Fuse Problem

While this problem isn't seen as much as it used to be its still worth while knowing about. The out come is the possibility of permanently damaged or intermittently malfunctioning equipment. 

We had trouble with glass fuses in those inline fuse holders, the ones we had trouble with are the glass body fuse with chrome end caps that has the fuse wire material soldered in place. The solder on the end caps of the fuse when used in some inline fuse holders that also use a soldered area or spring for connection can cause high resistance between the contacts very quickly. The lead/tin in solder appears to oxidize reasonably quickly. The flow on problem is that it can cause the failure of the attached equipment due to it not being supplied with the correct voltage and current.

Glass body fuse, the one on the left has the fuse material soldered in place, the fuse carrier on the right is preferred

To check, open the fuse holder, if it does not grip the fuse around the end cap but relies on pressure on the ends, be aware to make sure the fuse holder contact area does not have soldered ends, the ends should be smooth and shiny, preferably with the fuse size stamped on.

Another problem we have experienced is that the small contact area and lack of spring pressure of some fuse holders can cause excessive heat and failure of the fuse holder. A lot of the cigarette lighter type appliance plugs are being made to a price and while they are stamped as being capable of sustaining 10 amp however they come with a 2 amp fuse. In all our experiences using the plug at higher current (>2 Amps) by replacing the fuse with a larger fuse will ultimately see the quick failure of the plug due to internal contact failure, poor contact gives rise to resistance and under load this resistance causes excessive heat, the higher the load the more heat generated, the body of the plug then starts to melt and before you know it, you smell smoke at about the same time the appliance connected via the plug fails. Unfortunately the only real way around this is to purchase the high end, brand name plugs.

In the photo the end cap that is not soldered can be identified by the fuse size stamp on the cap end.