Hi, all.
A friend has a garage into which he has moved some of his workshop equipment. A seperate dedicated ring for the workshop equipment has been installed.
The house CU is located on the garage wall ( at ceiling level ), and a 32A type B MCB has been added to the RCD side of the split-load CU, in addition to the existing socket circuits. This dedicated ring goes in 2.5 T+E down some trunking to a row of sockets along the workbench. So far, so good.
Now, with kids in the house, he wants to be able to lock off the workshop tools when he's not around, just in case. If we could combine this lockable isolator with an emergency stop, so much the better. At the moment, he has to climb up on the workbench to the CU and flip the MCB, which is a hassle.
So I'm at the design stage.
What's the best way to proceed here?
Should I be aiming to isolate both L+N ( requiring 4 poles of switching for both legs of the ring ) or would switching the lives only be sufficient? We're not trying to achieve 'electrical isolation' in the sense of safe electrical working on the circuits; we are trying to achieve 'machine safe' conditions, where the machines can't operate.
A cheap lockable 4-pole 32 A rotary isolator seems the simplest solution.
For the locakble emergency stop mushroom-head button option, we'd need to add a 4-pole contactor and enclosure to the mix, since the contacts on the e-stop button are only rated typically to operate control gear coils, not full load. So this would be a more expensive option.
What experience to others have of such setups? What would you do?