# 20a Crows foot receptacles



## Briancraig81

Were re-doing a bunch of dormitories at a local college, the building was built in 1966. Each entrance way (4 dorms per entrance) has one of those old 20a Crows foot receptacles in it. I know they could be 120 or 240 [These I haven't had time to test yet.]

Seeing these and knowing this building was built in the mid 60's has perked my interest a bit in them. I'm seen them before but never have known what plugged into them. Checking my copy of Old Electrical Wiring Maintenance and retrofit (1998), I though David Shapiro would have said more about them but all he basically said was nothing has been made in recent years that would plug into them and goes into detail about converting them to a standard receptacle. Looking at my 1947 GE Supply Catalog, they list single and duplex's, which leads me to believe whatever they were used for might have been an ordinary appliance being they made them in duplex's.

Any help to unravel this mystery is greatly appreciated.


----------



## oldtimer

Briancraig81 said:


> Were re-doing a bunch of dormitories at a local college, the building was built in 1966. Each entrance way (4 dorms per entrance) has one of those old 20a Crows foot receptacles in it. I know they could be 120 or 240 [These I haven't had time to test yet.]
> 
> Seeing these and knowing this building was built in the mid 60's has perked my interest a bit in them. I'm seen them before but never have known what plugged into them. Checking my copy of Old Electrical Wiring Maintenance and retrofit (1998), I though David Shapiro would have said more about them but all he basically said was nothing has been made in recent years that would plug into them and goes into detail about converting them to a standard receptacle. Looking at my 1947 GE Supply Catalog, they list single and duplex's, which leads me to believe whatever they were used for might have been an ordinary appliance being they made them in duplex's.
> 
> Any help to unravel this mystery is greatly appreciated.




Please post a picture of these odd receptacles!


----------



## wildleg

group fridge or oven ?


----------



## Wirenuting

Briancraig81 said:


> Were re-doing a bunch of dormitories at a local college, the building was built in 1966. Each entrance way (4 dorms per entrance) has one of those old 20a Crows foot receptacles in it. I know they could be 120 or 240 [These I haven't had time to test yet.]
> 
> Seeing these and knowing this building was built in the mid 60's has perked my interest a bit in them. I'm seen them before but never have known what plugged into them. Checking my copy of Old Electrical Wiring Maintenance and retrofit (1998), I though David Shapiro would have said more about them but all he basically said was nothing has been made in recent years that would plug into them and goes into detail about converting them to a standard receptacle. Looking at my 1947 GE Supply Catalog, they list single and duplex's, which leads me to believe whatever they were used for might have been an ordinary appliance being they made them in duplex's.
> 
> Any help to unravel this mystery is greatly appreciated.


I'll take a wild guess at what your talking about. 
If its like this pic, it was a golf cart battery charging receptacle. 

Post a pic of it or at least describe the pin configuration. It's probably a pre-NEMA outlet.


----------



## retiredsparktech

That recepticle refered to is a pre-nema 20a 230volt device. Why it's in the entrance way is anyone's guess. I saw that recepticle for a 60's model 18K btu 230 volt air conditioner.


----------



## TOOL_5150

Is this the receptacle yall are talking about?











I pulled this one out of a house built in the 70's and it was used for an air conditioner.


----------



## Dennis Alwon

Wirenuting said:


> I'll take a wild guess at what your talking about.
> If its like this pic, it was a golf cart battery charging receptacle.


Yes for DC. I wonder if they had golf carts there for some reason.


----------



## Briancraig81

It's exactly like the one in post #6.


----------



## Wirenuting

Briancraig81 said:


> It's exactly like the one in post #6.


Tool_5150 is the winner!!!!!


----------



## RePhase277

That is a non-grounding 120/240 V receptacle. It has two hots and a neutral. The only case I have ever seen them used was for thru-wall or window A/C units from the 60's and 70's. Apparently there was a fad where those units had 240 V compressors and 120 V fans and controls.

You can still buy those receptacles and cord caps at Ace Hardware and True Valu.


----------



## kbsparky

That is a NEMA 10-20R 120/240 Volt non-grounding.

It's also commonly found in Australia and New Zealand.


----------



## mbednarik

I see many of those installed around here in older all electric homes. The electric coop here used to wire these houses and install those outlets. Then the customer would buy a portable electric heater which had that cap on it. I would bet the college there used to have some portable heaters for the common area they would plug into those outlets.


----------



## Cujo

I took a picture of this a while ago to find out what this is. Found it in a school when the removed some old lockers. (was hidden behind)


----------



## kevink1955

In the 60's the school I attended had them in all hallways and used them for floor polishing machines, all terrazzo floors. Do not know what the voltage was, I was only 15 and confined my expermenting to lantern batterys.

They also had 2 slot singles that they used for microphones, later found the same config used on fire appratus for portable lights at 20A 125V rating.


