Turn a wall outlet into a wireless charger with the Legrand Radiant | 19mm Momentary Push Button

Back in the day the UK before EU harmonisation the nominal single phase domestic voltage was 240V ac and within a range of +10% and -6% ie 264V and 225.6 V Under EU harmonisation it is 230V +10% and -6% ie 256 V and 216.2 V. I can assure you that voltage control at Primary substations in the UK 33KV/11KV was lowered to the new nominal for the nominal voltage at secondary substations 11KV/415V/230V. A good thing really as it saves energy

Pedantic FWIW: Afghanistan and North Korea and some banana nations use 110V. USA uses 120V/240V. Japan is the oddball, using 100V. Annoying because you can’t draw more than 1 kilowatt from a socket there (kettle, hair dryer, space heater…). And having lived with the three voltages (100V, 120V, 240V) on four continents, I’ll happily take the 120V supply instead of the 240V.

It’s good to see a snubber on the design (that’s often omitted on DIY designs I’ve seen). There are a few TRIACs that are designed to commute highly-inductive loads (“snubberless” is the marketing term I’ve seen) — may worth looking into them to reduce the BOM.

You likely encountered a shared neutral between more than one circuit. You have to switch off the breakers for all the circuits that share the neutral.

With the start capacitor out of the circuit, the motor becomes a permanent split capacitance (PSC) motor in the running mode only.

If you had a mains-voltage shock once and got away with it, you were lucky, that doesn’t mean the voltage is safe, you were merely playing a game of Russian Roulette with Ohm’s Law and a low impedance high voltage supply. Your domestic mains can dump the hefty amounts of current your home heating, your cooker, or your electric kettle demands, so if it finds a low resistance path through you then it is going have no problems dumping whatever current Ohm’s Law allows it to through that path. The chances are if it happens to you the path will be a high enough resistance that you’ll only get a very nasty jolt and live to tell the tale, but if it’s not your lucky day the resistance will be low enough that you’re just going to sit on the end of it twitching until the power is turned off, whether you’re alive or not. That’s the gruesome truth. Mess with this stuff and you can die, end of story. You are responsible for keeping yourself safe, and this is not a joke. OK? Now to work!

My situation is a good example. I just purchased a new house and unfortunately it does not have a garage. Until I get the garage built in the Spring with a NEMA 14-50 outlet, I’m going to rough it with L1 at 120V/15A.

I also seen a technique where a relay is placed in parallel with the zero crossing triac so the triac is only passing the load for 200ms or so while the relay switches. Since the triac is on longer than the relay, the contacts don’t arc over when switching, and the traic doesn’t pass the current all the time.

It may be just perception coloured by the general work environment, but a lot of the US regs seem driven by liability concerns. Too many lawyers.

I would like to add that it’s not just electricity you need to worry about. There could be other energy sources present from things like air, springs, hydraulic, etc that could pose a safety risk when you remove the electricity.

A vaccum forming table design I looked at used ceramic rods made the same way with reflectors to evenly distribute the heat. I also own an electric kiln designed to heat and temper glass so a page can be taken from that design.

Also, when you say “..10A relay will dissipate maximum 2.5W through the 0.1ohm contacts…” also does not seem to be correct: P=R*I^2, so @10A it’s 10W