|03-13-2013 08:18 PM|
|03-04-2013 07:34 PM|
Awww, are you guys done already? I really didn't want to get into this, but my experiences with relays must be a bit different from bc3_Jeep's. I have been installing remote start systems, alarms, and plenty of other items that require the use of relays (often with "interposing" relay setups) in vehicles for over 7 years professionally; all the shops that I worked in offered a lifetime workmanship warranty. I have yet to have a customer return with an issue relating to a relay (or "interposing" relay setup) that I installed - I credit this to my experience and extensive electrical knowledge... KISS really has nothing to do with it. If a wiring circuit is properly designed and executed, there is no issue with using one relay or even ten if needed. While all efforts should be made to keep the system as simple as possible, reliability also needs to be considered.
I think that using a single relay to power all of the circuits is reducing the reliability of the OP's system. Sure two 100w lights only draw 16.6666 amps of current, but add in another set, maybe even two more sets, and you are doubling or even tripling that number. So the OP gets a 60 amp relay to power it all - how hot do you think that relay is going to get with 60 amps of current running through it?
I would wire it all up so the actual toggle switches are just low current triggers. Then run each individual set of lights off it's own relay triggered from the toggle switch - standard 40 amp relays would be more than safe here. Then, for the "master" switch, you can use it's low current output to trigger all of the relays at once - just throw a couple 3 amp diodes to isolate the triggers. Seems pretty simple to me...
|03-04-2013 04:11 PM|
Set - noun
a number of things of the same kind that belong or are used together, or
a group: complete collection
Set implies 2... or more...
Reading is our friend, too, because now we know it is 200W, or a common driving light wattage, not 100. L... wait for it.... MFAO!
|03-04-2013 02:01 PM|
I will also adjourn after this comment....... 100W/12V is LESS THAN 10 Amps. (as cited in my original design post, not the one where I predicted (correctly I might add) that relay mongerers would attack my design)...... + 25% WOULD EQUAL LESS THAN 12.5 amps..........not 20+ amps......this circuit, fused at 12.5 Amps with a 15 AMP (non drab????) switch would do just fine. If you are worried about longevity, use the 20 Amp version for a....wait for it.... wait for it..... wait for it.......60+% margin of safety.....as opposed to just a 20+% margin of safety with the 15 Amp switch. MATH is our friend....
According to my illustrious co-contributor, who....and I quote as to not belittle him, "I assure you I understand electrical principals and theory, particularly lower voltage systems like found in vehicles, despite your repeated attempts of belittlement. " Has abundantly shown he is incorrect in his statement AND understanding of low voltage as applies to that found in vehicles, unless my calculator is lying to me.
Case rested.......proven... and unfortunatley for some......UNCONTESTABLE (unless my calculator IS lying to me)....... thank you for your continued support in the continuing, unrelenting, endeavors of the UNRELAYABLES.....
|03-04-2013 01:19 PM|
Never heard of OFC wire? It is a measurable standard of copper purity for wiring, something I do not trust chinese recycled materials to achieve. Ever wonder why chinese metal breaks? Low purification of recycled goods. Now OFC is usually reserved for audio and electronic uses, but If you are suggesting 10A down 18ga or 20A down 16ga, I would make damn sure that silver tinned Oxygen Free Copper wiring, which is also shielded from Oxygen during manufacture, was used as it has less resistance or loss than just about any other wire - short of silver or gold. Of course, using 1 size larger regular copper wire is much easier, and what all us "complicated mongerers" do. For simplicity and all.
I am not interested in the original design of a failed componant; if I have the ability to refine a product to a better state, I will. Even at the cost of an overwhelmingly complex switch board full of "destined to fail" relays.
A 40A relay IS better than a 20A switch, glad ya didn't want to argue that. Of course with the OPs intention of using common rocker switches, he is left with a large variety of 15 and 20A switches at reasonable prices. Buying 40A switches that are drab instead of a neat switch and relay for less $ overall and having a 4$ fail point that is abundantly available is simpler, but makes a lot less sense. So I suppose there are some apples in there afterall. Needless to say with your recommendations any 100w set would need a switch higher than 20A to allow 25% overage, as the fuse protecting the circuit would be 25A. Well, unless you would have the switch totally fail before the circuit is protected, anyway.
I assure you I understand electrical principals and theory, particularly lower voltage systems like found in vehicles, despite your repeated attempts of belittlement.
I didn't need to wear pants today, but I sure am more comfortable than in shorts. Also don't need a jeep, scooters and bicycles move folks around just fine, but that doesn't make it a better way. Sure, more can break on a jeep than a bike, but the cost-benefit proves worth it.
Do old headlight switches fail from amperage? Yup.
Is 120 common circuitry running a 40w light on 12ga wire anything like vehicle wiring? Nope, apples and oranges.
Why do fans run on relays? So a temp sensor (or switch, electrically speaking) doesn't carry amperage... same with your horn.
I guess you are right... we should ditch intermittent wipers, rip out horn relays and rewire them, and return to lead based paint and asbestos insulation while we are at it. After all, it sure is a simple way.
