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LED Bars and wiring


Old 04-17-2017, 10:26 AM
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Default LED Bars and wiring

Hi guys,
I want to install some LED lighting on my truck.
At this point i want a 28" bar in the center of my Back Rack and one 7" Flood LED bar on each side.
2 7" Bars 36WATT each = 72Watts
28" Bar 180Watts
What size wires do i use to feed them.

21amps looks like what they are going to pull at maybe 25' so it says 6 gauge wire. sounds big no.
and what about the relay? will it handle that?
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Old 04-17-2017, 12:04 PM
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does seem high....
normal 30 amp bosch relay and 14 ga is all I used to wire these... no problems yet...
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Old 04-17-2017, 12:44 PM
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I think the Wattage is what they are equal to not what the draw is so the formula puts amperage at 21amps = 6 gauge wire. I can't find the actual bar amp draw.
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Old 04-17-2017, 11:05 PM
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Make sure you have as shout a ground wire as possible and that it is good and clean between the connector and panel.
As far as the size, you probably won't be anywhere near 25'. I did mine and I don't think it was even 10'.
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Old 04-19-2017, 02:38 AM
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Quality LED manufacturers will always include in the nomenclature what the amp draw of each unit is expected to be. You will find that the actual power draw in amps (amps = watts divided by volts) will be about 1/10 of the wattage output. Cheaper lighting units will be a crap-shoot, and of course, perform poorly (compared to quality units).

So, as an example, if you were to use a Rigid light, and the wattage on a 28" bar was 154 watts, then 154w * 13.8v = 11.16 amps. On a Rigid, for those 11 amps of current you get 12,880 raw lumens/3800 lux.

For this, you can use 16ga on the 28" and 18ga on each of the 7" (6"?). Use 1 30amp Bosch relay for each switch you plan to use. Oh, and don't think more leds on a cheap unit will get you more light. Look on you tube for guys who have posted the real world differences between eBay lights and quality brand lights. The results will surprise you. Save your pennies for the good stuff.
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