Do you have to sign and promise that only some of your electricity will used their fuse?
Don't be silly.
You have to sign and promise that you will abide by the terms and conditions that THEY set if you want to use THEIR network.
But you know this. It's not that you are so stupid that you don't get it, it's that you don't like it, and you are so childish that you think that if you raise enough stupid objections, and ask enough stupid questions then somehow clauses a company has in its contract with its customers will just vanish.
You're also not so stupid that you don't know that, but nevertheless you keep raising stupid objections and asking stupid questions.
It is not nonsense that a company can have terms and conditions in a contract which you don't like. What
is nonsense is you thinking that somehow you not liking them, or you not seeing a justification for them, means that they can be disregarded.
It's not that you are so stupid that you don't get it, it's that you don't like it, and you are so childish that you think that if you raise enough stupid objections, and ask enough stupid questions then somehow clauses a company has in its contract with its customers will just vanish.
You're also not so stupid that you don't know that, but nevertheless you keep raising stupid objections and asking stupid questions.
How does what work? A rule which says that you can't have meter tails over a certain length without your own fuse? Probably not very well.
and how does their fuse know.?
It doesn't. But you know that.
It's not about which fuse "knows" to blow. But you know that.
Have you read what I've written above about your stupid questions?
But - how do they prevent it being used?
They don't. But you know that.
It's not about that. But you know that. And yet here you are asking another of those questions.
None of these variations explains the need for two identical fuses in the same place.
And none of your questions and objections have made you look cleverer than any supplier who does have such a rule.
It just makes you look like a petulant child who keeps on asking "Why?" "Why?" "Why?" "Why?" over and over again.