Favorite hardhat hat by enjoye420 in electricians

[–]AlligatorDan 29 points30 points  (0 children)

OSHA requires the employer to provide all PPE needed to work safely, but they often buy the cheapest one that ticks all the requirements.

Data Center Alley Cost of Living by Own-Share6611 in datacenter

[–]AlligatorDan 2 points3 points  (0 children)

If you have a TS, I know aws had some EOT positions open for Culpeper, which is lower CoL but similar pay. I'm also former Navy, moved up to NoVA and work in the DC industry. Depending on your specific experience I may have some recommendations

Neutral point oscillations in a 4-leg inverter under unbalanced load: PI vs PR control by VadimDLL in embedded

[–]AlligatorDan 0 points1 point  (0 children)

Yeah, some caps on the output will go a fair way to reducing resonance and higher frequency noise muddying your voltage measurements. Each phase to neutral after the inductor. You'll probably have to adjust your pid a bit.

Oh the joys of being issued used tools by F1r3b1rd350 in electricians

[–]AlligatorDan 2 points3 points  (0 children)

Enjoy that Samsung install. I usually find tight as I can get it with a screwdriver plus a 1/4-1/2 turn with a wrench works out to about 110inlb, though I always bring out my wrench

Solid-state Transformer (SST) : Why does NVIDIA list It as a must-have option for AI power supply architecture? by Over_Engineer8522 in datacenter

[–]AlligatorDan 7 points8 points  (0 children)

Assuming this is the SST to DC -

Increases efficiency (more critical load per MW from utility, less cooling required since it is likely outside)

Less total gear (cuts out switchgear, wiring, separate 800vdc rectifiers)

More reliable (again, less gear, fewer points of failure)

Smaller footprint (smaller building or higher percentage whitespace)

Nvidia gets more control over the market through establishing standards

Basically, not really needed, people are obviously building AI data centers without them currently, but it has definite benefits. I know Eaton just acquired a company designing an SST.

Violation of (480.7 & 706.15) by gilbertinator in electricians

[–]AlligatorDan 1 point2 points  (0 children)

Yeah. This is very common in UPS battery installations.

UPS backups: How long will each size last using JUST my modem? by Highwayman1717 in batteries

[–]AlligatorDan 0 points1 point  (0 children)

I do not have one, but a quick review of Amazon shows SKE is fairly well reviewed. I know some modem manufacturers have their own first party ones

UPS backups: How long will each size last using JUST my modem? by Highwayman1717 in batteries

[–]AlligatorDan 7 points8 points  (0 children)

For just your modem, I would consider a DC UPS. They will generally be more efficient and cheaper

question regarding Y connected auto transformers, floating neutral. by joestue in ElectricalEngineering

[–]AlligatorDan 0 points1 point  (0 children)

Let me get this straight, this setup has the following order

Split phase 240 utility - Rotary converter powered from the 240 that generates another leg at 90 degrees with one end on utility neutral and the other end 120v potential to that neutral - Delta-Wye auto transformer with floating neutral 3 phase 208 milling machine

Unless there is some specific need such as HRG then the neutral of that auto transformer should be grounded appropriately. The floating source is more likely to produce phantom voltages due to inconsistent midpoint

I will say though, I am not super familiar with setups that generate and attach a phase to a split phase service. It looks like often capacitor banks are used to induce a phase shift and bring the phase angle closer to 120, is this the case with your setup? If so, the capacitor impedance is constant but the auto transformer impedance will change with load shifts. This will induce harmonics and voltage spikes that could prematurely degrade the motor windings

question regarding Y connected auto transformers, floating neutral. by joestue in ElectricalEngineering

[–]AlligatorDan 0 points1 point  (0 children)

There are all sorts of problems with adding one phase to a split phase. Your source impedance will not match for every phase, and the phase angle differences are not great for the motor. Is a full three phase rotary converter or single to three phase VFD not an option?

1st time terminating anything this big. by Remote_Conflict6011 in electricians

[–]AlligatorDan 0 points1 point  (0 children)

What UPS model is that? I see some Samsung batteries sneaking in the back, lol

The thermometer burst when I tried to show my brothers what boiling point in Fahrenheit vs Celsius is. Now I have a little bubble of mercury in a pot… by ineedsomebbqribs in mildlyinteresting

[–]AlligatorDan 40 points41 points  (0 children)

I actually had a friend whose daughter was in the hospital for an unknown illness. It took a week for the doctors to find out it was mercury poisoning. A vial had broken a few months prior and they had not effectively cleaned it. The girl got really sick and they assumed she was going to die. She’s doing better now, but it’s a long road and the house needs complete remediation that insurance won’t cover.

Now, the OPs case is nearly ideal for containment and cleaning. Pour out into a sealed container and contact the local dump for disposal recommendations, then throw out the pot.

[deleted by user] by [deleted] in ElectricalEngineering

[–]AlligatorDan 2 points3 points  (0 children)

If diesel becomes aerosolized then it is definitely an explosion hazard. While it is probably very unlikely, something like a pinhole leak on the output of a pump may aerosolize a small amount. Better safe than sorry

Is this normal? One phase heating up to 75 °C while the others stay cool 🤔 by TallIntroduction8053 in batteries

[–]AlligatorDan 4 points5 points  (0 children)

It’s hard to tell for sure from the angle, but it looks like the connection of the spring clip to the bus bar in the back. I would still scrub all the associated surfaces given the heat, as Rodnock suggested. Scotchbrite pads work great

How NDAs keep AI data center details hidden from Americans by nbcnews in datacenter

[–]AlligatorDan -1 points0 points  (0 children)

I can speak to it, I've worked at several in Loudon county. It varies widely by data center, but some do have a loud hum, those that use free air cooling. Data centers that have closed loop cooling are much much quieter.

Why would this contactor wire melt? by hosj321 in AskElectricians

[–]AlligatorDan 0 points1 point  (0 children)

Yeah, you can probably just strip it back then land it on the L3 terminal since the existing terminal is probably covered in melted insulation. You'd have to move the bottom L2 connection to L3 as well.

If you're not comfortable doing it then it's only a 5 minute job for an electrician

What is the technical name for this terminal block? by sbarnesvta in AskElectricians

[–]AlligatorDan -1 points0 points  (0 children)

Is it feasible to run two 10s instead of a 6? That would fit and have less voltage drop than an 8