Things Your Electrician Wishes You Knew | 19mm Momentary Push Button

I have seen a 10cm hole blown right through the middle of circuit board. I have had many repair jobs that it’s been obvious that lightning has hit the overhead power lines, exploded parts, vaporised PCB traces. Non of these had any negative outcomes except having to repair the device or throwing it in the bin, generally the latter.

People are so fixated by the calculation of amount of liquid per mile, they can’t–and won’t–figure it out on the basis of how much money it costs to drive each mile.

I have never understood why North America stayed in their stupid 120V system, that uses very high currents over inferior aluminium wires, connected with lose screwcaps and fuses that may explode out of the wall. And it would be probably federal crime and against the code to use proper copper wires connected with good push lock blocks and DIN rail mounted fuses and contactors…

Hey [Martin] I think you deserve some recognition for your contribution here tonight (or whatever time it is for you).

Depends how far north you are – direct sunlight isn’t required for them to produce useful heat. If you’ve got a months long night then they’re no use though.

And the MOC3041 can not handle a 1 amp load, “Peak repetitive surge current” is what it can handle for 0.0001 seconds at every 60Hz cycle before getting (possibly) damaged. The continuous load limit is far less than 1 amp.

If you had the choice between two identical-looking boards, with the same pictures, and review ratings, would you spend an extra 20¢ on the more expensive one? That twenty cents really adds up, you know- if I was buying 1,000 ESP-12 boards, for example, that would be two hundred dollars saved, and you would be pretty happy with yourself. That is, if it works. Otherwise, you feel really dumb.

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”

I’m not claiming this is a new phenomenon (I’ve done some stupid things with electricity myself, before the www was even invented) but we know that the media isn’t always rational about these matters.

It works, but the losses are significantly higher, and if you’re drawing much power you’re going to need heavy, expensive low-voltage sides on both transformers. In a pinch, fine, but if you’re going to be buying them it’s better to spring for a single transformer.

The U.S. benchmarks are approaching the unofficial start to summer amid characteristically range-bound, and slightly sluggish, price action.

By not distributing the three wires and only distributing two you try to limit the possible potential between neutral at the sub and neutral at the house by using multiple earths anywhere you can so in this case when lightning strikes the local ground potential rise applies to the ground and to the local end of the neutral/earth wire. Massive currents may flow through that neutral/ground and eventually through the low value resistor at the substation but under no circumstance other than network failure is it possible to get a neutral ground potential of significance with a premise. The low value resistor at the sub limits the current to one that the network can handle.