Heavy Lift Electromagnet from Microwave Oven Transformers | 25 Amp Circuit Breaker

I am certainly not suggesting HVACR techs engage in performing work outside of their skills or licensures, but, in many cases, being able to identify the problem and making the repair are two different things.

Pedantic FWIW: Afghanistan and North Korea and some banana nations use 110V. USA uses 120V/240V. Japan is the oddball, using 100V. Annoying because you can’t draw more than 1 kilowatt from a socket there (kettle, hair dryer, space heater…). And having lived with the three voltages (100V, 120V, 240V) on four continents, I’ll happily take the 120V supply instead of the 240V.

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You can get special ground fault detection switches. The circuit at the output of the isolation transformer should be floating with respect to ground. When they detect an impedance between that circuit and ground below some configurable threshold (sometime 5Mohm) they will switch off the power.

I had my own suggestions further up in the comments here, and I’d like to believe I expressed them respectfully, and TJ addressed them. And, as is appropriate, the article text has an exhortation to not play with HV power without due care.

But yes, 1A is the absolute maximum, peak value for the MOC3041M for a brief amount of time. Even the MOC3041’s 8A maximum, temporary rating is unsuitable as a peak for a typical 15A US mains.

Agreed, the component is under rated from the start. If you look at a datasheet from a 25A SSR from a better company you will find something like de-rating curves which really show that as you move from the ideal conditions (20C temp, infinite heatsink) you should only use a smaller load. It is pretty easy to reach a limit of half the max load in normal conditions.

I have to say in this case it’s probably a necessity to get anyone to look at the photos, so humdrum is the subject matter

But at the very same time, if the rectifier dissipates enough energy for this to be a concern, then it is probably a poorly designed power supply to start with. As most power supplies will be designed for the voltage range of 110 to 250 volts AC. And as it will draw the most current down at 110 volts, then this is where the manufacturer has their specifications chiseled in stone, as if we want 1100 watts, then we need at least 10 amps when we have 110 volts AC on the input. This means that we “effectively” have 5 amps to dissipate per diode.

not exactly mains but when i was a kid i enjoyed playing with photoflash caps and at one point had one fully charged to about 330V and discovered the negative post to the AA battery was also connected to the cap and put the entire shot up one arm, across my damn heart and out the other arm, my whole body locked up for only about a second (maybe 2) and i think i fell over (like people in taser videos but i was sitting). it sure shook me up and im glad it was only a small cap

A steamy day on the flat roof of a building will let you feel how many inches the 480 can sting your fingers from also.

Cooking Triac? In my experience there are only good Triacs and bad Traics. You can tell the bad Triacs because they usually have a a little bit of plastic encasing still attached to the three legs after they have exploded.