Technical > Home Improvement > 240v twist lock plugs

240v twist lock plugs

Going out on a limb and saying they're 'used' on anything not considered a semi-permanent install, such as an electric dryer, or electric range. On those, the appliance is installed in front of the outlet so it is unlikely that anything will bump into / knock out the connection.

Wall outlets or any other location in a home / office would use the twist-lock outlets. Also, the twist-lock is more likely to be used by 'portable' 240v equipment like 6000va battery backups / welding equipment / etc.

I think anything much larger than 30/40a would have to be a hardwire, anyway..

reply to fifty nine
I know RVs have 50-amp 125/250V supply line receptacle and plugs that are not twist lock. I can't say officially either way, but along the same lines as Jahntassa, larger semi-permanent installs probably don't require it, while installations where the cord maybe would be tripped over or accidentally become unplugged it's recommended.

Even with a high current device that doesn't need hard wired, once you unplug it there isn't any current there so from a strict safety standpoint, the twist lock doesn't get you much in that regard.

reply to fifty nine
There are twist-lock plugs from 15A to 60A.

They are used most often with portable applications (generators, machinery on wheels etc.)

reply to cdru

reply to fifty nine
So there aren't any specific amperage requirements? Just a tripping hazard requirement?

Meaning basically that they're not required due to current, but rather because they may pose a tripping hazard.

I would not say tripping but more where the plugs may fall out due to moving equipment or vibration.

I don't think twist-lock are required specifically by code. There are other types used in similar applications (i.e screw-on type.) I would imagine the code would specify a plug/socket that can not be puled out on portable equipment.

Most are 220V where if the plug pulled part way out, you would lose one line and may damage equipment (especially 3-phase.)
--
Scott Henion

Embedded Systems Consultant,
SHDesigns home - DIY Welder

reply to fifty nine
There is no specific requirement in the Code requiring twist-lock plug/receptacles.

Nor is there an amperage requirement. TLs are available in a wide variety of amperage and voltage values.
--
The Truth is the foremost enemy of the State now.

reply to fifty nine
»www.hubbell-wiring.com/Press/PDF···9815.pdf

There's also additional types/styles of twistlock (see the PDF).

Most common that I see are 5-20 (120v/20a) 5-30, 6-20, 6-30 and 14-30.

I don't know of any requirement pertaining to amperage but I'm sure their are some "environmental" rules.

In practice, however, how many people have seen a 5-30? I've seen plenty of L5-30 but have NEVER seen a non twistlock counterpart - even though they exist. Same goes for a 6-30...I've only seen a welder with one once. Same goes for a 120/240 circuit - only 30a and 50a are common flatblade - although other varieties exist unless your using a dryer or stove your most likely to see a twistlock.

Also...once you get to 3phase your options are twistlock or possibly something proprietary...

reply to fifty nine
Your friend is full of shit.

reply to fcisler

reply to fcisler
Wait 'till you come across a 'Russellstoll' connector (mainly used for Heavy Duty / Harsh Environment applications): »www.powercabling.com/index_worki···toll.pdf

-Tursiops_G.
--
If You're Unsure, "RTFM"... If You're SURE, "RTFM" Anyway.

My welders came with Crouse Hinds ARKTITE connectors, 30 and 60A. Supposedly explosion proof.

Nearly fell over when I saw the price of the mating sockets. So, direct wired or 50A range plug. Sold the 30+ year old connectors for over $110 for the pair on ebay.

reply to fifty nine
We have a 60A 3 phase power distro at work (Student Union)...it uses a pin and sleeve (Hubbell) connector. Even though it technically does not lock, you would be hard pressed to knock the plug out. They are not the easiest to fix, and definitely are NOT cheap. We have Twistlocks on our 30A circuits, and regular Edisons on the 15A. All of the sound companies that come in use cables with Twistlocks on one end, and one or two duplex receptacles on the other.

reply to fifty nine
We had 30 A twist-lock plugs on our boat. We had two 120 V lines (3 conductor), but some boats had a single 240 V line (4 conductor). IIRC, we also had a Y adapter to go from the two 120 V twist locks to a single 240 V flat blade plug (like a dryer).

EDIT: At work, I think they use twist-locks for the 400 Hz outlets. Maybe that's just to prevent normal plugs from being used by mistake.

reply to nunya

reply to fifty nine
The locking coupling makes for a more reliable connection in commercial and industrial settings, where vibration or incidental impact could disconnect a non-locking connector.
Locking connectors are designed so the different voltages and current ratings can not be accidentally intermated