Kojima shows off a new Death Stranding trailer at E3 | Lrd12 Overload Relay

You can get special ground fault detection switches. The circuit at the output of the isolation transformer should be floating with respect to ground. When they detect an impedance between that circuit and ground below some configurable threshold (sometime 5Mohm) they will switch off the power.

The two 120V legs are *in phase* with each other. Residential power in the US is single phase, sometimes called split phase because they’re both 120V relative to the center tapped neutral.

In product safety standards all exposed metal parts are “Bonded” to earth grounded. This is so that if an internal line voltage wire was to contact exposed metal parts the circuit breaker would immediately trip and turn off the circuit. Without Earth ground YOU would be a fuse that completes the circuit.

Larger motors used in rural settings and light industry may aswell use 400 voltage between phases by triangle connection. 3 phase 16A sockets are almost never seen in apartments, but are usually found from houses that have garage or other workspace with larger machinery. Larger 3 phase sockets are very common in farm setting and light industrial buildings. E.g. our hackerspace has air compressor that is fed by 3x 400V 25A line. It doesn’t even have neutral line, motor is connected to triangle and 24V for control logic is stepped down from 400V with transformer.

Please nobody get one of these boards. It is not a safe design for working with mains voltages. This guy has not followed guidelines for minimum creepage and clearances between the low voltage and mains side. You think it’s optoisolated and it may work fine for the majority of the time, but as soon as a mains voltage spike comes along it could bridge the gap and zap your circuit and you if you’re touching it (and your computer if you’re doing doing dev work at the time).

Most hold about 6 to 10 gallons of fuel, enough to run 8 to 16 hours before needing to be refilled. That means you also need an appropriate place to safely store 25 to 30 gallons of gasoline. You could keep just a few gallons on hand and plan to refuel, but remember that gas stations require electricity to operate their pumps. If your entire community is offline or roads are impassible, you won’t be able to get gas.

Bottom line, while the Sony A33′s EVF doesn’t entirely conquer the challenges of its genre, it goes further in the right direction than any other I’ve experienced to date. Most telling is that I now find myself reluctant to give up its benefits and return to world of purely optical viewfinders once again.

My post outlines the PME system. There are older systems that do run an earth / ground but they are being removed as and when they need attention. The US system is different but the number of countries using the US system is much less than the number of countries that use a similar system to the UK. I am UK based and UK trained.

The farther I need to travel to get to you, the more time is taken out of my day—and I’ll factor that into your bill. Finding someone closer to your neighborhood might be able to charge you less.

Optoisolators are designed so that even in failure they are capable of holding back thousands of volts. UL registration demands no less. The same is true of isolated power supplies.

And keep in mind that EVSEs are a continuous duty device. As such, you need to derate them from the circuit’s rating by 20%. So you should only use 12A on a 15A rated circuit. And you should only do that if you’re confident that there’s nothing else pulling significant current on EITHER circuit besides your EVSE.

When we moved from the UK about 15 years ago, we lived in a PME TN-S property and my ex neighbors house is still connected thus. Newbuild and current standard might be to try to retrospectively phase that out, but its still a generalization to say all properties will be TN-C connected. If your in a TN-S property, its my understanding that ignoring that layout and putting your own earthing system in and bonding it to the supply one, can result in ground current back flowing through your system from neighboring properties.