My buddy Phorensic is a wiring pro so I just listen to him and he helps me big time. The more I get involved and see what is going on the more I learn which is good. I think if you can be with your wire guy when he does the wiring and ask questions if he will be patient enough. If you are in the middle of Mex and have an electrical problem at least you know what it could be or have an idea. The more I learn about electrical the funner it is to me. This is one area that I would love to be profecient at. I was looking at the connectors from Cannon, Deutch and some of the other connectors and I am really curious as to what application they are used in.

[5racer]

why have two fans on one switch your asking for trouble 1 fan 1 switch because if one fan motor starts going bad the amps will jump way up there and blow breakers or melt wires .but if you only have one swicth then it also kills the fan with a good motor .and you can chase this problem for ever because alot of times the fan motors run great tell they get hot if there on one switch how would you tell what fan could be your problem



2 fans 2 switchs only way .

[John_Bitting]

I will watch and learn for sure, but I think people specialize in their respected fields for a reason. Kinda like why you go to the doctors when you are sick verse listening to your buddy diagnose you. For me its peice of mind paying a professional whom specializes in wiring to do the job right the first time. In the long run it pays off, If I tried to do it myself and shorted out a GPS, radio, or computer or had a short and fire etc.. I would have wished I paid someone the first time and not had to replace everything I already bought. To each his own. I have nothing but respect for the person that tackles it themselves. I am just not that person.

[5racer]

btw spruce aircraft has switches with built in breakers right in the switch less wire and one less componentkinda priceie but worth it them come in sizes 5amp to 50amp

[Dezertpilot]

Steve are u saying that these switches with the built in breakers would eliminate a relay? So I can have one of these breakers installed and then when I blow the fuse I can reset them while I am driving? Id like to run a high amperage switch. I think there is an Aircraft Spruce here in Corona by the airport I believe. Do u know what they cost? Oh and John I wasn't even saying to tackle the elec. job your self but to maybe watch, ask Q's and learn if possible. There is no way Id be able to compitently complete a task like the one your Blazer is going to reciev in the future. Oh and Steve I am not sure if I can run each fan off of their own switch I believe they might have come pre-wired to run on one switch. I'll check I am not positive on that. I just dont really like relays all that much just another part to fail in my eyes. I am really leaning towards the switch with the breaker built right into it. Oh and why all of a sudden would the breaker get tripped? A surge in power caused from something?

[Dezertpilot]

Ok so Superfab so you are saying to run a resettable breaker switch for each fan and run say a 30 amp breaker for each fan so if one fan blows it does not take out the other one. Like I said they might come from the factory pre-wired for one switch but I will look tommorrow. Now can I get away from using no relays with the set up I am talking about? More now, then run at least a 25 amp switch or bigger for each fan. Ill run 8 guage from the fans to the resettable circuit breakers then jumper them together with a 10 guage wire. Now what is the point of doing this? I am slowly learning about electrical so please excuse some of my comments I do not know all that much. Then what size wire do I run from the circuit breaker(s) to my main on/off fan switches? If somebody could quickly put up a diagram this would help tremendously. I was looking at the Klixon switches from Aircraft Spruce the 7270-1 and I like that I can now get rid of the inline fuse holder and run a set of these Klixon resettable circuit breakers in place. I am now only running a single inline fuse rated at 30 amps I had a 25 amp fuse but it blew so I then put in the 30 amp and it has not blown at all yet.

[Superfab]

Sent you a pm with ph# and explanation.

[Ramsey_ElWardani]

2 fans 2 switchs only way .I have to agree; why have the current draw of two fans if conditions only require one like on a cool day.

[mgobaja]

Allows you to also only use the current you need for that one device, like wiring 1 or 2 lights per switch. Then if you loose a light it doesnt take out the whole light bar.

[5racer]

pre-run yes aircrafft spruce is in corona and they have a free cataloge right at the front door .and the switchs are automatic reset .and i personaly dont run relays .i also use silver coated wire for the fact that you can run 2 times the amps with half the size the wire gauge but you will faint when you see price of wire inless this is a race car just use heavy gauge copper wire .

[14802]

With larger amp draw item's, like radiator fan's, tranny coolers,and light rack's. Make sure you use a good 'WEATERPROOF" connector(soldered-crimped-plug) as long as it fit's tight and vibaration will not affect it, you should be good.
Also make sure the wire size, and style is correct for your application.(primary wire. vs less stranded wire crap.) Resetable breaker's can save your butt(who want's to change a fuse @ any speed). Relay's work and they work awesome if sized properly,with the correct sized wiring.......Sealed switches is a must

[14802]

pre-run yes aircrafft spruce is in corona and they have a free cataloge right at the front door .and the switchs are automatic reset .and i personaly dont run relays .i also use silver coated wire for the fact that you can run 2 times the amps with half the size the wire gauge but you will faint when you see price of wire inless this is a race car just use heavy gauge copper wire .
True siver coated wire is "somewhat" fragile. If it is a tin-copper wire (silver color) it is a high temp(insulation)wire, with a fiber outer sleeve and a inner silcone sleeve. But none the less an expensive and good grade wire....

[Dezertpilot]

automatically resetting breakers...awesome. This is the 7270-1 model? Didnt have time this weekend but I will be doing this soon and doing it right.

[14802]

try these http://www.nteinc.com/relay_web/R58.html

[Dezertpilot]

Nice...another brand to think about. Do you know the price on these?

[Superfab]

The 7270-1 are not auto-resetting. When they break they go to the off position. You can allways put a small light in the circuit to show when things are on. The silver coated wire is teflon covered , has a slightly higher load ratinge but a much higher temp.range. The coating is thinner and more abrasion resistant than the automotive but costs lots more. It's also more corosion resistant and slightly lighter so thats why its used in aircraft.

[Dezertpilot]

I do not think I would/should use the better wire Ill just stick to the reg. stuff I dont want to spend all that much money. Who makes the auto reset breakers? I like the sound of those.......

[14802]

Personally I've never seen them.(You might be referring to a thermal over-load style more of a motor with restrictive load??) But think,if you were going along in the dez and for whatever reason you shorted a cooler fan wire, that (auto-reset) would be resetting it (sparks and all) till it either killed your battery, welded it to ground and starts a fire..Nice to have a visual button(on the breaker) pop up and you need to inspect the situation further..

[Dezertpilot]

14802 you are totally right I think Ill just stick to the Klixon 7270-1 style with either the toggle switch style or the push button type. How would I go about wiring a light into the system to tell me if the circuit breaker is on or off?

[Superfab]

Just hook one end of the light to the switched side (fan side) of the breaker and the other wire to ground. Use the toggle type breaker. The push button is not designed to be used as a switch.

[Dezertpilot]

So superfab are u saying that I can now use the 7270-1 series Klixon switches as my actuall fan switch or are they run in conjunction with the on/off fan switch? Like I said I am electrically retarded but I am learning.....lol.

[5racer]

h-p books has a good book about wirering very helpfull for begienners.

[Dezertpilot]

Steve where can I purchase this book at?

[Superfab]

Use them as the switches. The less stuff in a circuit, the less stuff to fail!

[5racer]

Steve where can I purchase this book at?
il get addy for you tonite and post it but you mite try like a pep boys our your local auto parts store

[Dezertpilot]

Thanx Steve...the more and more I look at this whole wiring scenario the more I seem to understand it...well sorta,haha.