Light bar wiring harness
- Thread starter judoant
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Bumbo
New member
Do you have any more information, perhaps a link to the bar itself?
I seriously doubt your lightbar actually uses that much juice. 540 watts at 12 volts is 45 amps of current. That’s a ton of power for a light bar, even a good one.
I recommend you try and measure the actual current draw. Just as an example, this is a “120 watt” light bar, which uses no more than 50 watts in operation.
12.30 x 4.01 = 49.32 watts
Generally speaking, I have found a 12 AWG wiring harness with a 30 amp relay to be more than adequate for almost all lighting solutions I have seen. Unless you are running something really special here, I would not be too concerned. That said, none of this means anything until you actually measure your load.
I seriously doubt your lightbar actually uses that much juice. 540 watts at 12 volts is 45 amps of current. That’s a ton of power for a light bar, even a good one.
I recommend you try and measure the actual current draw. Just as an example, this is a “120 watt” light bar, which uses no more than 50 watts in operation.
12.30 x 4.01 = 49.32 watts
Generally speaking, I have found a 12 AWG wiring harness with a 30 amp relay to be more than adequate for almost all lighting solutions I have seen. Unless you are running something really special here, I would not be too concerned. That said, none of this means anything until you actually measure your load.
Here is the bar.
https://www.amazon.com/Nilight-18025C-50000LM-Driving-Warranty/dp/B07X9LB9G9
Here is the harness they just recommended
https://www.amazon.com/Nilight-Wiring-Harness-Waterproof-Warranty/dp/B074GYNJ85
https://www.amazon.com/Nilight-18025C-50000LM-Driving-Warranty/dp/B07X9LB9G9
Here is the harness they just recommended
https://www.amazon.com/Nilight-Wiring-Harness-Waterproof-Warranty/dp/B074GYNJ85
I don't know if its posted wrong on Amazon but that thing is 30V.......
Not gonna work unless you got more to your set up.
*Edit
Well I scrolled down more and it says 9V to 30V. Amazing how Amazon has more product information than their own damn website.
12AWG should be good assuming you putting it upfront.
ampacity.jpg Photo by skylark462 | Photobucket
Not gonna work unless you got more to your set up.
*Edit
Well I scrolled down more and it says 9V to 30V. Amazing how Amazon has more product information than their own damn website.
12AWG should be good assuming you putting it upfront.
ampacity.jpg Photo by skylark462 | Photobucket
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Bumbo
New member
Most lighting I have come across works on 12v and 24v systems, so 30v would be the top end of a 24v systems input voltage.
While I too use those ampacity charts, that one is a bit aggressive in its selections… 3 feet of 12 AWG has a 8% voltage drop with 100A going through it. That conductor would be smoking hot. I try and keep my voltage drop to no more than 2% to 3% ideally… 5% max.
I generally limit my 12 AWG conducts to no more than 30-40 amps depending on the application. Even if the conductor can handle it, the contact resistance of other connectors, like the spades connecting to the relay, would soon become the limiting factor and main generator of heat. Insulation temp ratings also play a very large role, meaning use quality wire.
The website specs don’t tell us much of anything. I would venture to GUESS, than the actual consumed power is 50% of what they advertise, meaning you might see a 20-25 amp load, making a 12 AWG wiring harness sufficient. Again, without measuring the actual consumption this is all speculation / best guess.
While I too use those ampacity charts, that one is a bit aggressive in its selections… 3 feet of 12 AWG has a 8% voltage drop with 100A going through it. That conductor would be smoking hot. I try and keep my voltage drop to no more than 2% to 3% ideally… 5% max.
I generally limit my 12 AWG conducts to no more than 30-40 amps depending on the application. Even if the conductor can handle it, the contact resistance of other connectors, like the spades connecting to the relay, would soon become the limiting factor and main generator of heat. Insulation temp ratings also play a very large role, meaning use quality wire.
The website specs don’t tell us much of anything. I would venture to GUESS, than the actual consumed power is 50% of what they advertise, meaning you might see a 20-25 amp load, making a 12 AWG wiring harness sufficient. Again, without measuring the actual consumption this is all speculation / best guess.
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