strange receptacle

[John Arnold]

Anyone seen this type of receptacle outlet before?
Why the curved slots?

[John Kogel]

The curves are so you can rotate the plug to the right and lock it in place.
Maybe someone with telepathic powers here can tell you why this was installed. :D
I have seen versions of these receptacles on power cord extensions.

Probably for an AC unit.

[John Arnold]

Thanks. This is in a fairly old house, so I was thinking it must be some old, strange, obsolete design. Never saw one before.

[Michael Thomas]

Thanks!

Had not seen that chart before.

[H.G. Watson, Sr.]

Maybe someone with telepathic powers here can tell you why this was installed.:D

Bless your heart!

There is nothing which prohibits the use of twist lock receptacles for any reason. No one could say for what purpose or simple convenience, such as a hobbiest or whatever. The equipment being used may have been fitted with such a cord-cap - it is quite easy to replace a receptacle rather than void a warranty or listing and retrofit a new cord & cap for a device or appliance. The 2-blade variety indicates that no ground is present or that sufficient ground is not present (i.e. a 2-wire circuit is present (No ground) or a MWBC without ground. You may recall the earliest days when motorized lift-assist chairs were first being offered direct to the general public - originally ordered through health-care supply, required 8+ amps and options for 3-prong straight, 3-prong twist or 2-prong twist lock double insulated, cord & caps when ordering, and directions for dedicated 15-amp circuit or 20 amp non-dedicated circuit supply, for example.

Most often have come across 2-blade twist-lock receptacles (15A) at walls along floors in older (pre-60s, or even pre-1984ish undersized grounds) residential property, when an occupant at some point required long-term in-home life-supportive health care equipment (i.e. double insulated oxygen generation equipment, respirator equipment, suction pumps on 24/7 standby, and/or dialisis, with or without battery back-up), likely a switching power-supply on board the equipment.

Generally the short-term temporary use rental equipment is grounded 3-blade cord-caps or straight bladed "traditional", not twist lock and must be "attended" 24/7. (i.e. someone must be present to hear and attend/respond to an alarm or alert). The temp. equipment also tends to be much heavier and less mobile; Long-term and critical life support equipment in-home, generally twist lock cord caps. 2-bladed double-insulated likely since older home as referenced, equipment is multiply insulated, and isolated ground not often retrofit to non-healthcare facitily environment, and esp. not older home with obsolete wiring system.

If higher up installation and/or ceiling, another common use might include a mounted use item, such as mounted television, a wall hung fan appliance, etc.

You'll also find grounded twist lock receps in commercial and industrial environments where equipment is mounted above or mobile by one person equipment in worker hazard environments (i.e. overhead monitors in food service, janitorial "floor buffers", and so forth) or where gravity, vibration, movement, upon a cord cap (or the cord itself) would make it subject to withdrawl.

[Rick Cantrell]

Bless your heart!



As Scott said

"I would not suggest this unless you have a slight southern accent like I do! "

Maybe I'm wrong, but I just do not see you as an old Kentucky gentleman.

[Billy Stephens]

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Maybe someone with telepathic powers here can tell you why this was installed. :D
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HG to the Rescue. :rolleyes:
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[Garry Blankenship]

Great chart Robert. I did not change the receptacles, but in a effort to reduce my children's after school TV consumption, I put a male three wire twist-lock cord cap on the TV. The adaptor lived in my briefcase.

[Greg Weaver]

I'm an IT guy, and a lot of equipment optionally comes with twist lock plugs--particularly Uninterruptible Power Supplies (UPS) and switches/routers. It's possible he had a UPS set up if he was running a server, home security/video system, etc--something you don't want shutting down hard if there's a power outage.

You use twist locks to keep idiots from tripping over the cord and bringing down an entire site(or worse.) Or cleaning staff that figures it's no big deal if they unplug that computer nobody's using for a few minutes so they can vacuum.:eek:

[John Kogel]

You bring up a good point about that IT equipment but would you really want to run any of that stuff without a ground?
Right, good idea but for UPS it would most certainly be a 3 prong receptacle.

I believe the HO's electric crsytal ball may have been ungrounded and needed to be locked into the power grid. At least that's the vibration I'm getting. :D

[Greg Weaver]

You bring up a good point about that IT equipment but would you really want to run any of that stuff without a ground?

I realized after I posted that the ones he took photos of were ungrounded.


...Yeah, I got nothin'. :confused: