ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Lock-down Thread
by Bill Addiss - 02/27/21 01:16 PM
Northern Tool Recalls Powerhorse Generators
by Admin - 02/25/21 09:49 PM
You will never guess
by gfretwell - 02/25/21 07:48 PM
New tool
by SMOKEYBOB - 02/15/21 04:59 PM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
0 registered members (), 11 guests, and 19 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 3 1 2 3
Older twistlock and other odd receptacle #187981 07/15/09 10:17 PM
Joined: Apr 2007
Posts: 36
junkcollector Offline OP
Moderators, if you could move this to the electrical nostalgia section...Thanks.

I was rummaging through some old devices that I had lying around the other day and came across this older Hubbell Twistlock Receptacle. I've seen many of these installed in older buildings, and I'm assuming that this one predates the nema standard for locking devices. A modern NEMA L5-15 R has a little hook in on the ground slot so this one looked a little odd to me. It carries a dual voltage rating as well. (these are a little before my time)

[Linked Image from]
I got also a bunch of these single Hubbell (and some A-H)receptacles that have a really odd mount. They were in a box of really old electrical stuff at a garage sale. At first you would think that this could fit a raised cover with an opening for a single receptacle, however, the mounting tabs are about a 1/4" too small. I have no idea what these could have been used for, maybe some older plugmold type strip or something. (I have an "adjustment yoke" for a blank cover lying next to it for a gauge)

[Linked Image from]

[Linked Image from]

Tools for Electricians:
Re: Older twistlock and other odd receptacle [Re: junkcollector] #187985 07/15/09 11:37 PM
Joined: Sep 2002
Posts: 908
NORCAL Offline
If you were to take a locking type photocell & compare the configuration of it and the one in the top picture, they are the same, & the receptacle in 2nd pic. is a floorbox receptacle.

Re: Older twistlock and other odd receptacle [Re: NORCAL] #188039 07/17/09 11:20 PM
Joined: Mar 2004
Posts: 251
I have a box of those Twist loc rec. It is a non grounding type. They were common used during the late 1950 & 60's on fire apparatus. Used on fans & lights. They made a 2 conductor also. They were frequently miss wired as the screws on the early models were not identified. I was in a fire dept that used these. Several of the lights were mis-wired. When you started the generator on the pumper and stretched the cord to a light set on the (wet) ground, if you touched the truck, you got a tingle. One pole was grounded in the generator and the other on the light. Replaced them all with grounded and properly wired TL.

Re: Older twistlock and other odd receptacle [Re: WESTUPLACE] #188053 07/19/09 09:30 PM
Joined: Jul 2001
Posts: 599
JBD Offline
"Old style" (non-grounding) twist lock devices are still available from most manufacturers.

Re: Older twistlock and other odd receptacle [Re: JBD] #188423 08/07/09 08:31 PM
Joined: Nov 2008
Posts: 1
busbar Offline
New Member

Re the first picture—up to the early 1970s in northern California, these were used extensively on construction sites. At temporary power poles, typically there were a pair of these, one receptacle was labeled “110” and the other was labeled “220”. That way extension cords could be used for either voltage. (Never mind the hazards.)

This was at a time when CALOSHA was just comin’ up to steam, and inspectors were busy with site inspections and issuning citations.

Re: Older twistlock and other odd receptacle [Re: junkcollector] #188429 08/08/09 03:38 AM
Joined: Jul 2002
Posts: 8,379
Trumpy Offline
Good stuff,
Junk collector.
I fail to see however, how this is junk.

One thing I love about the older sockets and the like is the small designs used to adorn something like a receptacle.
Like the front face of the recept in your second picture, someone designed that, who I have no idea, but at the time that would have looked good.

To most people that is somewhere where you put your plug in to get something to work.

It's a shame that only electricians appreciate the work that went into these devices. frown

Re: Older twistlock and other odd receptacle [Re: Trumpy] #189807 10/26/09 02:16 AM
Joined: Nov 2002
Posts: 790
wa2ise Offline
[Linked Image from]
Here's an old outlet in my mom's place. Turns out Australian plugs will fit, and as this one is fed by 240VAC, the Australian plug would feel nearly at home. Except for the 60Hz, and that both current carrying pins (that's the slanted ones, the vertical one is the ground) are hot with 120VAC. In Australia, one is a neutral, and the hot is 240V 50Hz.

Re: Older twistlock and other odd receptacle [Re: wa2ise] #189828 10/26/09 08:47 PM
Joined: Apr 2007
Posts: 36
junkcollector Offline OP
That is a neat receptacle, Wa2ise. I've seen a few of those, but they were wired for 120. A hardware store near me still has the single version of that style, and the NEMA 10-20. I think they have plugs for each variety, too. I actually have an adaptor with that crowfoot pattern, so that you can plug the crowfoot into a standard receptacle.

Good stuff...

Re: Older twistlock and other odd receptacle [Re: junkcollector] #189857 10/28/09 08:07 AM
Joined: Feb 2002
Posts: 183
n1ist Offline
Back in my elementary school, we had crowsfoot for 110DC and regular for AC (or was it the other way around? Too long ago :-)

Re: Older twistlock and other odd receptacle [Re: n1ist] #189871 10/28/09 02:34 PM
Joined: May 2005
Posts: 984
ghost307 Offline
All our 120V stuff at Ford was fitted with a weird twist-lock pin-and-sleeve plug that fitted into matching weird receptacles.
I know that whacking off the plug of a new tool to install an oddball plug sounded dumb, but we stopped 'losing' electric drills and other small power hand tools almost immediately after the policy was adopted.

Page 1 of 3 1 2 3


2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Posts: 22
Joined: August 2009
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
275,539 Are you busy
209,439 Re: Forum
196,834 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3