What Size Fuse?

[henryj]

I bought a 3 way splitter for the cig lighter on my truck so I can run all my electronic toys, like GPS, iPOD and TPMS, while traveling. I made the mistake of plugging my air compressor into the splitter instead of direct and promptly blew the 2 A in line fuse in the splitter. The air compressor has an 8 A fuse. The truck's cig lighter circuit has a 15 A fuse.

The 2 A in the splitter seems a bit paltry. I didn't even have a chance yet to see whether it will supply enough power at 2 A for my 3 toys. Can I safely bump that up a couple of amps? I have no need to run the compressor off the splitter--I just wasn't thinking--I'll plug the compressor in direct from now on.

Henry

[Steve Collins]

Henry,

I'd be cautious about upping the amperage of the fuse too much. If the body of that splitter is all plastic and the wire is fairly small (18 awg or smaller), then it probably is designed to carry minimal current which explains the 2 amp fuse.

I have a splitter here that has one of the three outlets made of all metal and ceramic materials. And it has 14 awg wire and a heavy duty male plug. That suggests that the splitter can safely handle higher current loads, possibly even a lighter, up to the rating of the vehicles outlet. Another one here is all plastic and has 16 awg wire. I don't run anything too powerful through that one but it works just fine.

My truck has a 20 amp auxilary outlet which could easily fry a light duty splitter if not properly fused.

Test the splitter with a 2 amp fuse and your favorite accessories. If the fuse holds up, you may be good to go as is. If the devices tend to blow the fuse from time to time but not often, you are probably right on the edge. Going to 3 amp is likely not a problem, but I would be leary of going any further.

Hope this helps.

[henryj]

Steve, thanks for the, as always, good advice. This episode has helped me expand my limited electrical knowledge. I never really thought much about what I was buying--I liked the style. When I went back to the store to get a new fuse I looked at some of the other styles more closely and there is indeed a difference in the weight of the cord and the heaviest one had a 5A fuse. The lesson here is buyer beware and know the draw of accessories before buying a splitter.

With a little digging I found that the iPOD and TPMS draw about 200mA each and the GPS just under 500mA. So these fairly typical electronic toys with their LCD screens do need only minimal current and obviously that's what my splitter was designed for. The 2A fuse should be fine and I did have all 3 running at the same time earlier this afternoon. I doubt if any splitter would power an air compressor and I should be able to remember to plug it in direct. If I don't, I had to buy a 5 pack of fuses...

Henry