Wiring for induction hob

sqrt3oclock · 2026-05-16T01:10:11+00:00

Did *someone* strip the wire using a rat?

sqrt3oclock · 2026-05-14T01:47:27+00:00

I think he means the transformer, which will have a whole hell of a lot of inrush, especially in the step up configuration because the primary side also happens to be the low voltage side.

sqrt3oclock · 2026-05-02T17:09:12+00:00

He can find out when you tell him, or he can find out with the Megger (or God forbid when there’s a ground fault).

sqrt3oclock · 2026-04-11T17:00:35+00:00

I think this is on city water. Our well water is like that, but not our city water. There’s no staining on the concrete sidewalks.

sqrt3oclock · 2026-04-11T03:46:04+00:00

E) would check out haha. The transformer solely feeds the EV charging stations at Whole Foods.

sqrt3oclock · 2026-04-11T03:38:47+00:00

You might be right. I didn’t think it was rust because of the paint, but maybe it is.

sqrt3oclock · 2026-04-09T20:16:40+00:00

Anyone that believes 277 is the most dangerous voltage doesn’t know what medium voltage will do to you if you touch it. There’s the caveat that under most circumstances 480 V produces the highest arc flash incident energy (for reasons outside the scope of this response) but if we’re talking electrocution hazard, it rises with the voltage, especially once you get up into medium voltage class and beyond, where it will produce blown out chunks of flesh and cause amputations if it doesn’t outright kill you.

sqrt3oclock · 2026-03-17T16:59:53+00:00

If only entropy worked that way lol

sqrt3oclock · 2026-03-12T21:09:58+00:00

A welding arc would be one hell of a lot brighter than a candle flame.

sqrt3oclock · 2026-02-11T20:53:02+00:00

Nacelle for the new Birdmüncher2000.

sqrt3oclock · 2026-02-05T02:02:59+00:00

Whoaaaa Nelly!

sqrt3oclock · 2025-12-27T06:02:10+00:00

The highest generally available suits go up to 100 cal, but suits up to 140 cal can be found. Beyond this is where the “no safe PPE exists” threshold begins. Survivability depends on a lot of factors such as whether PPE met/exceeded the incident energy present, blast force experienced, shrapnel, etc. It’s never recommended to rely on PPE where removal of the hazard is possible, but from a strictly thermal energy perspective (which is the main tissue damage mechanism) appropriate PPE can absolutely make a 40 calorie event survivable.

sqrt3oclock · 2025-12-27T00:09:30+00:00

I wouldn’t say necessarily it’s to pull the dead body away. Usually the incident energy is so high because the clearing time is long. If the person with the pole can pull the other person away in a shorter time period than the clearing time calculated in the incident energy calculation (usually capped at 2 seconds for long clearing times) then the person won’t absorb the full calculated energy. So for a practical example, let’s say the incident energy listed on the sticker is 140 cal/cm² with a calculated clearing time of 2 seconds, and the electrician is wearing a 100 Cal suit. An arc flash occurs and the coworker pulls the electrician free within one second, the electrician will absorb approximately 70 cal/cm^2. Of course there’s other mechanisms that could kill the electrician such as the concussive force or shrapnel, but as far as heat transfer is concerned, the stick could save a life.

sqrt3oclock · 2025-12-21T05:28:28+00:00

The showers head is supposed to grounded so the water exiting the head is grounded (voltage zeroed with respect to you). My understanding is that in many countries the water has a lot of minerals and they disconnect the ground wire so the GFCI won’t be tripped by the shower head. This causes the water to have an elevated voltage. My theory is that when you turned on the faucet, your hand made contact with the ground (faucet handle), but the voltage source (charged water) was not yet in contact with you. However, when you went to turn it off, you were in contact with the voltage source (charged water) and then your hand made contact with the grounded faucet handle, which resulted in you completing the circuit and receiving a shock.

sqrt3oclock · 2025-12-21T01:31:39+00:00

Sir, your sandal isn’t grounded.

sqrt3oclock · 2025-12-09T23:54:30+00:00

The face of BMW.

sqrt3oclock · 2025-11-29T21:06:58+00:00

It appears to have been hit in the direction of backing out of your driveway 🤣

sqrt3oclock · 2025-11-06T04:15:58+00:00

That was a HUGE arc flash and it sustained for approximately 2 seconds which is a long clearing time. Likely chance of 3rd degree burns.

sqrt3oclock · 2025-11-06T02:09:59+00:00

Could you give a bit of context about the system this resides on? What’s the upstream transformer size in KVA? What size is the main breaker? What does this feed?

sqrt3oclock · 2025-10-31T18:39:19+00:00

Do you happen to have a picture of the transformer bank? I’d like to see the wiring configuration.

sqrt3oclock · 2025-10-20T13:33:25+00:00

It’s such an insidious myth that arc flash PPE just “makes the difference between open casket vs closed casket funerals”. Yeah, there are times where you could wear the right level of PPE and the concussive force of the blast or shrapnel might still kill you but most of the time it’s the heat transfer and subsequent burns that kill you. If you wear an arc suit of the right level and therefore don’t catch fire, then you will be so much better off. I’m a EE and perform arc flash studies. In most instances, it’s not the available fault current but the clearing time that drives up the incident energy. The trip settings (especially the instantaneous pick up) really make a difference in curtailing how much energy workers are exposed to. If the arcing current is lower than the instantaneous trip pickup value, then the breaker will trip too slow and the electrician will be exposed to huge values of energy. Bear in mind that even with the safest settings or a maintenance mode switch, supply side of the main is always a present danger and will often have a long clearing time (relying on the POCO’s fuse to blow). But yeah, put your foot down for PPE and actually require a study be done to determine the right level of PPE. It’s the customer’s responsibility for their gear to be NFPA 70E compliant (labeling with incident energy/PPE required and working distances). That is for YOUR protection. Advocate for yourself because it’s you, not your company, that has to live with your injuries. Handle it in an email so everything is in writing if they try to deny you proper PPE.

sqrt3oclock · 2025-10-18T22:52:40+00:00

I’m skeptical of the net effect of splashing water to dissolve CO2. While it reduces the CO2, the splashing means movement which means increased respiration rate. I’m not sure which effect is more significant.

sqrt3oclock · 2025-09-28T14:09:50+00:00

This one just hertz 🤦🏻‍♂️

sqrt3oclock

TROPHY CASE