Welcome to the world of SMD codes, lol. I couldn't find anything matching BV9K3B. Capitals often matter.

imgur.com/gAmdpub

Finally got my image up

@rdtsc Thank you! I already tried a basic google search, so my next step is kindof to figure out the manufacturer and ask them.

Ahha... it's a Chinese "Alpha and Omega" brand. Hopefully that helps. :)

@rdtsc prooooo

they're open, giving them a call

Left a VM.

Hope they return your call quickly. I've never called them so unsure how their support is.

I ended up googling Alpha Omega 4614, seems to be an AO4614B :D

matches up with the use in circuit, 4 pins on drain on top. and the others on s/g

you were super helpful

hey there @rdtsc and @Marla

Hello, would the following question be a good fit for this site? I think it is related to control-theory, but I am not an expert in that, so I'd like to hear your opinion.

Hey Shalvenay, how you been? :)

@rdtsc alright here, pondering a listing/labeling conundrum that seems to get stranger and stranger as time goes along

Would that be how to label a transformer? (Is it T, or X? XFMR? I never can decide.)

I forget, does \$\dfrac{Math}{Jax}\$ work in chat? Guess we'll find out. :)

@rdtsc no,haha, it's listing/labeling in the UL sense :)

Oh, yikes. I don't even have anything comical to say about that. Good luck! :)

Lizard, your question might do well on the Home Improvement site, chances are good someone has calculated it before. I have a formula which might be a starting point, but seems that MathJax isn't supported in chat.

Ok so I answered his question. MathJax wasn't supported there either. It is so useful, should be supported on all stacks!

@rdtsc Hmm, that may work, thanks.

@rdtsc Thanks for answering. MathJax is supported on Computer Science Are you sure you did use $$ instead of [] or something? I can also edit the MathJax in for you

@ThePhoton . .Regarding the question on 25000 volt fuse,the fuse holder would have been interesting.

hey there @Marla

@Shalvenay . . good afternoon

@Marla how're things going?

@Marla yeah, I suspect that fuse would live within some piece of MV switchgear that'd provide disconnecting and whatnot

Beautiful weather. 50 degrees.

The fuse holders on the poles are interesting. How they fail with a visible clue. (Hanging down)

Utility poles

@Marla they are kinda neat that way

Unfortunately I saw quite a few of those blown fuses. When testing a 1000 kW machine, sometimes it happens. Even when you have a built in 2000 A circuit breaker.

When the technicians set the breaker settings wrong.

eheheh

@Marla I've never worked with voltages above 1 kV at currents above ~1 mA. The kind of source you use for that kind of thing is generally so limited in power output that there's no need for a fuse.

I wonder what that OP was working on. I hope anybody who's dealing with 25 kV at any appreciable power doesn't have to ask questions about it on SE.

hey there @ThePhoton

@Shalvenay aye

@ThePhoton what's up? the inverter listing/labeling/UL cert business took a bit of a stranger turn, over here...

@Shalvenay Not much, slow day here

@ThePhoton so....it turns out that the one manufacturer of transfer-capable multimode inverters with switched neutrals is working on getting their inverters listed/labeled to UL 1741 (and is quite well along in that process, even)

If only I knew what a "transfer-capable multimode inverter" was

however, the test lab that's doing the listing and labeling is accredited by the Standards Council of Canada, and has been for over a decade....but is not accredited by OSHA (under the NRTL program)

@ThePhoton ah -- it's a solar inverter/battery charger combo that can run either standalone or as a grid-tied inverter, and can switch its "grid" input between multiple AC sources

(examples include the Outback Radian series, the Schneider Conext XW, and the Victron Quattro)

@Shalvenay Sorry, and why do you need a NRTL mark on this? Like do you need it to maintain your insurance coverage? Or to get your installation approved by your building inspector?

@ThePhoton NEC requires solar inverters to be listed/labeled (690.4(B))

(technically, field eval is an option, but you might be able to get a ride on the American Orient Express for the price of a field eval....)

Mm, Is a CSA mark acceptable? (And can they get one with their Canadian-approved lab?

@ThePhoton CSA listing/labeling the thing would be acceptable, but that isn't the case here

Well, Trump wins this one. Better get a home coal-fired generator instead.

the lab is in and of themselves able to test, list, and label to both the UL and CSA standards, but I'm not sure if that listing holds in the US, as OSHA doesn't recognize them as a NRTL, and I would suspect most inspectors would defer to OSHA on that matter even if it isn't an installation where OSHA compliance is required

@ThePhoton LOL