# Origin of term: Edison Connector?



## rsmentele (Mar 29, 2013)

My coworkers and I have been debating the slang term used for a NEMA 5 AC connector. Most industry people refer to them as 'Edison' connectors, and we have been debating whether the name comes because Edison invented the design, or if they mistakenly attributed Edison for the invention of AC. But even then, why call only the NEMA 5 an 'Edison'. 

I did a quick Google and Controlbooth search and didn't find much to answer the question. My thought is that if the name is referring to the inventor, then that is incorrect... From what I have found, Edison had nothing to do with the invention of the AC plug and socket. 

Im not sure if this is a question that can be answered, but its interesting.


----------



## sk8rsdad (Mar 29, 2013)

I wonder if the use of Edison evolved from the name of the electric company that provided the power.

In my neck of the woods the electrical generating company is called Hydro One, formerly Ontario Hydro, which was likely shortened from Ontario Hydro-Electric Generating or some such long ago. _Hydro _means _water_ or _liquid_. Yet everybody calls the hydro company when the electricity goes out.

Water accounts for only 22% of the electrical generation in Ontario. I guess _Nuclear One_ or _Gas One_ didn't appeal to the marketing department.


----------



## tyler.martin (Mar 29, 2013)

I tend to hear U-Ground just as often as Edison, Generally only see U shaped ground plugs on Hospital Grade plugs. 

I would agree though, the plug name probably game from the generating company, perhaps once upon a time, the plug type would have been proprietary to the service provider.


----------



## derekleffew (Mar 29, 2013)

My hypothesis:
The parallel blade, U-ground "Edison" began as an entertainment industry-specific term to distinguish from "Bates". It _should_ have been "Hubbell", but that term had already become synonymous with "Twist-lock".

Remember that it wasn't until the early 1960s that stage lighting connectors became grounded. If we knew when the term "Edison" first began being used to denote "parallel blade", we'd have a better explanation of its origin.
.


----------



## SteveB (Mar 29, 2013)

I have always wondered as well, where the term came from, as it truly and seemingly refers to nothing except old Thomas.

I don't believe any other industry refers to it as an Edison (maybe film a and TV), or at least I've never heard it spoken of. I would venture that the theatrical end (and not the film end) of the entertainment business has very few actual plugs and connectors we have traditionally dealt with, pretty much pin, Edison and TwistLoks and then only when we had to and that was often thought of as a "educational" connector. 

"Real" electricians (trade/contractors) tend to deal with a lot more variety of connectors and as such probably never called them Edisons. 

Film folks use a lot different stuff, though have tended more recently to move away from stage plugs and Trico's and as with the theatrical segment, now see a lot of different locking - L5-20. L6-20, PowerCon, etc... 

If I had to guess, I'd say that the "Edison" term came from the film business.


----------



## JD (Mar 29, 2013)

Started in the NY area through provider now know as "Con-Edison" (Consolidated Edison was a number of companies that merged.) I will try to look for the source story but it has been many years. Of course there is complete irony in it as Edison was dead set against AC power. From what I remember about the story, it actually did get it's start in the theater industry, which stayed DC for many many years. If you were not plugging something into the stage power (usually a plate dimmer and a DC generator / motor generator in the basement) then you were plugging it into an Edison sourced (AC) power plug, which of course was different than the "Stage Plugs" back in the early day. So, the name shortened and you were plugging into an "Edison." 

I am thinking the source was "Scene Design and Stage Lighting" by W. Oren Parker, 1974 edition. Just not willing to sit down and read the whole book again


----------



## MPowers (Mar 29, 2013)

JD said:


> Started in the NY area.............I am thinking the source was "Scene Design and Stage Lighting" by W. Oren Parker, 1974 edition.........



Not sure about the first, the second might be on track, though as a secondary source rather than primary. When I first started in this business it was not a term used by anyone in my circle of work. I first recall hearing the term around '68-'70 when buying Century EdKoTron dimmers and trying to decide what kind of receptacles to get.


----------



## JD (Mar 29, 2013)

MPowers said:


> Not sure about the first, the second might be on track, though as a secondary source rather than primary. When I first started in this business it was not a term used by anyone in my circle of work. I first recall hearing the term around '68-'70 when buying Century EdKoTron dimmers and trying to decide what kind of receptacles to get.



Well, the book was where I believe I read the explanation. The term had been around for many decades before. I must admit, before I got into lighting in the late 60's, I had never heard it before. A plug was just a plug, and a receptacle was just a receptacle. Of course, until you get into the profession, there's no reason to differentiate other than a "two prong" or "three prong". (And three prongs were rare back then!)


