Coax Connectors and Amps

JZH

JZH

International Bodger
Joined
Feb 26, 2006
Messages
429
Location
London, UK/So.Cal.,USA
It's been a while since I've upgraded any of my heated gear, which mainly consists of vintage Gerbings and Warm n Safe controllers sporting the old SAE/trailer connectors. I've decided to tiptoe into the 21st Century and convert to the now-standard "coax" connectors, but I am concerned about the power handling capabilities of this connector. The connector is a DC power connector measuring 2.5mm x 5.5mm. Most such connectors I have found seem to be rated by their manufacturers at no more than 5A, yet the dual wired Heat-Troller I've got came with a 15A fuse. With a dual controller with only one connector plugged in, wouldn't that potentially mean that the fuse would not blow until all 15A had gone through that one connector?

Another way of looking at this, however, is that with thousands of these connectors being used on a daily basis, I would have heard if there had been any problems associated with "overloading" these connectors by now...

I am assuming that the moulded connectors being used by manufacturers of heated clothing are not "special" high current versions not available anywhere else--the days of proprietary electrical manufacture are mostly long gone--virtually everything is available on Alibaba! In my current installation I would like to use a waterproof (IPX7) coax power socket (made by GTC), but it, too, is only rated for 5A. Perhaps I am worrying too much... :(

Cheers,
 
JZH said:
Perhaps I am worrying too much...
Click to expand...

Sounds like it in this case too...

I am generally and electric safety crazy type of person. But in this case I just have to bow to "well it works" and go with the crowd.
The one thing I can say is that we are talking low voltage, so no chance of getting shockled and the fuse will blow if anything melts and dead shorts.
Actually most of the controller have short circuit protection built in, so if the output connectors dead short they are shut-off. Now if your input is a 2.5mm plug, be sure it is fused.

This is cold weather gear, so the environment is helping keep the connection cool? Does that help?
 
When I was looking into updating the connectors on my heated here a read a couple of articles that stated that there are higher amperage versions of the coaxial plugs. It was stated that this person had tried the lower amperage version and they got quite warm and failed. I don't remember where I read this but will look for it again.
 
I know someone that used some pre-made cords (not knowing that the wires that were in the range of 22 gauge). The plugs didn't get hot, but the wires sure did. Didn;t melt but you could feel the warmth.

Make sure the pre-made plugs you buy have 16 or 18ga wire attached.

I bought some male/female extension cords and planned to cut them in half. I was thinking they were all pre-molded and would provide better strain relief (and be more durable) then what I could solder at home. The male ends were, the female ends were just standard jacks soldered on.
 
One option is a convertor from SAE to Coax if safety is a concern. I've got several of those and they work just fine. Or you could cut of the SAE piece on the cord and the adapter then solder them together. Or buy a glove harness that already has the coax connectors and cut them off and solder the wires together.
 
Uncle Phil said:
One option is a convertor from SAE to Coax if safety is a concern.
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I'm confused Uncle, if you convert the SAE to coax, you still have the coax inline and passing power. The only thing you did is add in another connection and a little voltage drop.

Now cutting off the coax and soldering in the SAE I can see being safer.
But even then, what are the spec ratings on SAE?
 
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T_C said:
I'm confused Uncle, if you convert the SAE to coax, you still have the coax inline and passing power. The only thing you did is add in another connection and a little voltage drop.

Now cutting off the coax and soldering in the SAE I can see being safer.
But even then, what are the spec ratings on SAE?
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The adapters just keep you from cutting and soldering. It maybe a presumption on my part, but I figure Powerlet would use the 'proper' bits and pieces on their adapters. I've found their stuff pretty expensive but very reliable. If you get a Gerbing glove harness, the coax ends on them and the wire appear to be 'heavier' than the ones that come wired into the jacket liner. When my jacket liner glove connectors broke, I opened up the jacket and soldered in the heavier glove harness leads.
 
I was going to get a Y-harness and solder in the connectors to convert my old Gerbing liner, but bought a used micro-wire liner with the correct connectors instead. Gave the old liner to my son. I wish now that I would have done the conversation on the old liner.

If you run your heated gear for short periods of time then the cheaper connectors might work. I don't want a connection to fail though halfway through a 10 hour day, so I buy whichever OEM coaxial adapters I can find on sale and cut the ends off.
 
mlheck said:
Here is a discussion on the ADVRider forum that talks about this same subject.
http://www.advrider.com/forums/showthread.php?t=399252
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Thanks, all, and mlheck for that link.

(I used the Switchcraft L712AS/761KS15 "Sealed Power Jacks" in a previous project, but I was not very impressed with the sealing mechanism. They claim IP68, but the rain cap is a little rubber plug that is easily knocked out--allowing water to flow straight into the housing.)

So, 5A it is. I'm probably going to basically ignore the power ratings and just use the largest gauge wire I can... :eek::

Ciao,
 
Don't worry about it. Use the coaxes if you want. You are only going to be running about 9 amps with a W&S jacket liner on continuous, maximum heat. A little less for a Gerbing. I have never had either of my liners on maximum heat, and I have ridden at 19 degrees F. for over 120 miles.

You can run up to 10' of 18 ga wire at 12 volts with 9 amps safely. Personally, I would go with 16ga just to have that extra margin of safety. I prefer SAE connectors because they are easy to find, they fit my stuff and have never had any issues with them.
 
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My impression is that the typical coax connectors do a good enough job...and are very convenient to use. but SAE type connectors are capable of passing much more power. add too many "adapters" and any semblance of reliability goes out the window
 
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