Garage Wiring- The Plan

It also protects the supply cable too. If the downstream supply exceed the MCBs rating then the supply cable is protect, if the cable is higher rated than the total of the garage CU MCBs. That is abundantly obvious.

In the garage situation, if the supply cable is rated higher than the total of the MCBs in the garage, it is protected, whether upstream or downstream. It is just simply protected. It cannot be loaded up above its rating.

The what hapens if the house burns down. What you are saying is that every CU should have a protective breaker between the meter and the CU.

That is not the purpose and not how electrical systems are designed. THe circuit protection is installed at the supply end of the cable.

That is not correct design. Refer to BS7671 and publications derived from it.

No he isn't. The protection for the meter tails and CU itself is the supplier main fuse.

It *may* protect the supply cable under *some* fault conditions. However since it is not able to give adequate protection in *all* fault conditions is it not relied on.

The correct design approach is to protect at the origin only. Any side benefit you get from a downstream protective device is just that, a side benefit not something you rely on.

Obvious yes, but dangerously neieve.

There are issues here you are failing to grasp. Firstly meter tails are sized such that their capacity exceeds the main fuse rating. In a fault condition the main fuse will operate before there is risk of these causing a fire.

A sub main feed to an outbuilding is unlikely to be sufficently large for this to be the case. Hence it must have its own dedicated overcurrent and earth fault portection at its source. You can ignore anything on its destination end since you can't rely on the fault occuring after the destination - you have to considde fault conditions that affect the cable itself, or the CU it terminates in.

No, that is what the main fuse is for. You only need additional overcurrent protection and isolation between the main fuse and the CU if the CU is more than a couple of meters from it.

Conduit can never look as neat as SWA on the average run to a garage since it will inevitably have bends or elbows.

Plastic conduit - the only sort Evil is likely to use given his poor skills - will look even worse, and not give anything like the same protection to mechanical damage as SWA. Then there's the problem of pulling through TW&E, and the fact that the ECC in all probability won't be adequate. And the combination costs more as well as being more labour intensive. A lose lose lose situation. So typical Drivel.

Something this obvious a child would have no problem understanding.

Wishful thinking!

Yup, that is what SWMBO is for! ;-)

No error in my suggestion to the OPs problem.

IT is clear you don't know much about this.

Not for aesthetics.

Are you saying it would not be protected?

As per the garage too.

But protected. That is obvious

Yep.

You size to suit. I have said that all along. In this case the supply is high level conduit.

Bends and elbows? You don't say.....

snip idiotic drivel

More lunacy snipped.

So many to be positively dangerous. Luckily, most here know you for the charlatan you are, and ignore your 'advice'.

It's clear you know nothing about electrics. And by default, little about anything else.

You've made about 6 different ones, all of which have either had unsuitable or dangerous information or both.

It's a lot less conspicuous than conduit.

This man is deranged.