RedBear MKX 50 Power Transformer

[Enzo]

As far as I can tell your English is flawless. I don't detect any culturalisms. ( I recall a guy who had great English - he was Russian - but he just couldn't remember to use articles. In Russian, you say "hand me book", while in English you say "Hand me the book." But we are very informal in our use as a rule, and any of those options would convey the meaning you intend.

Me, I do maintenance on a system, rather than to it. I do repairs to a system, not on it. WHy the difference? I have no idea.

I do testing of a system, rather than to or for it.

[Helmholtz]

Thanks Pete and Enzo!

I frequently use this online dictionary: https://dict.leo.org/german-english/...dShowSingle=on

Works in both directions and with many languages
The only thing I'm missing is typical examples with prepositions.

[pdf64]

...240V in North America is considered single phase. It goes back to the distribution network before the transformer on your local power pole.

Sorry, I'm just trying to make sense of the arrangements there; is it correct that the supply to the house is a neutral at ground potential, and 2 lives, which, with reference to neutral, are 120V fused at 30A or whatever, and are 180 degrees apart from each other? And perhaps a ground in urban areas?
If so, I don't understand why it gets officially called single phase? As the reality, which regard to neutral / ground, is that there it's 2 phase supply

As Helmholtz stated, the english terms for electrical distribution phase throw a wrench in the works.
....

I'm not trying to be argumentative, honest, but with regard to the phase terminology, I don't see what the confusion / issue is?

[Enzo]

The power coming down the wires from the power company are typically a single hot wire at high voltage , with a ground. That feeds a transformer on a pole outside my home. The transformer then sends a center tapped 240v into my house. The center tap is then bonded to the earth ground in my home, resulting in the opposing phase 120v circuits for distribution within my house.

Industrial power is often send in three phase three wire from the plant. Then we can get into the whole delta or wye stuff.

[Helmholtz]

Means that it's actually a 2-phase supply and you could use a 2-phase- full wave rectifier to get up to 170VDC - provided local EMC regulation allows for such low power factor loads.

[pdf64]

… Then we can get into the whole delta or wye stuff.

I suppose that by the same principle, equipment could utilise a live neutral 120V feed or a live 1 to live 2 240V feed? eg as a soft start for motors, low power mode etc.

[Enzo]

Means that it's actually a 2-phase supply and you could use a 2-phase- full wave rectifier to get up to 170VDC

I guess that depends upon your frame of reference. Power comes to my home on a single wire. It is only after leaving my transformer it is split. I liken it to a guitar amp. A single 120VAC comes into my amp, but only after the transformer do I get multiple windings and phases.

And I guess phases context changes. Power distribution versus power supplies in circuits.

[Helmholtz]

Power comes to my home on a single wire.

That's actually impossible. You need a return wire/conductor for a current to flow.
I think you mean a single phase supply.

It is only after leaving my transformer it is split. A single 120VAC comes into my amp, but only after the transformer do I get multiple windings and phases.

In both contexts phase refers to an AC voltage having a definite phase difference to another one.
In a 2-phase system the phase difference is 180°, in a 3-phase system it is 120° between the different phases.

A 2-phase (full wave) rectifier can be used with a 2-phase supply, no matter if the transformer which provides the 2 phases is outside or inside of some equipment (e.g. an amp).

[pdf64]

…Power comes to my home on a single wire. It is only after leaving my transformer it is split...

That’s interesting, I had no idea that a monster mains supply transformer might be on the user’s site.
Is it your’s, or the electricity distribution company’s?
Is the feed to your home 240 or 120V? 240V seems to be more logical.
Apologies for the derail

[J M Fahey]

"Single wire" may mean the return is ground, ACTUAL ground/dirt.
Very common to save copper.

On the other side, AFAIK US "home 240V" comes from a grounded center tapped 120+120VAC transformer, so you both have 120V to neutral/Ground using 1 of the HOT wires and 240V Hot to Hot, no neutral/Ground involved.
Which of course is acceptable for ovens, Air conditioning, water pumps and any other heavy loads, not for your TV , electric shaver or other smaller appliances.

While I guess UK uses 240V (nominal) from a single Hot wire to Ground.

So 2 different flavours of 240V

FWIW we use the old European standard (which is perfectly fine) of 3 x 380V 3 phase + neutral system ; 220V phase to ground, 380V phase to phase .

Here Phase means displaced 120 degrees from each other, not US 180 degrees out of phase.

I had no idea that a monster mains supply transformer might be on the user’s site.

Not "monster" , I guess itīs a few kW pole mounted transformer, feeding a few houses in that street.

[g1]

Like Juan said, the 'ground wire' can be just the dirt. The transformer here is on a pole outside our house, as we are rural. I believe in urban centers they may have more than one house per transformer. And it is 240V coming into the house. It gets split up in the breaker box, though some things run on 240 like oven and clothes dryer. Part of the electician's training involves making sure the loading of the two 120V 'sides' is somewhat balanced.

with regard to the phase terminology, I don't see what the confusion / issue is?

Because 'single-phase and '3-phase' are fairly common terms with regard to the electrical utilities. So if I google 'single-phase rectifier', I will see both types of 'full-wave' circuits being discussed here (and not half-wave rectifiers).

[Enzo]

In the USA, the high voltage distribution wire comes pole to pole.. There can be a return neutral wire, but especially in rural distribution, the earth itself is sometimes the return. So one wire. In rural settings, typically each home has a transformer on a pole outside stepping the kilovolts down to the 240CT that runs into the house. In the suburbs or other dense areas, a somewhat larger pole transformer can be used to power several homes as mentioned above.

Seems to me the transformer on my pole was a 100kVA size.

[Delta362]

Got the amp finished. The chassis actually had a cutout for a larger PT as well as two additional power tube sockets, so it appears the larger PT could have fit without issue. I ended up having to make an adapter plate to mount the PT. Got it installed, along with the PT, redid the power supply wiring that was modified by someone else, added balancing resistors on the first stage of caps, and added a humdinger circuit. Cleaned the electronics, installed and biased an older set of customer provided power tubes. It's ready to go.

Thank you for all the help!