What is this all about?

[RedBeard]

This is my first post so please be nice

Came across this setup at a customers house the other day.

Can someone explain why mcb’s/ contactor have been used instead of a wiring centre?

 

[Richard-the-Ninth]

Can someone explain why mcb’s/ contactor have been used instead of a wiring centre

Short answer, NO.
It is not possible for a 2nd person to state a reason why the 1st person did what ever it was they did. All anyone can do is guess, but you will never know which guess is correct.

 

[Geoff1946]

Well I've occasionally done things in an unconventional way simply because I had, "acquired", the components and judged that my way would work as well as any other. e.g. The outbuildings of my previous house, with power circuits all wired in 2.5mm heavy grade 'pyro.

 

[SPECIAL LOCATION]

It you worked out exactly how the wiring is connected..

then drew it out on some paper, you may be able to work out what they were intending it to do??

Otherwise its just pure guess work..

 

[kerching]

Possibly because it's a "Y" plan system and there is no 3rd wire from the cylinder stat for th DHW OFF command and the spark has come up,with an 'elegant solution' ( attb H Wolfe 70/80s )and decided to,also put in MCB isolation/protection

But what do I know?

 

[mainline]

This is my first post so please be nice

Came across this setup at a customers house the other day.

Can someone explain why mcb’s/ contactor have been used instead of a wiring centre?

View attachment 13237

Trace where the contactor is switched on from first, as it could be from another location, and you may not be able to isolate at that rcd.
As I think already said, too many scenarios it could be used for.