Looking Mains Voltage In The Eye And Surviving | 220v Contactor Relay

The standard phrase in our repair shop was “electroplated’… as in …”I took that old CRT out and whoosh…. I damn near electroplated myself into the middle of next week when I touched the bottom of the LOPT”…. electrocution was reserved for politicians… as in “….how the hell could there possibly be enough numpties in this country to electorcute that old hag Thatcher…”

HVDC interties certainly simplifies some things (stability, voltage control, and frequency syncing & phasing is a non-issue), particularly in lines where their length approaches a quarter wavelength (which makes voltage control at the load end difficult). There are quite a few already: http://en.wikipedia.org/wiki/List_of_HVDC_projects and the list is growing rapidly.

Step 1:  To find the voltage rating of the MOV, allow for 20% headroom to account for voltage swell and power-supply tolerances: 24 V dc × 1.2 = 28.8 V dc. Given that no varistors have a voltage rating of exactly 28.8 V, check the datasheets for specifications for 31-V dc MOVs.

It happens to the best of us. We power up our project and immediately run into issues. Be it spotty communication or microcontroller reset or any number of bugs that have us mystified and picking though our code… only to find that it’s a power supply issue. Anyone who has tried doing Raspberry Pi stuff and depended on the USB power from their PC has certainly been bit by this.

I forgot to say that 220 volt AC is effectively 310 volts peak, so therefor one could instead use 300 volts DC instead, giving roughly 25% less current to carry in the wires to get the same power in the end.

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Thanks for letting me know about the typo and qualifier on the 208V part. I’ve updated it in the article.

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The melted solder was probably a secondary failure. When SSRs fail they often turn into heaters as his did and the heat from the base plate itself melted the solder before incinerating the plastic housing.

While if we take the same supply and drive it with 300 volts DC, then it will only need a bit less then 4 amps. And this is in fact going to put our rectifier under less load then when we run it with 110 volts AC.

He’s not using a pool side remote box but emulating it. But what if he wanted to use both? At the moment it’s simulating the buttons. What if you need to both simulate the buttons and also read them if they are pressed?

Not to be argumentative, but please show me a case in which a H/O policy denied coverage for a fire loss because the homeowner used a non-UL listed device. H/O policies are contracts, strictly regulated by each state’s insurance department. The vast majority of H/O policies are “All Risk” based, meaning that you are covered for everything unless there is a specific exclusion for it. I have read many times on this forum and others about H/O policies not covering such claims, please show me ONE that actually is true. There may be one out there, but I have never seen it.