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The 500k-ton typo: Why data center copper math doesn't add up

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Re: The 500k-ton typo: Why data center copper math doesn't add up

#121

Post by knollimar »

amluto wrote: post #117
knollimar wrote: post #77

Earlier quoted context omitted.

This isn't true at all unless you narrowly dwfine "the entire system". Each feeder can be aluminum if you put special goop on any copper connections. Breakers accept it just fine, etc. You should avoid it for smaller wiring, though. There's special 8000 series aluminum if you're trying to be serious with Al feeders

The goop is generally considered to be unnecessary. What you need is a termination that is rated for aluminum wire, and these are very, very common as long as the wire in question is fairly large (8AWG or so and larger).

I only put it in the comment since the commenters here seemed uninformed.

It's better to be safe and follow specs; it's more when you're doing some compound splice where it makes sense. I figure it'll make more people feel easy about it if there's a preventative measure

Re: The 500k-ton typo: Why data center copper math doesn't add up

#122

Post by Jblx2 »

kergonath wrote: post #90
potato3732842 wrote: post #40

Earlier quoted context omitted.

It's almost always the engineers, analysts and MBA spreadsheet pushers and other people removed from the physical consequences outputting these mistakes because it's way easier to not notice a misplaced decimal or incorrect value when you deal in pure numbers and know what they "should" be than you are the person actually figuring out how to make it happen the difference between needing 26666666.667 and 266666666.667…

Around here, asking "does this number make sense?" when coming across a figure is second nature, reinforced since early in engineering school. The couple of engineers from the US that I know behave similarly, which makes sense because when your job is to solve practical problems and design stuff, precision matters. > difference between needing 26666666.667 and 266666666.667 of is pretty meaningful To be fair, that’s…

>why we’d use 2.6666666667e7 and 2.66666666667e8

Engineers prefer (wait for it) "Engineering Notation": 26.67e6 and 266.7e6.

https://en.wikipedia.org/wiki/Engineering_notation

Re: The 500k-ton typo: Why data center copper math doesn't add up

#123

Post by quickthrowman »

matthewaveryusa wrote: post #84
Fiveplus wrote: post #30

The funniest part is beyond the typo, the complete lack of physical intuition from the analysts who circulated this. 500,000 tons is roughly the weight of 1.5 Empire State buildings. If your rack busbars weigh more than the structural steel of the facility housing them, you have a geotechnical engineering crisis on your hands. It is wild that we reached a point where financial modeling is so decoupled from physical r…

Just to make it even more real: During covid I added a sub-panel and the wire (more like the sausage given the girth) between the sub-panel and main panel was aluminum because of cost. You just need to be a tad careful at the connection points with copper -- nothing a caring literate person can't handle

Did you use antioxidant paste on all of the aluminum terminations? If you didn’t, please pay an electrician to come fix it. If you did apply the paste, you are in the 0.01% of non-idiot non-electrician homeowners and can skip my rant about homeowners doing electrical work in the next paragraph. I sell electrical work and have seen some incredibly poor work done by homeowners.

Do not install aluminum wire if you are a homeowner unless you already know enough to use antioxidant paste and also to use a torque screwdriver or torque wrench for terminations and know where to find the torque values for the wiring devices you are using. If you don’t apply the paste, the surface of the aluminum will oxidize and could catch fire due to increased resistance.

I suggest not even touching copper as a homeowner, but it’s your choice and your house.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#124

Post by lazide »

viggity wrote: post #107
Fiveplus wrote: post #30

The funniest part is beyond the typo, the complete lack of physical intuition from the analysts who circulated this. 500,000 tons is roughly the weight of 1.5 Empire State buildings. If your rack busbars weigh more than the structural steel of the facility housing them, you have a geotechnical engineering crisis on your hands. It is wild that we reached a point where financial modeling is so decoupled from physical r…

Kinda like when someone said that instead of running for mayor, Bloomberg could have given everyone in the country $1M. A guest said it on NBC and Bryan Williams, nor the pundit had any intuition that it seemed grossly wrong. https://www.politifact.com/factchecks/2020/mar/06/msnbc/bad-...

The system incentivizes ‘sounds good’ over ‘is correct’.

If news agencies needed to pay out fines for false info, you better believe they’d be checking more.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#125

Post by quesera »

Jblx2 wrote: post #119
quesera wrote: post #103

Earlier quoted context omitted.

Only true for lighting circuits though, and most household circuits are mixed. The quantity and (edit: aggregate ) power draw of modern appliances is far greater now than 60 years ago, so the overall load on the old wires is much higher.