----------



## WooferHound (Mar 31, 2013)

The film crews that I worked with called those connectors "Stingers" because the ground pin was so long.


----------



## gafftapegreenia (Mar 31, 2013)

In the A/V & Corporate world, often times any cable with a NEMA 5-15 end is refereed to as an " A/C Cable ". Small projectors, laptops, monitors, etc all need straight 120v 60hz constant A/C power. Often one will see multiple cases labeled "A/C Cable" and one can comfortably assume that case contains cable with 5-15 ends, even if other types of locking "AC" connectors are being used on the same job. Nothing like opening up a case labelled A/C Cable to be greeted by a rainbow of colors and anything but an SOOW cable.


And lets not forget, before NEMA there was a competing connector to the 5-15 with both blades turned 90 degrees (like a 6-15), and of course no ground. Thus, some older houses have outlets designed for both styles, with two sideways T shaped slots in the receptacles, and no ground pin.


----------



## DMXpro (Mar 31, 2013)

JD said:


> ....I am thinking the source was "Scene Design and Stage Lighting" by W. Oren Parker, 1974 edition. Just not willing to sit down and read the whole book again



I have the 2008 edition, might it be there as well?


----------



## derekleffew (Apr 1, 2013)

DMXpro said:


> I have the 2008 edition, might it be there as well?


Although the 1979 edition does discuss the use of DC electricity in theatres, it makes no mention of a specific "Edison" connector. I'm pretty sure the current versions have relegated dimmer, resistance to a footnote at best.
.


----------



## DMXpro (Apr 1, 2013)

derekleffew said:


> Although the 1979 edition does discuss the use of DC electricity in theatres, it makes no mention of a specific "Edison" connector. I'm pretty sure the current versions have relegated dimmer, resistance to a footnote at best.
> .



As an aside, my edition actually has a whole page explaining resistance dimmers. However, this is the only context I could find that referenced the Edison connector:

"Ordinary household plugs with parallel blades, sometimes called 'Edison' plugs, are occasionally used in small facilities because they are inexpensive and readily available."
It makes no other mention as to why they're called Edison plugs.


----------



## gafftapegreenia (Apr 1, 2013)

DMXpro said:


> "Ordinary household plugs with parallel blades, sometimes called 'Edison' plugs, are occasionally used in small facilities because they are inexpensive and readily available."
> .




I wish this myth of "Edison is inexpensive" would go away. Yes, an add-a-tap is dirt cheap. Yes, a NEMA 1-15P vacuum cleaner plug is cheap. However, a quality NEMA 5-15 is at least two times, if not three times as expensive as a standard 2P&G. Even the economy grade 5-15's are the same price as a 2P&G. Readily available? Heck yes. But cheaper, NO.


----------



## len (Apr 1, 2013)

gafftapegreenia said:


> I wish this myth of "Edison is inexpensive" would go away. Yes, an add-a-tap is dirt cheap. Yes, a NEMA 1-15P vacuum cleaner plug is cheap. However, a quality NEMA 5-15 is at least two times, if not three times as expensive as a standard 2P&G. Even the economy grade 5-15's are the same price as a 2P&G. Readily available? Heck yes. But cheaper, NO.



It's not more expensive if the other parts of your system are all edison. Or if you're in hotel ballrooms running on wall outlets, not a distro, etc. While a good 5-15 is expensive, having a bunch of 2P&G to edison converters can be more expensive, especially if you leave them back at the shop. 

Not every rule is true for every application.


----------



## gafftapegreenia (Apr 1, 2013)

len said:


> It's not more expensive if the other parts of your system are all edison. Or if you're in hotel ballrooms running on wall outlets, not a distro, etc. While a good 5-15 is expensive, having a bunch of 2P&G to edison converters can be more expensive, especially if you leave them back at the shop.
> 
> Not every rule is true for every application.



Please don't think I'm anti-Edison. It is certainly a connector with a purpose, especially as you described. My post was aimed more at "traditional" theatres and performance spaces that choose 5-15 over 2P&G.


----------



## JD (Apr 1, 2013)

derekleffew said:


> Although the 1979 edition does discuss the use of DC electricity in theatres, it makes no mention of a specific "Edison" connector. I'm pretty sure the current versions have relegated dimmer, resistance to a footnote at best.
> .



