ECN Forum Forums Code Related Discussion NEC & other Code issues Heater-Fan-Lite Combos

Ah, thanks Bill.

For some reason I was thinking of big light/fan ceiling fixtures (i.e. those with exposed 36" diameter blades).

Not sure why I was going down that track - Evrything now suddenly makes sense!

Paul,

Just curious,
How did you envision Heat being an available option on one of those fans?

Bill

Thanks, Paul... I haven't laughed like that in weeks!

Yeah, I know, stupid foreigner!

I was envisaging some sort of circular heating element sandwiched between the central light(s) and the fan blades. I guess the "bathroom" bit should have given me a clue.... (Oh well, it's not been the best of weeks!)
*
[Pause while foot is extracted from mouth.]
*
I think I was being influenced by some ceiling fixtures here which have a center light around which is a circular heating element backed by a reflector. They're not very common these days, but they're often found as add-ons in very old unmodernized properties which have their main "facility" at the back door and otherwise unheated. Heating element was almost always 750W.

Bill:
To see what I mean, see TLC catalog pg. 116, item code TL GHL750.

Gee,
I thought I had supplied a way to connect these things, but all the Romex-Men don't want to carry 15' of M/C on their truck. I'm Mad, and they're lazy.

ZZZZZZZZ. . .Huh?. . .Wha. . .oh, it's not quitin' time yet. . . lemme sleep. . .ZZZZZZZZZZZZZ

bordew,
Do you know the origin of the edison term? Also, is a 4-wire multiwire ckt. called edison?
BTW,
Another advantage to on multi-wire ckts. is less voltage drop. And, more significantly, less conduit fill on raceway jobs.

Rojo-sy,

I think you'll find the "Edison" term for 3-wire comes from the early DC systems installed by the Edison Co. Grounded neutral conductor, one positive hot and one negative hot. Not sure about over there, but in the old 3-w DC systems here each hot line was called an "outer."

Redsy:
the term Edison 3-wire i learned about 35 years ago when I was an apprentice and it has stuck ever since.
It came originally from not sure, but in one of our appren text books was a piccture of a xfmr secondary with a center tap ergo edison 3-wire and was the term used by the instructor and it fit.
But Edison himself was a big fan of DC and his major competitor George Westinghouse was an AC proponent. Big debate bout the turn of the century, and it came down to an Execution of some murderer in NY as to use AC or DC for the kill, and it turned out they used AC and from what I remember it was decided to use AC.
I have heard 3-phase wye being called an edison but the definition just doesnt fit. Appropriately probably should be called a Westinghouse 3-wire.

Paul,
I think you have nailed it!
Most likely the term was developed from purchased power from the Edison Company which used DC systems, and before the Niagra Dam AC power Plant project by Tesla and Westinghouse proved AC's benefits - leading to the exclusive use of AC power systems.

As mentioned, Thomas Edison was reluctant to accept the use of AC, and promoted the use of DC. This probably was from envy and jealousness of Tesla's acceptance by Edison's rival, George Westinghouse!
Also, while Tesla worked for Edison Labs, he described the same thing about using AC instead of DC for system power, as he did to his Electrical Engineering Professor in College.
As what resulted from the MSEE Professor, Edison reacted the same way!
" Are You Crazy!!??, AC CAN NOT BE USED FOR ANYTHING PRACTACLE!!!"
[gee, I wonder if they were right? ]

Ok, enough with the Ancient History report

The term "Edison Circuit" may have been in some reference to circuits connected to Electro-Chemical cells.

The "Edison-Lelande" cell was a commonly used "Wet" cell, modeled from the famous "Leclanche Cell" experimental models.

The circuits made up in Edison Labs would have certainly included 3 wire DC circuits, made up by using two Edison Cells in Series, with a "Center Tap" between the two cells.
It's just a guess of mine that the term may have originated from this, but became familiar to the Edison Power Company's commonly used multiwire DC circuits.

FYI, and for more trivia , the 3 wire DC system can be derived from the following setups:

<OL TYPE=1>

[*] From two Cells connected in Series, "Center Tap" made between the Cells,

[*] From two Batteries connected in Series, "Center Tap" made between the Batteries,

[*] From One "3-wire" DC Generator, which has a "Center Tap" between two Field Coils,

[*] From two individual 2-wire DC Generators connected in Series, and a "Center Tap" made between the two Generators,

[*] From a "Combination" of a 2-wire DC Generator connected in Parallel with two Batteries or Cells, which are connected in Series with each other - and deriving the "Neutral" [proper term here!] from a "Center Tap" between the two Batteries or Cells.
</OL>

If these seem nearly impossible to invision, posted schematics can help unmask these obsolete systems.
I use the term "Obsolete" as to the extensive use of DC for consumer power systems [how the consumer buys Kilowatt Hours].
3-wire DC power supplies are far from being obsolete!
DC Power supplies for the PC you are using right now, have a 3-wire output.

Sorry to throw this DC stuff into a thread about Heater/Fan/Light combo's!
Just felt the urge again

Nurse Diesel Is Coming To Get Me!

Scott SET