Isolation

The risk of an MCB or a switch is that an unskilled person may re-energise it while it is not safe to do so, and at the worst case, you are on the other end of it when someone resets the wrong breaker.


An unskilled person will not be opening the box to re-attach cables that have been removed and tied back. (Personally I tend to Wago things together that are out of use and maybe earth them if the run that would otherwise be floating is very long.)

So it is perfectly acceptable as a means of isolation.

The caveat is that whoever does the isolation now has to be more skilled than just padlocking  a switch paddle, as now they need to open the box, up, and not upset anything except the desired circuits,  and quite possibly do that with incoming bus-bars alive, depending on the design of the units.

Anyone who can use a key can lock off, while you need a sparks, and for some situations, perhaps a change to the live works policy, to use this method.

The risk of an MCB or a switch is that an unskilled person may re-energise it while it is not safe to do so, and at the worst case, you are on the other end of it when someone resets the wrong breaker.


An unskilled person will not be opening the box to re-attach cables that have been removed and tied back. (Personally I tend to Wago things together that are out of use and maybe earth them if the run that would otherwise be floating is very long.)

So it is perfectly acceptable as a means of isolation.

The caveat is that whoever does the isolation now has to be more skilled than just padlocking  a switch paddle, as now they need to open the box, up, and not upset anything except the desired circuits,  and quite possibly do that with incoming bus-bars alive, depending on the design of the units.

Anyone who can use a key can lock off, while you need a sparks, and for some situations, perhaps a change to the live works policy, to use this method.