Driving around in 2nd gear at 50mph works, too, but is horribly effecient. Of course, 2 gears are simpler than 5. Must be why we have all these 6 spds now.
And I just love how you say not to be scared of a relay - unless it is "not needed"... if you need one, they work fine, but if not then it will come and get you! Lmfao.
OP, sorry for the childish bickering. I believe I have made all the impact possible, so I adjurn. As there are obviously conflicting views, feel free to do a bit more research elsewhere and see what ideas exist. I promise you will find hundreds of threads about people running relays without incident.
|03-04-2013 09:40 AM|
Let me preface this with....I do not own a SINGLE spool of wire that says "quality oxygen shielded" nor have I ever seen one in 37 years of doing this kind of stuff.
I am supposing.......Jeep buys their wire from Crutchfields....... just supposing here.....and they are NOT going with the lowest bidder on every SINGLE piece of wire in that whole friggin' vehicle........ let me know, Jeep accounting dude, if you monitor this stuff.
Putting a granite countertop in an outhouse DOES NOT make it bathroom.
If the dielectric strength of your insulation is rated... it is rated.....does not matter the manufacturer or origins. Granted... some stuff from China can be a bit shady, but I am not prepared to condemn an entire nation's wire making ability here. Such hyperbole serves no purpose in the end.
A VERY valid point was made a 40 Amp relay WILL outlast a 20 Amp switch......... just like a 12,000 pound winch will pull TWICE as much as a 6,000 pound winch. Apples to oranges.
I agree...... do not be afraid of relays (my design uses one)......and.... as I have stated emphatically over 100s of times... use them when NEEDED...... not just because you do not understand simple electrical concepts like Kirkoff's Law.... or Ohm's Law.
Be very afraid, however, when told to use something NOT NEEDED.
Is there a relay between your light switch in your house and the light in the ceiling?????? I doubt it......
Was there a relay on headlight setups in vehicles BEFORE computers..... NOPE.....
Did wipers have relays BEFORE intermittents????? Nope..... not usually
These things ALL worked without relays for decades (some still do)....... and will continue to do so..... despite the misguided efforts of people who champion relays JUST BECAUSE......
When you are making something you WANT to be reliable......KISS.... Keep it Simple Stupid.....
|03-03-2013 04:40 PM|
I have yet to see a control switch with low amperage go bad from overheating. I have seen many 15 and 20 amp switches fail used under those load ratings, but above 10A. I find the notion that a 20A toggle is more robust than a 40A relay quite comical. Is this because SOMEHOW the principals of effeciency change? And what is it that makes a toggle so much more capable than a coil switch? Again, Lmao.
If you're telling me Advance Auto Parts AutoCraft wire is as capable as say Crutchfields selection, in regards to power wire, for amperage applications, I will continue to lmao. Cheap chinese wire is not as good as quality wire. But again, go ahead and trust 18ga to run 110w, lol.
Enough of that sillyness...
OP, don't be scared of relays. When used right they really pose no greater risk than a switch. Switches controlling .15A @12V designed to run 20@12 will last until it physically breaks from being flipped so many times, not because of contacts. So you aren't adding some hidden danger, you are transferring the point of failure from the switch to the relay, which is just a switch anyway. Relays are cheap and readily available, and add very little complexity to a system. They also provide other benefits typically, like more effecient power delivery.
|03-03-2013 03:24 PM|
Need I say more???????
1 switch + 1 relay = TWO things to go wrong.....
2 switches + 2 relays = FOUR things to go wrong....
You do the math.......with little effort you are DOUBLING the potential problem sources.
As far as switches cooking with time and current, HOGWASH............a properly sized switch will last as long as any properly sized relay contact.
and I DO NOT HAVE A CLUE what backfeeding current through a switch is all about... been doing this almost 40 years now and THAT is a new one on me....is the path of least resistance somehow modified here?
An interposing relay is an interposing relay does not matter the system conversion..
AND.... as a matter of order only...... the correlation between audio wiring and power wiring is irrelevant due to RMS loading and PEAK power issues with audio signals which do not occur with standard lighting circuits.
|03-03-2013 11:11 AM|
Not to step on toes, but
I would be very cautious backfeeding 17A through the contact of a 20A switch. It will get hot... it would be better to splice into the wire further down from the switch contact (towards the load) so energizing the relay will not run the amperage through the contact when it isn't nessesary to, or make sure to have a higher amperage switch (most cool aftermarket rockers are 20A).
I would be very cautious following that chart. As the author admits, 20A is a great deal to run through 16ga. I would bump a column to add a margin of reality. Directly beneath the chart he adds: "The values here for 12V usage are not yet certified to be correct/valid/safe - they are my ballpark figures based on what I believe to be true based on what I have learned. Consult other sources of information for your specific application for more details." CYA, for sure, but none-the-less I would be careful trusting that on parts store wire (I own spools with much lower manufacturer recommendations for amperage). Quality oxygen sheilded wiring is usually a bit more, like what you would find in highend stereo shop. If you want to run (2) 55W lights on 18ga, be my guest, but it will be cooking the wire (and moreso the connections) every time it is on. Mine have 14ga, and are wonderfully bright.
