Fuses Blowing? Why Going Bigger is NOT the Solution

We were recently on a boat that kept blowing fuses to one of its electronic devices. What is the standard mistake made in this situation? Trying some bigger fuses! There are two reasons we use fuses. One is to protect the wire feeding a device (in case of a short or too much current); the other is to protect the device/appliance at the end of the wire. Even if you have a huge wire feeding a device, you need to use a size of fuse based on the device requirements.

In this recent case we encountered where the owner had installed bigger fuses, his feeder wire could handle the extra current and was still fine, but inside the device got melted pretty significantly when he put bigger fuses in to try and make it work. When multiple correct fuse replacements blow (sometimes one blow one can happen by fluke), there is a problem somewhere that needs proper attention. Putting in bigger fuses is not going to solve the problem or make anything better. It's only going to make the situation worse (and present possible fire hazards). In this case there was obviously a problem with the device itself, which was causing the fuses to blow. The only solution would be to remove and replace the device (or fix it if possible). By putting in bigger fuses you take what was a manufacturer's problem with that device and make it much worse. This might void the warranty of the device, and will certainly make it harder to fix.