Notation used for power supply specification: 3Φ + E

[Julian Wayne]

In the job I'm currently working on, "380 V, 3Φ + E" is given as the
specification for a power supply voltage. (I'm assuming that's a
capital "phi" after the 3.)

Presumably the Φ means "phase". Would I be right in thinking that this
notation is not commonly used in English, and that it should be spelt
out?

Also, I'm guessing that the "E" stands for "earth". Again, would I be
right in thinking that this notation is not commonly used in English?

Any comments would be greatly appreciated.

Julian Wayne
Osaka, Japan

[大工]

Julian Wayne さんが 01:13 7/12/06 -0800 に書いたメッセージの件：

> Would I be right in thinking that this notation is not commonly used
> in English, and that it should be spelt out?

Hi Julian,

FWIW, i have seen and used the phi notation for "phase" since my childhood (and in more than one language), when i first became interested in things electric and electronic. I have also seen "E" for earth on many occasions (radios, etc.), but can't recall whether also in a context similar to yours.

> Also, I'm guessing that the "E" stands for "earth". Again, would I be
> right in thinking that this notation is not commonly used in English?

In the context you describe i would interpret the symbols as you do, and i think any engineer anywhere else would, too, although i don't think i would use "earth" myself in this context, but "neutral".

Not sure whether this was useful, but we try... :-)

Hendrik

--

* 南風言語業 *
http://www.paikaji-translation.com/

--

[Richard VanHouten]

The usual term is "3 Phase Y" in the electrical industry.

[Marc Adler]

On Dec 6, 2007 3:13 AM, Julian Wayne <cubu...@occn.zaq.ne.jp> wrote:

> Also, I'm guessing that the "E" stands for "earth". Again, would I be
> right in thinking that this notation is not commonly used in English?

You might check out this page:
http://en.wikipedia.org/wiki/Three-phase_electric_power

And specifically:
http://en.wikipedia.org/wiki/Three-phase_electric_power#Color_codes

--
Marc Adler
Austin, TX

Gauçac eztira multçutu, eta berretu behar mengoaric, eta premiaric gabe.

[Julian Wayne]

On Dec 6, 8:58 pm, Richard VanHouten <ric...@citlink.net> wrote:
> The usual term is "3 Phase Y" in the electrical industry.

Thanks. I hate to look a gift horse in the mouth, but I'm just curious
how you would go from "3Φ + E" to "3 Phase Y".

Julian

[Julian Wayne]

On Dec 6, 9:20 pm, "Marc Adler" <marc.ad...@gmail.com> wrote:
> And specifically:http://en.wikipedia.org/wiki/Three-phase_electric_power#Color_codes

Thanks for the link. It's given me a better idea of what's going on,
although I still can't quite see how the "+ E" fits into things.

Julian

[Richard VanHouten]

Quoting Julian Wayne <cubu...@occn.zaq.ne.jp>:

There are basically two ways a three-phase transformer can be wired:
with each leg connected to two of the phase outputs (a "Delta"
configuration - household power in the US usually takes one of these
legs and grounds the center, allowing either 120 volts from either
terminus to ground, or 240 volts across both termini), or with one end
of each leg bonded to the other two legs (this point may or may not be
grounded; this is referred to as a "Wye" configuration.)

See http://www.elec-toolbox.com/usefulinfo/xfmr-3ph.htm

[Richard VanHouten]

I work in the power industry, so I'm talking from my experience. The
Φ, as you surmised, stands for phase (a very common notation.)

The only way to provide a ground that is common between all three legs
of a three phase power source is in a Y (or Wye) configuration. (The
other possible way to wire a three-phase power source, a Delta, has no
neutral point that is the same voltage to each leg.)

It's possible that in that application, the ground lead is not meant
to carry current, in which case my assumption above that it is a 3
Phase Y (with grounded neutral) is faulty. That would be a 3 Phase
Delta plus ground.

Are there any diagrams accompanying this document?

Richard VanHouten

[Julian Wayne]

On Dec 7, 3:43 am, Richard VanHouten <ric...@citlink.net> wrote:
> Are there any diagrams accompanying this document?

Thanks very much for the explanation. I'm afraid that I have only been
given a small section to translate, and there are no diagrams or
anything else that might shed light on things.

I think I'm going to ask the client for confirmation. There are other
parts in the text that are a bit flaky.

Thanks again.

Julian