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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Gary LaBombard on December 14, 2007, 04:43:30 AM

Title: Recommend wire size for LED lights??
Post by: Gary LaBombard on December 14, 2007, 04:43:30 AM
Hello Everyone,
I am near my part of the conversion to install my new marker lights or at least locate the wiring etc. for them at this time.  I am enclosing a photo of the lights held onto the side of my bus temporarily by Velcro.  There is (6) LED lights I am mounting as you can see in the photo's.  I have decided to mount them directly over the center of the wheel wheel wells and over the center of all three bay doors.  When seen for real they look real good centered over these areas and not measured directly center to center dimension wise spread over the length of the bus.  The difference of measurements between them as I plan to mount them is only a few inches and cannot be seen with the naked eye, or at least mine anyhow.    By equally spacing them from front to back the lights fall off center of the doors and wheel wells and they just do not look symmetrical.  I guess I am one of them guys!!

Anyhow, my original reason for this post is to get feed back not knowing about new wiring of new fixtures for sure I wanted to get feed back from the more experienced converters using LED lights.  What wire size is recommended by you in the THHN wire for wiring up 6 lights on each side of the bus.  Most of my new replaced wiring on the entire bus is done in (12GA) and this is just way to heavy to work with where I need to and this will be a trip to do as I cannot wire form the inside of the bus.  She is already converted inside.

I am hoping #16 GA. will be sufficient but my mind says use #14 which is a lot easier to use than #12. These lights have 16 LED's each in them.   

Thanks ahead of time and also thanks for the information you all gave me concerning the locating of these lights some time ago.  Oh, by the way, I am lowering the lights 2 inches down from this photo view, it was easier to mount them like this and connect up the wiring as I did for these views.  The height is below that allowed by DOT. 

I just thought of another question concerning the locating of lights on Eagles in particular.  I noticed on some Eagles that I payed attention to that the front side (marker & Directional) lights are located behind the front wheel well on the right side and in front of the front wheel well on the left side??  Is this true of all Eagles and what on earth is this reasoning, anyone know??
Gary
Title: Re: Recommend wire size for LED lights??
Post by: Ncbob on December 14, 2007, 05:11:51 AM
Hi Gary,

Can't answer most of your questions about Eagle lighting patterns and such but since LED's require so little current to operate them I can't see why 16Ga shouldn't do the trick.

Looks like we won't be seeing the Eagle at Arcadia this year...but it's looking like you might make it with her next year, right?

I found a misplaced set of transfer screws (1/4-20) that should have been in the tool box...will hold them 'til I see you.

Bob
Title: Re: Recommend wire size for LED lights??
Post by: JackConrad on December 14, 2007, 05:13:18 AM
Gary,
 16 gauge should be fine. LEDS draw in the milliamp range.  Someone else can probably give you an exact milliamp draw per light, but it should be well under the capacity of 16 gauge wire.  
   I have no idea why Eagle installed the lights asymmetrically.  Jack
Title: Re: Recommend wire size for LED lights??
Post by: tomhamrick on December 14, 2007, 06:03:58 AM
Hi Gary, One thing to keep in mind with the positioning of your lights is what you will see in your mirrors at night. The original round markers behind the front wheel well on the side of my model 10 have a piece of chrome covering the front half of the light so that it is visible from the side and the rear but does not blind you at night. It is surprising how bright these lights are and without the chrome cover I could not see behind me at night.
Tom Hamrick
Title: Re: Recommend wire size for LED lights??
Post by: gumpy on December 14, 2007, 06:07:12 AM
Jack is correct in that the lights will draw in the tens of milliamps range. It depends on how they are connected inside. One LED will typically draw 20 millamps or so, but can be connected in series, up to 5 or 6, and will still only draw 20 millamps, so 16 could conceivably be connected in 4 strings of 4 leds, for a total of 80 millamps. Blah Blah Blah...

So, to find out how much current they draw, connect one of them to a battery with an amp meter hooked in series and set on 10 amp setting. A small hand held multimeter works well for this.

As for wiring, 18 ga would be sufficient. 16 ga is overkill. However, THHN should probably not be used here as it's intended for household wiring. Instead, get some automotive primary wiring. You can get large rolls at Home Depot, or NAPA will have packets of 50-100 ft.

craig
Title: Re: Recommend wire size for LED lights??
Post by: Ednj on December 14, 2007, 06:26:20 AM
These might be useful to someone in the future with placement

http://www.grote.com/tech/fmvss/bus_chart.html



http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/393.11.htm



http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/571.108.htm
Title: Re: Recommend wire size for LED lights??
Post by: Gary LaBombard on December 14, 2007, 06:51:51 AM
Tommy,
Thanks for the tip.  I connected up the lights to view this fact and noticed that the lights I bought do not refelect very much at all sideways looking down the side of the bus, but man if you stand directly in front of the side of the bus facing these guys, they are bright.  So I doubt the side view will interfere with vision in my mirrors.  The LED lights are about 3/8k" thick, not much room for side glade of them when turned on.

Gumpy,
I choose the THHN wire as I thought this wire has a more heavy duty outer casing which is plastic I believe.  This would make pulling this wire around metal tubing a little easier and I would be more assured that the casing on the wire would not get damaged causing a short in time from vibration etc.  I am sure open to suggestions and assurances of my thoughts on this as I said this is beyond what I have done so far.  I saw some primary today infact and was not impressed with the outer casing but I will use what the more experienced have suggested.

Thanks again,
Gary
Title: Re: Recommend wire size for LED lights??
Post by: Jerry Liebler on December 14, 2007, 07:16:54 AM
Gary,
   Whatever size you choose just be sure the circuit breaker is properly sized.  10 amp for #16, 15 amp for #14, 20 amp for #12.  The marker light circuit has so many separate lights on it, if they are all LED's 16 should be fine but if some may be ordinary bulbs you may want to up the capacity.
Regards
Jerry 4107 1120 
Title: Re: Recommend wire size for LED lights??
Post by: Kristinsgrandpa on December 14, 2007, 09:08:57 AM
Gary, the automotive primary wire will be cheaper than THHN because it is cheaper wire. The outer jacket on THHN is nylon.

The THHN  is as follows: The first two letters TH is for thermoplastic the third letter (H) is for the heat rated, and the last (N) denotes nylon outer jacket.

If it were THWN then the third letter, W means it is more suitable for wet locations.

(I hope I got that right as my school was from 1968 thru 1972. and I've slept since then)

Probably the best wire is boat wire, it is finer strand and tinned.

Jerry brought up a good point which a lot of people ignore. And to make another point on fusing, the fuse/breaker can be undersized. Like a 5 or 10 amp breaker on # 14 wire even though it is good for 15 amps.

Ed.
Title: Re: Recommend wire size for LED lights??
Post by: muddog16 on December 15, 2007, 05:53:38 AM
Gary, lots of good accurate information everyone gave you in this post!

Pat