ever seen a blown cut-out fuse?

Yes, we saw one a couple of months ago, caused by a builder not understanding that an RCD, despite being labelled '40A, 30mA' is does NOT contain overcurrent protection, basically leaving the shower protected by the 60 amp BS1361 in the service head.


Also being a builder, he hadn't torqued the terminals.  The result was inevitable... the terminal slowly charred, went higher resistance, got hotter still.. and over the course of 2 days, burned itself clear, whereupon it pressed the now bare live load wire into the earth sleeving.


Apparently the bang was loud enough to be heard from the shower (which was in use at the time). Customer called us out, we were able to fix the issue with a neat 18th edition compliant 2 way board with main RCD while awaiting the DNO's arrival (tails dead of course, due to the fuse failure)  Once again, SSE impressed with the speed of their response, despite knowing it wasn't an emergency.

Yes, we saw one a couple of months ago, caused by a builder not understanding that an RCD, despite being labelled '40A, 30mA' is does NOT contain overcurrent protection, basically leaving the shower protected by the 60 amp BS1361 in the service head.


Also being a builder, he hadn't torqued the terminals.  The result was inevitable... the terminal slowly charred, went higher resistance, got hotter still.. and over the course of 2 days, burned itself clear, whereupon it pressed the now bare live load wire into the earth sleeving.


Apparently the bang was loud enough to be heard from the shower (which was in use at the time). Customer called us out, we were able to fix the issue with a neat 18th edition compliant 2 way board with main RCD while awaiting the DNO's arrival (tails dead of course, due to the fuse failure)  Once again, SSE impressed with the speed of their response, despite knowing it wasn't an emergency.