DC at wall outlets, NYC, around 1963 iirc -- Surprise!

[soldar]

Damn it...  Yes you re right !!!!!!!!! I can't find them (images) either !!!!
I started my Apprenticeship at E.T.S.A. (Electricity Trust of South Australia) Sth Aust Power Authority.
I used to build them myself by hand, for use in Sub-Stations, and large switch-boards....
Unlike the VIDEO though, the actual 'snap-release' part was only like 2" long, at the very top of the
(say) 14" knife-switch main Blade. Purely to rapidly break the circuit/arc after the main blade opened.

If you look at the photos you will see the "snap release" parts are, as you say, a separate part which is only a fraction of the length of the blade. I think the video is only meant to illustrate how the thing snaps back, not drawn to scale.

[Seekonk]

DC sockets will be the future.  Some big players are working on a standard to supply power for many small devices that are DC operated anyway. Power factor for these devices is driving the utilities nuts. Solar is also a big driver for this.

The first AC standard was 167Hz.

[NiHaoMike]

There's already a 12V "standard" that a lot of small network devices use.

[tooki]

Why change to DC at the enormous cost required to essentially rebuild the entire power infrastructure??

It's easier to change AC to DC than the other way around. In a data center, there's considerable efficiency gain to do it at a centralized device, eliminating losses with a distributed PFC architecture.
https://en.wikipedia.org/wiki/Rectifier#Twelve-pulse_bridge

Stop moving the goalpost. We were talking about power at the grid level. And by “change”, I didn’t mean rectifying the power, I meant converting the grid, since that’s what we were talking about

[NiHaoMike]

Stop moving the goalpost. We were talking about power at the grid level. And by “change”, I didn’t mean rectifying the power, I meant converting the grid, since that’s what we were talking about

There's no need to change the whole grid to DC in order to get some benefits of DC. As shown in the link, if power factor matters, it's a lot more efficient to rectify AC for DC distribution at the building level than it is to have individual active PFC rectifiers on every major load. It makes even more sense if there's a desire to integrate battery backup and renewable energy on site.

[tooki]

Stop moving the goalpost. We were talking about power at the grid level. And by “change”, I didn’t mean rectifying the power, I meant converting the grid, since that’s what we were talking about

There's no need to change the whole grid to DC in order to get some benefits of DC. As shown in the link, if power factor matters, it's a lot more efficient to rectify AC for DC distribution at the building level than it is to have individual active PFC rectifiers on every major load. It makes even more sense if there's a desire to integrate battery backup and renewable energy on site.

The topic of this thread was DC at the grid level (especially as to why it fell out of favor). Internal DC buses surely make sense for many applications, but that’s not what the topic was... DC grids went away because of the difficulty in transforming it. AC allowed this easily, and could easily be converted to DC where needed.

[Nusa]

Stop moving the goalpost. We were talking about power at the grid level. And by “change”, I didn’t mean rectifying the power, I meant converting the grid, since that’s what we were talking about

There's no need to change the whole grid to DC in order to get some benefits of DC. As shown in the link, if power factor matters, it's a lot more efficient to rectify AC for DC distribution at the building level than it is to have individual active PFC rectifiers on every major load. It makes even more sense if there's a desire to integrate battery backup and renewable energy on site.

The topic of this thread was DC at the grid level (especially as to why it fell out of favor). Internal DC buses surely make sense for many applications, but that’s not what the topic was... DC grids went away because of the difficulty in transforming it. AC allowed this easily, and could easily be converted to DC where needed.

Although the specific example posted by the OP was technically NOT a grid-level issue. That hotel has a major DC power station in their sub-basement, which was still in use at the time of the example. I'm sure their primary reason for updating to grid-based AC was because they were out of sync with society and the rise of portable AC-only appliances that guests traveled with (of which there were very few prior to the 60's).

[tooki]

Stop moving the goalpost. We were talking about power at the grid level. And by “change”, I didn’t mean rectifying the power, I meant converting the grid, since that’s what we were talking about

There's no need to change the whole grid to DC in order to get some benefits of DC. As shown in the link, if power factor matters, it's a lot more efficient to rectify AC for DC distribution at the building level than it is to have individual active PFC rectifiers on every major load. It makes even more sense if there's a desire to integrate battery backup and renewable energy on site.

The topic of this thread was DC at the grid level (especially as to why it fell out of favor). Internal DC buses surely make sense for many applications, but that’s not what the topic was... DC grids went away because of the difficulty in transforming it. AC allowed this easily, and could easily be converted to DC where needed.

Although the specific example posted by the OP was technically NOT a grid-level issue. That hotel has a major DC power station in their sub-basement, which was still in use at the time of the example. I'm sure their primary reason for updating to grid-based AC was because they were out of sync with society and the rise of portable AC-only appliances that guests traveled with (of which there were very few prior to the 60's).

Umm, the issue was specifically an outlet that was a relic of the DC grid. How do you see that as NOT being a discussion of DC mains power?!?

[Nusa]

Stop moving the goalpost. We were talking about power at the grid level. And by “change”, I didn’t mean rectifying the power, I meant converting the grid, since that’s what we were talking about

There's no need to change the whole grid to DC in order to get some benefits of DC. As shown in the link, if power factor matters, it's a lot more efficient to rectify AC for DC distribution at the building level than it is to have individual active PFC rectifiers on every major load. It makes even more sense if there's a desire to integrate battery backup and renewable energy on site.

The topic of this thread was DC at the grid level (especially as to why it fell out of favor). Internal DC buses surely make sense for many applications, but that’s not what the topic was... DC grids went away because of the difficulty in transforming it. AC allowed this easily, and could easily be converted to DC where needed.

Although the specific example posted by the OP was technically NOT a grid-level issue. That hotel has a major DC power station in their sub-basement, which was still in use at the time of the example. I'm sure their primary reason for updating to grid-based AC was because they were out of sync with society and the rise of portable AC-only appliances that guests traveled with (of which there were very few prior to the 60's).

Umm, the issue was specifically an outlet that was a relic of the DC grid. How do you see that as NOT being a discussion of DC mains power?!?

Relic of the DC era, yes, but not of the grid. The New Yorker Hotel was built in 1929 with its own DC power plant in the sub-basement to be self-sufficient. One of their generators was diesel-powered, so they did not need expensive grid access for backup purposes when the steam system (which heated the building as well as powered it) was under maintenance.

That doesn't mean you can't discuss the DC grid of course. It just happens the example given by the original poster isn't part of it.

[Vtile]

Another of the weird idiosyncrasies of New York City's power distribution, is that live steam is still delivered to many buildings in Manhattan.  It is used for heating.

That is not unique to New York.  Part of Seattle also has steam heating.  Being ever practical, the Soviets even distributed steam from nuclear power plants in some cities.

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

Yes, in cold climate it is most energy efficient to produce combined heat and power, heat is steam/water and power is electricity. Example City of Helsinki do have approx. 840 miles of pipes (to point out the temperatures are low, only a bit over boiling point at open air. So no spectacular steam leaks as in NY).
 https://www.euroheat.org/knowledge-hub/case-studies/helsinkis-combined-district-heating-cooling/