2 x Main Switches in on consumer unit

[KashBag]

I wondered if it is OK to have 2 x Main Switches in the same consumer unit. One feeding the RCBOs in the House and one feeding the CU in a garage, so that the outbuilding stuff can be isolated from the House CU?

 

[mainline]

I was told that for years, however my house has a few, the DC isolators, the UPS isolator, the DNO isolator etc. And at work one building has at least three DNO supplies, maybe four.

If a board is marked up as having a main switch then it should isolate that DB so that there is nothing live after that main switch.

 

[davesparks]

I was told that for years, however my house has a few, the DC isolators, the UPS isolator, the DNO isolator etc. And at work one building has at least three DNO supplies, maybe four.

Yes, I was referring to simple installations such as domestic as that is what the thread is about. I also said should rather than must because I know it's not always possible.

But as a general rule there should be a main switch to isolate the whole installation, If there isn't then suitable labelling to identify the multiple sources of supply and their respective isolators is required.

Outside of a simple installation it obviously can get a lot more complicated.
For one of my customers the only way to fully isolate the building is a phone call to UKPN to get the 2x 11kV incoming supplies switched off.