Microsoft and Razer are working on Xbox keyboard and mouse support | Lrd12 Overload 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.

The ones I’m talking about, they’re ubitquitous, supermarkets have them, don’t do dimming, just on/off. They seem to use a relay, from the clicking they make. I don’t think this one does dimming either right?

Ah, right you are. I’m out of date — I last dealt with UK power in 1981, and have not been back since. Thanks for the update.

So, you agree with 3mm. Good. A step forward. And because I see you want to use that Industrial standard as example how is your standard looking in case of soldermasked and conformal coated board? What I can say is that I used the 3mm/kV rule and never failed me in 25 years, no board rejected ever…and for the sake of the discution, as you know, when we are under 500V/10A circuits things looks a bit different in PCB Design. We are not sending nobody to the Moon nor switching a 500A Engine starter. It’s a max 300W lighbulb Switch and it’s 99.99% safer than the latest zilions of made in China dimmers and fake USB SMPS Mobile Chargers that arrived in your city in the last month.

I’ve used 220V heaters to cook meat and I survived (quite well fed) up until now. I suppose heating a piece of plastic can’t be that much more difficult, although wh

I think that one of the statements that stuck with me the most while doing LV operations training was from a doctor who said “If you are admitted to my hospital with electrical burns then I will do my utmost to make sure that your family get here before you die”

If the device does not have it owns fuse/breaker and relies on the upstream one, it had better be able to handle the full rated current without catching fire.

Andrew, here in the Land Up Over, Most residential power is single phase, A step down center tap transformer (pole pig) puts out 240 VAC from end to end and 120 VAC with respect to the Neutral (ground) center tap. Therefore the two phases are 180 degrees out of phase. These 3 wires are fed to the fuse box/breaker panel in the house. One hot goes down one side of the row of breakers and the other hot goes down the other side. Neutral is common, Ground is also in there, but whether it is connected to Neutral inside the Breaker Panel or outside may differ according to local regulations.

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.

Upgrade the triac and redesign the PCB to be able to safely take a whole 2400W (Australian 240v 10A mains rating) of mains load.

There is a lot there, but here are two highlights that directly apply to you as an HVACR professional. This comes from the 2017 edition of the NEC NFPA 70.

And because what you need is power and not current, and because of voltage drop in your wiring, the current is slightly more than twice. If you have a load of 1200 Watts, so 10 A in 120VAC and 5 A in 240 VAC. With wire around 8 ohms/km (roughly wire of 2.5mm² section or 14 AWG), you get a voltage drop of 8 Volts in one case, 4 Volts in the other. So 6.67% of your main voltage vs. 1.67% of your main voltage. Already 5% of efficiency loss in your system… But it’s even worst because in this case you don’t get 1200 Watts at your load, only 1120 Watts ((120-8) * 10) and 1180 Watts ((240-4) * 5) To get your 1200 Watts at your charge, you need 10.77 Amps and 5.08 Amps. So you get a overall efficiency of 92.8 % at 120 VAC (1200 / (10.77*120)) and 98.3 % at 240 VAC. (5.5% of efficiency difference).