I don't see why it would crack, you might be able to crack thin cast by lumping it with a hammer but I wouldn't expect it to crack from a small hole even if the saw bites, but you could turn down the torque to be sure
That's nonsense.
It's confusing the way you're writing this as if it's one switch - I'm assuming from your description this is a 2 gang 2 way faceplate. If the problem you're having is with the right side switch, try swapping the 2 black cores.
If the left side switch is working correctly then don't touch it...
Possibly, might mean you're sort of quenching the metal. I drill a lot of stainless at work and never use water or cutting fluid, you just need to keep an eye on it because when it stops cutting its heating and you'll never get through it. Those carbide hole saws are the tits though, drilled...
30 minutes rofl. Cast drills easy with a sharp drill and you should be through it in seconds if it's cutting. You'll have work hardened that spot now and it will likely be very difficult to drill. Try a brand new drill roughly the size of the pilot in another spot - slow speed setting and good...
@JohnW2 I would say a C3 is anything which isn't likely to be dangerous at this moment in time, but which an improvement would enhance the safety of or bring up to current standards.
You make a good point though because I likely wouldn't code a fixed socket although being off the floor is...
Unsuitable for location with regards IP ratings etc. That could be considered C3 as that reg was no doubt introduced at some point.
The only reason I wouldn't code that would be laziness, which I'm not immune to.
Not really imo, there's plenty of hard and fast rules in the regs (max zS values for instance) but equally there's lots of regs where competent persons are encouraged to use their judgement. I'm pretty sure I could find reasons to c2 a loose socket on the floor underneath a washing machine...
Something like these mini grid modules. Get the 3 module faceplate, a dimmer module and mounting kit (2 modules) and retractive switch (1 module). There's a good chance you'll need to fit a deeper backbox though, they recommend a 47mm but you might get away with 35 if you've got one already
Seems to me you already have a pretty good understanding on a practical level. Have seen you helping people on a lot of threads with thermostat and programmers, you'd be surprised how many electricians struggle with basic control systems.
Most of the rest domestic wise is just knowing what is...
It wouldn't work in its current iteration, but maybe the unit failed and someone has bodged it with the rocker switch poorly. What I would do is order the shelly relay I posted and fit that inside your door opener box. You can remove the PCB if it's in the way. I'd also buy a 3 amp fuse and...