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

In this context, “voltage transients” are defined as short-duration surges of electrical energy. In the electrical or electronic circuits that varistors intend to protect, this energy may be released either in a predictable manner via controlled switching actions, or randomly induced into a circuit from external sources. Common sources include:

253V above. The 3% voltage reduction equalled 5% of the load and 6% voltage reduction 10% of the load I seem to remember. Over 15 years ago.

However, there’s a reason we use 12V and 24V heated beds – they give us, at the very least, the illusion of safety. Therefore, [Makertum] is looking for a few comments from specialists and people who know what they’re doing.

1. Metal-oxide varistors (MOVs) are available in a variety of form factors and sizes for a broad range of applications. The radial leaded disc type is the most common version.

If a consequence is human death then obviously that is completely unacceptable. If it blows a fuse at 1000V then good! If traces vaporise disconnecting the mains at 10,000Votls then well done! Where is the weakest point (lowest creepage clearance for the exposed voltages) and what are the consequences of a flash over at that point.

I know a lot of people that have never heard about “makers” but I wouldn’t trust them near any mains wiring – like my own dad who has wired a circuit breaker between live and neutral. Only the ensuing BANG and my mom’s swearing and yelling from the now dark kitchen have disabused him of the idea that that is how it should be done.

https://www.ul.com/newsroom/publicnotices/ul-warns-of-solid-state-relay-with-counterfeit-ul-recognition-mark-release-13pn-52/

Is anyone else bored of these manufacturer-supplied "scoop" shots of vehicles with a bit of swirly wrap stuck to them?

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.

This is a heater that’s going to be near fingers, or elbows, and is completely accessible to them, completely easy to touch. One day, when he’s distracted thinking about something else (not rare), he’ll end up touching the heater and getting a shock.

I use these kinds of SSRS in high current applications driving kilns. we protect ourselves quite happily by having a contactor in the line. The SSR when it fails fails ON and the contactor is help closed all the time but overtemp or any other kind of alarm will release teh contactor and break teh circuit. My recommendation – and no one wil ever get to the bottom of the comments on this feed – is to add a contactor in series which is help closed and opened in an alarm condition. Then the SSR can fail to its heart’s content and you’re good. The SSR is of course much better at switching on and off than the relay which will fail eventually from on/off transients. As usual – YMMV

Yeah just what we need – another dopey ‘standard’. Putting stuff in right and using proper equipment is and has always been the solution.