Interposing relays typically use one voltage to control another or one relay to control another... not really what we are after here. We want to use a low amperage switch to control a high amperage switch, which also can allow a more direct feed of power to the load. That way our switch doesn't overheat after years of use, nor is there a requirement to run larger wires into the cab. Relays are mechanical switches, when used simply they aren't as prone to failure as some may imply. I suppose using 1 switch to control another does complicate matters a wee bit, but then again running headlight amperage through YJ factory switches fries them, so obviously some switches just cannot handle amperage long term, even when engineers design them for that purpose.
Besides all that, would ya rather plug in a 4$ relay or replace a 20$ custom switch?
No, you don't need them for safety. Fuses do that.
"Misguided" rant over.
|03-03-2013 12:38 AM|
|cctriesch||How hard is it to hit 4 switches and turn everything on? It might have cool factor but seriously. click, click, click, click... Or 3 hours of wiring everything.|
|03-03-2013 12:17 AM|
|Crazyndn||Once I can afford the Rigid setup I want, this post will be the guide for me. I have the general concept down and do know the amp/wire/fuse madness that's involved(knowing that you have to have a little over your goal amperage for the wires, like you said, not the equipment the wire's running to.) Learned that the hard way from stereos and not using a fuse block... nearly burned down my car from that shit. So I hopped in a book and started to unfuck myself. Been burn free since.|
|03-02-2013 10:08 AM|
|03-02-2013 07:22 AM|
^^^^This is a good design, but not sure it was what the OP was asking. If it is what he wanted, I WAY over designed......... LOL
I read it as wanting to turn them all on IN SPITE of the positions of the other switches.
|03-01-2013 08:32 PM|
|03-01-2013 08:32 PM|
|Peepers||I had 3 pairs of driving lights, and 2 flood lights on individual switches. What I did was have a master switch that powered the other 5 switches. If all 5 switches are on, the master switch turns everything on or off.|
|03-01-2013 08:27 PM|
KISS (Keep it Simple Stupid)....... if it CAN break.... it WILL BREAK.....
Got it from the US NAVY......a long time ago....
the ONLY reason newer vehicles HAVE relays is because the control is now coming from a TTL level device and it NEEDS an interposing relay to be able to work. It is NOT a protective measure as people have professed, nor NECESSARY as others have decried... it is all about PPD......PI$$ POOR DESIGN... adding devices that are NOT needed because you do not truly understand WHAT you are doing.....
|03-01-2013 07:12 PM|
|03-01-2013 01:14 PM|
First....... find out how many AMPS each set of lights will draw....... Watts/12V (unless you are running a weird voltage) will get you close enough. 55W bulb will draw "about" 5 amps (actually 4.583), two 55W will draw 10, etc. Once you know THIS number, you can size your fuse and your wire.
Fuses should be sized at AMPS times 1.25 (roughly, go with a common size that is VERY CLOSE, common is GOOD... odd size is hard to find when you need it) and are meant to protect WIRES, not equipment.
Reference AMP/wire gauge to determine what size wire you should be using. 16 gauge STRANDED (not solid) will handle MOST automotive lighting situations, but yours may be different.
Wire Capacity Chart
when you have all of those AMP numbers, find switches that will handle each set of lights and find A RELAY (will need as many Normally Open (NO) contacts as you have individual light sets (if you cannot find one with as many contacts as circuits you have, let me know and I will expound on how to "make more") that will handle the TOTAL SUM of all your AMPS (this will be turned on by your MASTER ON switch).
Wire each INDIVIDUALLY switched set of lights +12V (fused at AMPS X 1.25) on one side of switch and Power to lights on the other side. Keep all of the wires the same on EACH individual switch (use colored wires if it helps).
Ground the light sets to the frame/chassis/superstructure close to the mounting points as long as you are using metal mounting systems. If not, run similar size wires back to the nearest metal point that is connected to frame/chassis. Apply dielectric grease to these attachment points if you have it (will prevent galvanic corrosion and loss of condctivity over time)
Test each set of lights INDIVIDUALLY to ensure they are working.
NOW.... using the last switch, wire one side of it to +12V and the OTHER side to +coil on relay, -coil needs to go to GROUND. EACH POWER OUT side of the previous switches should go to a (NO) set of contacts on your relay. The OTHER side of the NO contacts should go to +12V (this should be fused at TOTAL AMPS x 1.25).
When you turn ON last switch, it will energize relay, which will route +12V to all of the light sets at the same time. if a set is ALREADY on..... they will remain on... if a set is OFF, they will come on.
|02-28-2013 03:31 PM|
|bc3_Jeep||This is quite simple given the right switches, but.... as I do not believe in interposing relays, I will let the relay mongerers misguide you to their delight and see if it works out for you.... if not... let me know.|
|02-28-2013 02:31 PM|
Multiple Lights/Multiple Switches question
I'm looking into adding some fog/driving lights to my 2006 TJ, but have a different setup in mind. I'd like to run fog lights, driving lights on windshield, and possibly additional backup lights (maybe even trail lights underneath). That being said, I'd like to run one switch for each set but then have an override switch that turns them all on at the same time. Any ideas on if/how this can be accomplished safely?