Recent content by cycle61

That's insulation tape wrapped in layers around a bus bar. The missing bit near the bottom is where the arcing eroded it away. Edit: I missed the earlier responses. Ola as usual brings the detailed theory explanation.

Really high voltage does some weird stuff, and definitely doesn't behave the way we might intuitively expect. Like jumping an air gap instead of going around a curve in the cable. Oops. This is another favorite, although at only 15,000 volts it isn't nearly as crazy. The sharp corner of the...

This is the kind of detailed, specific knowledge that I love finding in these kinds of threads. Well done, internet.

There's not a surge protector in existence for residential equipment that will protect against a direct hit like that. Hopefully your insurance takes care of you.

Fortunately no. CycleWife is home and the printer is now safely in the house.

It's here! :bounce: But I'm out of town for a few more days :cry:

We just buy whatever looks decent at Walmart when it’s time. Picked up a 10x12’ yesterday, that’s a size I hadn’t seen before and may offer a bit of extra space and flexibility. They’re all disposable under heavy use. If we get a year out of one before a gust of wind folds it up that’s a win...

Well, after a couple years tinkering with a Prusa MK3 it's finally time to step up to a more professional printer. The Bambu X1C is on sale right now, and we ordered one for the shop, along with a roll of ABF-GF to test out a bunch of parts. Gets here Wednesday but I won't be home to get it...

Well, ordered a Bambu X1C this morning. The Prusa Mk3 has had a good run, but we need something that’s more capable and less science experiment.

There are two bolts on it that connect to a small lead. There’s also a whole panel missing that normally separates the MV and LV compartments. I don’t share full resolution pictures since they occasionally contain client identifiable information.

Definitely not the case here. I checked my notes and this system has a high resistance ground for the X0 to provide voltage balance with reduced fault current possibility, and an alarm connected to the HRG to let the operator know if anything occurs.

And when using open delta potential transformers with a grounded B phase, it’s critically important to program your meters and relays correctly or else they will display an unbalance when the system is actually fine. Many clients some technicians get confused by this.

Ahh gotcha. Typically the ground-neutral reference is established both at the transformer (in this picture) and at the service entrance (a switchboard somewhere downstream). There is probably a small 4/0 jumper or strap between the X0 and the ground that’s not readily visible here.

Medium voltage shielded cable requires grounding of the braid at both ends. This is a pretty common setup for this class of equipment. There are also surge arrestors on this transformer which each get grounded.

What could go wrong? 🤨