12A at 110V slow charging: 3% takes 7 hours

[EVer Hopeful]

What's in the hangar?

 

[skriefal]

There is no such thing as 110v/220v in the U.S., it's been 120v/240v for many, many, many decades now.

There does appear to be 110v at llamas's house .

But shouldn't be. The USA switched to 120v almost 60 years ago iirc. And to 117v before that.

 

[Tronguy]

Um. Saying this as a Telecom guy: You all would be amazed at the age of some of the older telecommunications equipment out there propping up Western Democracy or what-all. I'm as sure as sure can be that there's stuff built in the 1940's, out there somewhere, still running.. because it works, does the job, and isn't worth the trouble to rip out and replace with something cheaper/less power hungry/easier to maintain/whatever.

So, it wouldn't surprise me one single bit that somewheres-or-others there's installed power transformers up on poles somewheres delivering split-phase, 110/220 VAC to subscribers' houses.

My general understanding is that some of these last-mile transformers have taps on them that can be adjusted to compensate for long runs of copper, different input voltage, and so on; so, in theory, as standards change over time, some lineman in a truck can be sent to go out and adjust things. But, still. Maybe the older ones don't have that adjustment, and we're back to the it's-not-worth-the-trouble-time-and-money bit.

 

[skriefal]

I can believe that. And there's probably old vacuum tube equipment still serving important roles (not counting my stereo!) as long as it can be fixed. And 50-year old PDP-11 minicomputers in use at power plants and elsewhere. Some of these can be kept working for additional decades - or longer.

 

[Rocky_H]

My electrician friend had his theory that through the cumulative resistance of a series of connections, panels, wire lugs, wire through the house, outlet, plug, and cord into an appliance, that it's not surprising for a lot of end equipment to be seeing closer to 110V anyway, so that may be why the terminology lingers on.

 

[MY-Y]

In a hangar, your choices may be 208/120 if it has 3-phase power.

 

[Eric33432]

Um. Saying this as a Telecom guy: You all would be amazed at the age of some of the older telecommunications equipment out there propping up Western Democracy or what-all. I'm as sure as sure can be that there's stuff built in the 1940's, out there somewhere, still running.. because it works, does the job, and isn't worth the trouble to rip out and replace with something cheaper/less power hungry/easier to maintain/whatever.

So, it wouldn't surprise me one single bit that somewheres-or-others there's installed power transformers up on poles somewheres delivering split-phase, 110/220 VAC to subscribers' houses.

My general understanding is that some of these last-mile transformers have taps on them that can be adjusted to compensate for long runs of copper, different input voltage, and so on; so, in theory, as standards change over time, some lineman in a truck can be sent to go out and adjust things. But, still. Maybe the older ones don't have that adjustment, and we're back to the it's-not-worth-the-trouble-time-and-money bit.

They did not change the transformer ratios. What they changed over the years was the primary voltage leaving the substations.

One of the original distribution voltages, in use for over well over 100 years is the 2,400 volt system. Originally this distribution system was a 3 wire delta system and used 2,300 volts line to line, and used transformers with a coil ratio of 10:1 to deliver 115/230 volts to the service point and nominally 110/220 volts at the utilization point. Most of these systems were later changed to 2,400 volts, but used the same 10:1 transformers. Later many of these systems added a neutral wire, and increased the line to line voltage to 4,160. The line to neutral voltage was still 2,400 volts, and the old transformers were reconnected line to neutral. Not much of that is around any more except here and there in some really old downtown areas.

Another example, the distribution system the REA developed in the 1930's that is today the 7,200 volt system used to be 6,900 volts. Most were originally 3 wire delta, and most have been upgraded to 4 wire wye systems that are now 12,470 volts line to line, but still 7,200 line to neutral and still use the same 30:1 transformers connected line to neutral.

Some transformers are made with taps on the primary coil, usually taps at -5 -2.5, 0, +2.5 and +5 percent of the nominal voltage to adjust for the variations of distribution line voltage.

REA developed this higher voltage system using higher voltage due to the long and lightly loaded distribution lines in rural areas that could reach 30-40 miles long.

Here is a little info on that:

History of REA

 

[Eric33432]

Here is some detailed info about this transformer history, for those that want to nurd out:

https://www.eaton.com/content/dam/eaton/products/medium-voltage-power-distribution-control-systems/cooper-power-series-transformers/distribution-transformers-mineral-oil-immersed-self-cooled-60-hertz-voltages-and-connections-information-tc202001en.pdf