Things Your Electrician Wishes You Knew | 220v Contactor Relay

Tomczyk is a professor of HVACR at Ferris State University, Big Rapids, MI, and the author of Troubleshooting and Servicing Modern Air Conditioning & Refrigeration Systems, published by ESCO Press. To order, call 800-726-9696. Tomczyk can be reached at [email protected] (e-mail).

I disagree, I think L1 EVSE represent a real safety concern. People use corroded outdoor outlets, poorly wired outlets, extension cords (without proper checking for damage or heat build up), etc.

Don’t those wild & crazy Brits use “electrocution” to include a non-lethal shock? Our friend [Moryc] could have learned English from Britlish speaker, as he mentions that he’s not a native speaker of our bastard tongue (though, he could have fooled me with that delightful prose).

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.

If you’re invested in the Alexa ecosystem, the Amazon Smart Plug is super reliable, dead simple to set up, and works with most electrical products you would find in the home. Be sure to heed the warnings found in the in-box manual!

Sometimes you’ll get a zap across your hand, maybe even a horrible burn. But I like those odds compared to you touched live and it routed current through your heart!

I was tasked with doing this last week at work and spent considerable time researching the best/safest way to do it with consumer equipment. As far as I can see the best solution is to use one of the many 433MHz RF controlled power adapters (Watts Clever sell them for as little as $10 each) and use the same record/playback trick used to record TV remote IR signals and play them back with an Arduino. Unfortunately the project requirements changed and I didn’t get to actually implement it but I see no reason why it wouldn’t have worked. Apart from being very cheap (~20 per unit) it keeps the mains voltage completely isolated from everything else, which is particularly important from a liability perspective when you have to deliver the units to an external client.

The main benefits of the RGC..32 include the fact it has the highest amperage rating of any 17.8 or 22.5mm wide solid state switching devices available on the market, DIN rail spacing over 22.5 mm platform, optional cage clamp power terminal for wires up to 3 AWG size, and energy savings due to lower power dissipation.

The UMC equipment included with the Model 3 LR can supply up to 32 amps. That’ll charge at a bit over 30 miles an hour.

I’ve left perhaps the most salient characteristic of the Sony AF55 and A33′s EVF till last: It’s huge. The view through the Sony A33′s eyepiece is much more akin to that of a full-frame DSLR than that of any competing sub-frame model currently on the market. It manages this with a comfortably high eye point (and plenty of dioptric adjustment) for eyeglass wearers, at least when simply viewing the live viewfinder image itself.

Continuous shooting. As well as allowing full-time AF during live view and movie capture, the translucent mirror design of the Sony Alpha A33 brings another important advantage. During burst shooting with continuous autofocus, a traditional SLR has to drop its mirror between each frame, wait just long enough for any mirror vibration to settle, perform the AF measurement, and then raise the mirror again so that the next frame can be captured. Using a pellicle mirror, there’s no reflex mirror to raise, and so the only delay required is to wait for the lens aperture to open after the exposure has been completed. For even swifter burst shooting, the aperture can be locked at either F3.5, or the maximum aperture of the lens, whichever is smaller, removing the delay required to set and reset the aperture to allow focusing between shots. The Sony A33 offers burst shooting at up to six frames per second ordinarily, but with the aperture locked in Continuous Priority AE shoots even faster, providing a very respectable seven frames per second. (Its sibling, the A55, is even swifter with a whopping ten frames per second in Continuous Priority AE mode.) Sony also notes that, for like framerates, the autofocus system in the Alpha A33 can be active for a greater proportion of the time compared to a traditional SLR, providing more data from which to make AF tracking predictions.

Eh, boneheads frying themselves or setting their houses on fire because of DIY approach to mains wiring are hardly something new that can be blamed on the “maker movement”.