Thanks for doing the read.
My edition has a page or two about those newfangled electronic dimmers, but most of the text is about resistance plate dimmers, even noting the only sure way to assure compatibility in theaters is to use resistance dimmers.
What a difference a few years make!

Still can't recall the source of the "Edison", but I remember the article well as it described how a lot of these seemingly nonsensical industry miss-phrases came to be.


----------



## DMXpro (Apr 1, 2013)

gafftapegreenia said:


> I wish this myth of "Edison is inexpensive" would go away. Yes, an add-a-tap is dirt cheap. Yes, a NEMA 1-15P vacuum cleaner plug is cheap. However, a quality NEMA 5-15 is at least two times, if not three times as expensive as a standard 2P&G. Even the economy grade 5-15's are the same price as a 2P&G. Readily available? Heck yes. But cheaper, NO.


I agree. Every time I buy connectors, 2P&G has been cheaper than Edison pretty much 100% of the time. I won't buy twist-lock anymore (unless I absolutely have to), waaay too expensive.


----------



## gafftapegreenia (Apr 10, 2013)

So, this question of "why do we call it an Edison?" has been in the back of my head since this thread started. I have a hypothesis to offer.

It IS know fact that Edison patented the light bulb screw base connection system that has become the modern E26/E27. When Harvey Hubbell II invented his connection device in 1904, he patented a two part system. This consisted of an adapter for the light bulb socket ( pig nose ) and a parallel bladed connector. Hubbell's intention was to make a user proof system, as the other two dominate methods of tapping power for appliances of the day were bare screw terminals, or screw base shaped connectors.

So, with this two part system, Hubbell had now invented an "Edison adapter and plug", which over the years was possibly simplified to "Edison connector" as wall receptacles became common and the need for socket adapters decreased. Add 100 years of electrical evolution and end user amnesia, and here we are calling 1-15 and 5-15's "Edisons". A hypothesis only, but still, in my opinion, a possible theory and interesting history. IF anything, researching Hubbell's patents has given me a lot of respect for the man.


----------



## JD (Apr 10, 2013)

Would make sense. We know the base as an "Edison." The only missing part is that I never heard an outlet being called an "Edison" outside of Stage/Studio/Film industry. Walk into an electrical supply house and ask for an "Edison outlet" and they will tilt their head and look at you strange. Ask for a "Duplex outlet" and they will grab a NEMA 5-15 (or 5-20) and bring it to the counter. 

Theater is one of the few industries where if you ask for an extension cable you are likely to be handed something that would not plug into a NEMA 5-15, thus requiring an additional identifier such as "Edison extension cable." 

The only way to get to the bottom of this would be to go to an old library and select a number of books from various decades of publication, read through each one and look for the earliest reference to an outlet being called an "Edison Outlet." (One of the few times the matter cannot be solved on Google!)


----------



## gafftapegreenia (Apr 10, 2013)

JD said:


> Would make sense. We know the base as an "Edison." The only missing part is that I never heard an outlet being called an "Edison" outside of Stage/Studio/Film industry. Walk into an electrical supply house and ask for an "Edison outlet" and they will tilt their head and look at you strange. Ask for a "Duplex outlet" and they will grab a NEMA 5-15 (or 5-20) and bring it to the counter.
> 
> Theater is one of the few industries where if you ask for an extension cable you are likely to be handed something that would not plug into a NEMA 5-15, thus requiring an additional identifier such as "Edison extension cable."
> 
> The only way to get to the bottom of this would be to go to an old library and select a number of books from various decades of publication, read through each one and look for the earliest reference to an outlet being called an "Edison Outlet." (One of the few times the matter cannot be solved on Google!)



And that's the problem with my theory - only entertainment types call it that.

It's probably just as simple as someone didn't know what to call 5-15, so they arbitrarily decided to call it "Edison", and that stuck.


----------



## church (Apr 10, 2013)

sk8rsdad said:


> I wonder if the use of Edison evolved from the name of the electric company that provided the power.
> 
> In my neck of the woods the electrical generating company is called Hydro One, formerly Ontario Hydro, which was likely shortened from Ontario Hydro-Electric Generating or some such long ago. _Hydro _means _water_ or _liquid_. Yet everybody calls the hydro company when the electricity goes out.
> 
> Water accounts for only 22% of the electrical generation in Ontario. I guess _Nuclear One_ or _Gas One_ didn't appeal to the marketing department.



It used to be known as the Ontario Hydro Electric Commission. I have some fresnels that still have this on their approval stickers


----------