> power draw of modern appliances Here's a article that claims that refrigerator energy efficiency has improved dramatically from 1972 to 2012. https://appliance-standards.org/blog/how-your-refrigerator-h... I'd bet that modern TVs are more efficient that CRT televisions. Do most people even have desktop computers anymore, or have they mostly been replaced by laptops, tables, and phones? I'd be interested to see the…

These are good points, but having worked on a few older houses, I usually see overextended and overloaded circuits, not the opposite.

Standard small-house service used to be 60A, sometimes as few as 4 circuits! It's now 100A minimum by code, with 200A common.

Ovens/ranges have gone from 30A to 50A (dedicated) circuits by code. Microwaves also require dedicated circuits now. Gaming computers with big GPUs are common. Air fryers and electric pressure cookers are newly-common countertop appliances. People definitely use resistive electric space heaters more now (very cheap, much safer than the older options). And there's a trend away from gas and to electric ranges and water heaters. Heat pumps are also increasingly common. You mentioned air conditioners and EV chargers. Kitchens and bathrooms are now required to have dedicated (and GFCI) circuits. Household sizes are smaller, but houses are larger.

So I guess I'd say that, properly expanded, individual circuits should carry less current than they used to. But very often, appliances (AC, microwave, gaming rig, air fryers), are just "plugged in" to an unexpanded system, with varying results.

If you're lucky, they pop a breaker and you call an electrician. If you're not lucky, they push the power draw into uncomfortable zones, esp for Al wire.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#126

Post by quickthrowman »

dzink wrote: post #36
crote wrote: post #27

With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…

You just have to not mix and match. If you mix them the two need special bonding at every single connector or they can cause arching and fires.

Most wiring device terminations and lugs are Al/Cu rated. You’re supposed to use specific fittings for splicing together aluminum and copper wire (specific WAGO lever nuts are UL listed for this purpose along with some others), I assume that’s what you meant.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#127

Post by NooneAtAll3 »

NoNotTheDuo wrote: post #74

Amazingly ironic that in an article about a typo, there is a typo. > "Tat sounds like the ultimate catalyst for the commodities market and copper has been hitting records." "Tat" should be "That", imo.

you should've made a typo as well, as per tradition

Re: The 500k-ton typo: Why data center copper math doesn't add up

#128

Post by quickthrowman »

y-curious wrote: post #37
crote wrote: post #27

With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…

I am not an electricity/wiring guy so maybe you can help me understand. I thought aluminum is dangerous to wire with because it is a fire hazard (I bought a home this year and this was a prominent warning in my reading). Is that because it needs to be done very carefully? I imagine most data centers would not mess with a fire risk on such a scale.

If you apply antioxidant paste, torque the terminations to the correct value, and use wiring devices rated for Cu and Al conductors, there are zero problems.

Most homeowners know none of the requirements of aluminum wire installation so I don’t recommend using it, oxidation is bad and can cause fires. Just pay for copper NM cable, it’s dirt cheap anyways.

FWIW I sell and run electrical work for a living. I assume crote and amluto work in the electrical industry, since they’re the only other posters in this discussion who know what they’re talking about.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#129

Post by Jblx2 »

quesera wrote: post #125
Jblx2 wrote: post #119

Earlier quoted context omitted.

> power draw of modern appliances Here's a article that claims that refrigerator energy efficiency has improved dramatically from 1972 to 2012. https://appliance-standards.org/blog/how-your-refrigerator-h... I'd bet that modern TVs are more efficient that CRT televisions. Do most people even have desktop computers anymore, or have they mostly been replaced by laptops, tables, and phones? I'd be interested to see the…

These are good points, but having worked on a few older houses, I usually see overextended and overloaded circuits, not the opposite. Standard small-house service used to be 60A, sometimes as few as 4 circuits! It's now 100A minimum by code, with 200A common. Ovens/ranges have gone from 30A to 50A (dedicated) circuits by code. Microwaves also require dedicated circuits now. Gaming computers with big GPUs are common.…

>Gaming computers with big GPUs are common.

Is there a good way to quantify this?

Re: The 500k-ton typo: Why data center copper math doesn't add up

#130

Post by quesera »

Jblx2 wrote: post #129
quesera wrote: post #125

Earlier quoted context omitted.

These are good points, but having worked on a few older houses, I usually see overextended and overloaded circuits, not the opposite. Standard small-house service used to be 60A, sometimes as few as 4 circuits! It's now 100A minimum by code, with 200A common. Ovens/ranges have gone from 30A to 50A (dedicated) circuits by code. Microwaves also require dedicated circuits now. Gaming computers with big GPUs are common.…

>Gaming computers with big GPUs are common. Is there a good way to quantify this?

My best guess would be the size of the GPU market, before the AI crush.

I don't track that market (not a gamer), but it seemed substantial enough that I was aware of it. I do travel in geeky circles though.

Also, plasma TVs were big for a decade or so, and they run hotter than the CRTs that preceded them, or the LCDs/etc of today.

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