Turn a wall outlet into a wireless charger with the Legrand Radiant | 220v Contactor Relay

We were pretty close to that 40% rule when our controllers started to fail, which is probably why they only started failing after our customers had use the controllers a few times. We were pushing 22 Amps through 40 Amp rated parts. In other words, using a component at half its rating still won’t cover for substandard parts! Our solution was to find a part that was manufactured to spec and also use the component at half its rating and we’ve not had a verified SSR related failure since.

I suppose the other point of note is that compared to 220/230/240 Euro voltages, residential 240 is not 240 to ground. The only things that have such high voltages to ground are either corner-grounded 240 deltas (which are exceedingly rare) and 480/277Y systems (which admittedly I do a lot of work with). I also really like how in the US we have such an extensive system of completely non-interchangeable, unique connectors for all the different voltage and phase combinations that one might find (thanks, Harvey Hubbell!)

I’ve spent four to eight years in apprentice school learning how to plan, install, inspect, and repair electrical products. Don’t insult my intelligence by implying otherwise.

The Death Star post illustrates why we shouldn’t let economists decide how to run things. That and a million other stories from real life.

I think Brian’s point was that if the bond between the earth ground and the neutral return of the incoming premises power isn’t good enough, then the short to earth might *not* trip the breaker. Of course, it would likely start a fire instead (the resistance may not be zero, but it will be low enough to sink a great deal of power in most cases and a 15A breaker will tolerate a couple THOUSAND watts), but I think that if you can’t trust that the building is to code, then all bets are off.

Gasoline-powered portable generators, which cost from about $400 to $1,500, based on their output and features, are not only readily available at home-improvement stores, they’re easy to use. “If you can operate a lawn mower, you can operate a generator,” says Art Aiello, spokesman for Generac, one of the largest manufacturers of portable generators. “In winter, it doesn’t take a lot of snow or ice to bring down a power line in certain neighborhoods. If you have the ability to pull it out, add fuel and attach extension cords, a portable is a sound solution.”

Video capture is an area where the Sony A33′s translucent mirror technology makes a huge difference relative to pretty any other SLR currently on the market, and relative to even fast-focusing SLDs. Every other interchangeable-lens camera currently on the market either doesn’t autofocus at all when recording videos, or has to resort to slower and/or more obtrusive contrast-detect focusing. Because the Sony A33′s phase-detect AF system is always looking at the subject, fast autofocus during video recording is no problem.

The triac can handle 8 amp continuously and upwards to 60 amps in surges. But the 8 amp is if heatsinked enough. If you insist on a 15 amp capability replace the triac with a 25-30 amp model instead. But will *still* need heatsinking. I triac usually drops upwards to 1 volt, so pushing 15 amps in a triac regardless of size will generate up to 15 watts, and that will generate a *lot* of head in a hurry.

Still, most capitalists, when you order something, don’t ask “what do you want it for?”, so they can substitute something else without telling you. Generally in contracting with capitalists, mysterious “problems” don’t regularly as clockwork pop up, increasing the cost above what was agreed.

Where I do agree that it is under rated, as far as I know, Mathias is an electrical engineer. So he should be able to work with mains, and he should also know better.

well, originally they were 2 kW transformers (or at least from microwaves that are rated to 2-2.5 kW), and on secondary is wounder stranded thick wire (diametar around 7-8mm)… enought power to melt nails with 3-4 mm diametar…

An emergency isolation switch. Santeri Viinamäki [CC BY 3.0], via Wikimedia CommonsYou will be familiar with emergency isolation switches if you have worked with large machine tools. A big red switch designed to be easy to hit to turn all the power off. You may want to hit it if something gets out of hand, or someone else may want to hit it for you to turn off the power that is electrocuting you. Either way it provides a very quick way to manually make any mains sources on your bench as safe as possible in the event of an incident. Remember the bit we mentioned earlier in about sitting on the end of the line twitching until the power is turned off? This is the big red switch that makes it very easy for someone to do that for you.