Introduce 415/240 V as a standardized voltage

H

hokadof188

AI Enthusiast
Location
Paragui
Occupation
Retired medium tension insulator manufacturer
We are all seeing it in datacenters. It makes sense in offices and industry. In some cases, it's very easy to retrofit 277 by tapping the transformer low, though that usually falls to the utility.

Dare we offer it for residential consumption, like the majority of other developed nations?
 
hokadof188 said:
We are all seeing it in datacenters. It makes sense in offices and industry. In some cases, it's very easy to retrofit 277 by tapping the transformer low, though that usually falls to the utility.

Dare we offer it for residential consumption, like the majority of other developed nations?
Click to expand...
We're all seeing it? I haven't been in a DC yet where 208/120 wasn't the only option available, though I haven't had the chance to visit an Amazon, Microsoft, or Google-owned facility yet. But your profile says you're on the bottom half of the planet, and I'm on the top half, so maybe that has something to do with it?
 
I made the same post a while ago.

One other thing for those out west. In the rest of the world instead of having bare 12,000 volt wires down every country lane, they have one big central transformer and then distribute fairly long distances at 230/400. So less risk of fires from branches and such, low voltage.

Of course most existing global electronics and lighting can already run on 240.

Plus 240 volt kettles for the kitchen are like 3500 watts at 240, get your coffee and tea faster.
 
I think the 2026 NEC is adding 416Y/240 as a standard voltage for load calculations since it is being used some in commercial and industrial, but it wont be for residential. We'd be lucky if we can bump our ANSI voltage standard 208Y120 to 220Y127.
 
hokadof188 said:
We are all seeing it in datacenters. It makes sense in offices and industry. In some cases, it's very easy to retrofit 277 by tapping the transformer low, though that usually falls to the utility.

Dare we offer it for residential consumption, like the majority of other developed nations?
Click to expand...
In UK it was 415/240V 50 Hz. Now it is 400/230V 50Hz for almost all of Europe. The majority of the residences are just 230V 50Hz. Most of the projects I did was up 11kV.
 
Birken Vogt said:
That would only be one more standard added to the mix

120/208
127/220
120/240
240/416
277/480
347/600

Of course many of us are already running pretty close to 127/220 because the poco is always inching higher.
Click to expand...
I would not have both 208Y/120 and 220Y/127 I would just change it, do a coordinated change to all the North American standards at the same time NEC and ANSI C84, CSA, NOM like they did when it was 190Y/110 and we bumped it to 200Y/115.

No need to replace any existing equipment, anything rated for 208 most likely can work on 240.
The problem with bunping 120 to 127 would be 120V rated incandescent lighting and I am not sure what else?
Perhaps old tube tube equipment?
The benefits would be reduced voltage drop, instant energy savings,
and utilities that have always hated delta secondaries can phase out some 240 delta services with a wye 220.

You can still find 200Y/115 and even old 190Y/110 labeled equipment out there, its not like all the 208 stuff would need to be replaced, I think there was a thread a few years back showing a transformer in a theater building that was labeled 190Y/110
 
tortuga said:
The problem with bunping 120 to 127 would be 120V rated incandescent lighting and I am not sure what else?
Click to expand...
That's pretty much the only issue that I can think of, aside from some antique vacuum tube equipment. Perhaps the industry can shift to producing exclusively 130 V bulbs as are already somewhat commonly available, since there are a lot of regulatory changes going on with that anyhow. An alternative, could be a super small -12 V auto transformer for special lighting requirements.
 
When you have 1:2 ratio single phase split phase based system and 1:1.732 3ph wye systems in coexistence, you can't have the same "low" and "high" consumer voltages, so we end up with odd ball "secondary" consumer voltages in order to anchor down a legacy voltage to be retained, which is 120v. This dates back to electron tube radio sets and there was a time when houses only had 120v power.

208V is the result of the desire to maintain 120v single phase power availability for plug-in loads. If we default to 240v for the "high" voltage, we'll have 138v for the "low".

I believe 208Y/120 joined the game so lots and lots of single phase can be balanced across all three phases designed around 120v plug-ins and still be able to have three phase for restaurant walk-in and the shared elevator for 2-3 story professional plaza.

The one perk of 480/277 is that it is exactly 6/5 of 400Y/230, so it maintains the exact V/Hz ratio for motors. Not sure if that's relevant.

415Y/240 is a silly thing to implement today. This was/is a system in-use in England/Great Britain/United Kingdom places and rest of Europe 380Y/220 before they decide to harmonize to 400Y/230 and adjusting tolerances so it was formalized to 230.
 
Perhaps if UL or other regulators gave appliance manufacturers the next decade to make all new appliances rated for 100 - 250 V; it is more than possible with inverter drives and switching power supplies in everything now, then one day new builds can start to be 433Y/250 or 416Y/240 V.
 
Flicker Index said:
415Y/240 is a silly thing to implement today. This was/is a system in-use in England/Great Britain/United Kingdom places and rest of Europe 380Y/220 before they decide to harmonize to 400Y/230 and adjusting tolerances so it was formalized to 230.
Click to expand...
I dont know anything about other countries thats interesting! I always thought 416/240 wye was just for telephone company equipment in the 1980's and now datacenters that probably power this website.
Building would get some massive primary feed and make that voltage onsite as well as a massive amount of positive grounded DC. I love weird stuff like that.
 
I think some guidance for how to color-code voltages in the NEC, other than DC, 120/208V, 120/240V, and 277/480V, would be helpful, even just as an informational note.

I know color codes aren't mandatory, other than the few parts of color codes where it is (neutral, EGC, high leg). But it would be helpful to have some guidance on what to do if you have 600V coexisting with 277/480V, or 230/400V coexisting with 480V, instead of a patchwork system of every installer's inconsistent arbitrary decisions.

My recommendation:
All voltages <=250V: black/red/blue coloring (which the special exception of when orange is required)
All voltages > 250V: brown/orange/yellow coloring
Volts-to-neutral <= 250V, while the interphase voltage is >250V: use the old British code (red/yellow/blue), except with a gray neutral. The old British code adapts easiest to the NEC.
Use violet bands to tell apart multiple systems with the same color scheme, when coexisting on the same service. E.g. 600V would have violet bands on brown/orange/yellow, while 277/480V would be plain brown/orange/yellow.
 
If we are going to change the supply to buildings, we need to be looking at DC supplies and forget about changing the standard AC voltage.
 
You must log in or register to reply here.
Top