Fuse blows randomly

Dx7388 · Oct 14, 2019

Hello, thank you. I am DYI. Our daughter has home built in the 60s with fused service panel. One fuse has started blowing ; when a new fuse is put in, it will not blow right away, it can go for hours sometimes without blowing. It is a 20- amp fuse/circuit. On the circuit is a microwave and several regular outlets. The microwave has not been in use when the fuse blows. There is nothing excessive on the circuit and just normal use. Nothing out of the ordinary is being used when the fuse blows. I have checked that there are no foreign objects in any of the outlets. I have read that the fuse SOCKET can sometimes be defective, after decades of use. Do u think that is a possibility? The fuse socket contact looks a little pitted to me but I don't know if enough to be a problem. I cleaned it with a toothbrush and electrical cleaner (sparingly) and let it dry well before reinserting fuse. It didn't seem to help, the fuse still blew after a few hours. The fuse blows randomly (no set time or period of time). The panel is dry, I see no evidence of water intrusion. The fuse is Bussman SL 20 amp. I appreciate any help you can give me!

telectrix · Oct 14, 2019

you may have damaged cable on the circuit, could be as it warms up due to use a poor piece of insulation is breached thus blowing the fuse. my advice is to call a local electrician

Lucien Nunes · Oct 14, 2019

A fault with the fuse socket can cause the circuit to go dead or the fuse contacts to become scorched, but not to blow the fuse itself. As per Tel, you probably have a damaged cable causing a short circuit either at an outlet or anywhere along its length, if the fuse blows with all appliances unplugged from that circuit.

Megawatt · Oct 14, 2019

Dx7388 said:
Hello, thank you. I am DYI. Our daughter has home built in the 60s with fused service panel. One fuse has started blowing ; when a new fuse is put in, it will not blow right away, it can go for hours sometimes without blowing. It is a 20- amp fuse/circuit. On the circuit is a microwave and several regular outlets. The microwave has not been in use when the fuse blows. There is nothing excessive on the circuit and just normal use. Nothing out of the ordinary is being used when the fuse blows. I have checked that there are no foreign objects in any of the outlets. I have read that the fuse SOCKET can sometimes be defective, after decades of use. Do u think that is a possibility? The fuse socket contact looks a little pitted to me but I don't know if enough to be a problem. I cleaned it with a toothbrush and electrical cleaner (sparingly) and let it dry well before reinserting fuse. It didn't seem to help, the fuse still blew after a few hours. The fuse blows randomly (no set time or period of time). The panel is dry, I see no evidence of water intrusion. The fuse is Bussman SL 20 amp. I appreciate any help you can give me!

DC7388 it sounds like the socket that you screw the fuse in has lost its ability to conduct electricity. As far as getting it fixed the NEC only allows replacing fuses and thats it. My suggestion to you is hire a licensed electrician to replace that panel. I betting the fuse is warm if not hot. Good luck