----------



## cortez

InPhase277 said:


> That is a non-grounding 120/240 V receptacle. It has two hots and a neutral. The only case I have ever seen them used was for thru-wall or window A/C units from the 60's and 70's. Apparently there was a fad where those units had 240 V compressors and 120 V fans and controls.
> 
> You can still buy those receptacles and cord caps at Ace Hardware and True Valu.


The older air conditioners were hogs and needed dedicated circuits. Some are so hardy that they still run cool. I bet that the electric bill will buy a new unit in one year of usage *easy*.


----------



## user4818

kbsparky said:


> That is a NEMA 10-20R 120/240 Volt non-grounding.
> 
> It's also commonly found in Australia and New Zealand.


Does the NEMA crow foot have the same pin spacing in Aus/NZ?


----------



## kbsparky

AS far as I know. I went down there 34 years ago, with one in hand, and I seem to remember that it did fit.


----------



## varmit

Back in the day, these were common for air conditions and portable heaters. I have installed several when I was a "young 'un".


----------



## frenchelectrican

Peter D said:


> Does the NEMA crow foot have the same pin spacing in Aus/NZ?


 
It is still the same spacing.

( I have confirmed that details from one of my freind he live in NZ area so that is a fact. ) 

Merci,
Marc


----------



## frenchelectrican

This is a modern 15 amp 277 volt receptale I know it look simauir to the older crowfoot pattern.










Merci,
Marc


----------



## Aussielec

kbsparky said:


> That is a NEMA 10-20R 120/240 Volt non-grounding.
> 
> It's also commonly found in Australia and New Zealand.


Not sure what your talking when when you say "non-grounding"...but the left pin is your active, right is your neutral and the bottom is your earth... This is a standared Australian powerpoint...

The voltage to this would 240 volts active to neutral/earth... As far as two actives and a neutral go that is what we call a SWER distribution system and is only really used out in very rural area's of OZ...


----------



## RePhase277

Aussielec said:


> Not sure what your talking when when you say "non-grounding"...but the left pin is your active, right is your neutral and the bottom is your earth... This is a standared Australian powerpoint...
> 
> The voltage to this would 240 volts active to neutral/earth... As far as two actives and a neutral go that is what we call a SWER distribution system and is only really used out in very rural area's of OZ...


Non-grounding means there is no "earth" wire to the device. There would be two "active" wires with 240 V between them, and a neutral with 120 V between it and either "active".

We don't install non-grounding devices anymore, in general.


----------



## Aussielec

Seems like there's been some confusion on the Aussie powerpoints, they are NOT "non grounding" powerpoints, NO Aussie powerpoints of that shape will have 2 actives and neutral running to it without an earth. To the best of my knowledge Australia has never used such a device. We use what's known as the MEN earthing system which requires an earth cable to be run out to every powerpoint for the earthing system to function effectively. Rest assured if you plug any of your multi voltage equipment into one of our powerpoints you will release the magic smoke...


----------



## toklover

Aussielec said:


> Seems like there's been some confusion on the Aussie powerpoints, they are NOT "non grounding" powerpoints, NO Aussie powerpoints of that shape will have 2 actives and neutral running to it without an earth. To the best of my knowledge Australia has never used such a device. We use what's known as the MEN earthing system which requires an earth cable to be run out to every powerpoint for the earthing system to function effectively. Rest assured if you plug any of your multi voltage equipment into one of our powerpoints you will release the magic smoke...


 :lol::lol::lol::lol::lol:


----------



## MDShunk

I call that receptacle a "milk truck receptacle". I generally see it on older farms for the milk truck to plug into to pump out of the bulk tank. The newer configuration the farms use is a twist lock, but the milk truck drivers all carry an adapter to adapt to the older crow's foot configuration featured on older farms.


----------



## toklover

In Australia, that style of "receptacle", is the standard 1phase 10A outlet, then theres a 15A variant which has a slightly longer earth pin.










we do use other pin configurations, but those are reserved for various voltages other than 240V, and have to be labeled


----------



## RePhase277

Aussielec said:


> Seems like there's been some confusion on the Aussie powerpoints, they are NOT "non grounding" powerpoints, NO Aussie powerpoints of that shape will have 2 actives and neutral running to it without an earth. To the best of my knowledge Australia has never used such a device. We use what's known as the MEN earthing system which requires an earth cable to be run out to every powerpoint for the earthing system to function effectively. Rest assured if you plug any of your multi voltage equipment into one of our powerpoints you will release the magic smoke...


There were a instances in the past where our electrical code allowed for a circuit to be installed without a ground wire. Sometimes it was allowable to ground an appliance like a clothes dryer to the circuit neutral. This isn't allowed anymore. Circuits must contain a separate ground (earth).


----------

