Our house was built in 1981 and the DNO at the time, made the decision to install 60 Amp main cut out protection fuses, on the whole of the estate.
Move forward to early spring this year ( 2022 ).
I contacted my DNO and requested a main cut out fuse upgrade from 60 Amps to 100 Amps.
Due to the huge energy price hike in April, we wanted to slide as much of our usage into the 5 hour cheap off peak tariff we are on.
I rang the general number for the DNO and the lady was about as useful as a chocolate fire guard.
Long story, but after a LOT of chasing and phone calls, I did get an appointment to have it done.
When the lads arrived, they asked if I would take a 80 Amp upgrade instead ?.
I said NO - Why ?.
They explained that upgrading it from the current 60 Amp to a 80 Amp fuse, was very easy.
One out - One in !.
But to upgrade to a 100 Amp fuse would require the complete service head replacing.
The 80 Amp fuse WILL fit inside the 60 Amp service head, because the both fuses has the same external dimensions.
The 100 Amp fuse is much larger in its external dimensions and is not a straight replacement.
It has a larger service head, to accommodate the larger 100 Amp fuse.
I explained the reasons how I intended to slide my usage and listed the electrical items I intended to use on the "Off - Peak" rate.
He had already clocked the 7 Kw wall box on the wall of the garage.
Aaarrrhhhh ........ Then yes, you require a 100 Amp fuse to be safe then !.
The whole job was completed in about 25 minutes !.
The hard work was getting an appointment to be honest.