Tower lights / using relays?

[Razzman]

I know many of you have tower lights so I'm wondering if they use relays as they do for autos? I'm getting ready to help a bud wire some up to his Sanger. Do they series wire all the lights together to larger gauge wire for the +,- and ground?

[spharis]

I don't know if they use them or not, but I would without a doubt. I would wire the lights straight to my deep cycle battery, with a fuse or breaker, through a relay.....then I would wire the relay trigger to a panel switch.

[Razzman]

in essence a normal auto install without taping the lighting system of a car. I wonder if a heavier gauge wire could handle the load of four lights to the relay without cooking it? I've checked a couple of online install instructions from different tower mfgrs and they only show three wires from the bank of lights to the power source, so that's how they got to be doing it.

[spharis]

Just pick your wire gauge to the current that will be going through it.....also check the amp rating on the relay. I think you will be fine. 12V are usually 60-90 amps....more than your altenator can put out. As far as wire goes, 16AWG will handle 25amps with no sweat.

Amps = Watts/Volts

So if you have 4 50W bulbs.....50/12= 4.2Amps......

16 gauge wire, and a common auto relay will do you fine!

[gman]

I may be wrong but 16awg for 25 amps is a little small. should be more like no. 10awg copper. Check the ratings of the wires.

[spharis]

http://www.powerstream.com/Wire_Size.htm

AWG Diam amps
16 0.0508 22

says 22 but it is not giving the 30% measurement. Usually in electroinics you pad your parts 30-50% for fluctuation and spikes.

i guess a proper chart would be to use this one
http://www.the12volt.com/info/recwirsz.asp

regardless you would have to have 4 50 watt lights to get close to metling 16 gauge wire. You will probably have a 10A cb, on some low wattage leds lamps, or similar I hope.

[Razzman]

Actually we are putting four 55w Hella 1502's on the tower.

[spharis]

4*55 = 220Watts

220/12V= 18.4 amps

Go with a 30% buffer so use a minimum of 14gauge....actually walmart sells 12gauge speaker wire in 50 ft rolls.....would fit the bill.