20Amp Twist Lock connectors - outdated vs L6-20 and L6-15

Hello!

I am in the process of repairing fixtures and cables at a theatre that has not had much maintenance over the past decade. I discovered a discrepancy in the twist lock connectors when I tried to swap a new one from our stock with an existing one. The ground pin for the new plug was facing inwards and on the existing connectors, the ground pin was facing to the outside (See pictured, these are what are installed in the raceways and all breakout circuits).

I consulted my trusty backstage handbook, assuming someone just ordered the wrong ones. The arrangement of pins on the L6-15 matches the arrangement of pins on one of the 20A obsolete locking type receptacles, which leads me to believe the connectors installed in the theatre are obsolete. I have struggled to find information about this, but hope to get some answers here.

1. Is there a reason (other than inconvenience) that I would need to update all connectors to L6-20, assuming all are in good condition?
2. Why is this connector obsolete now? Is there a reason only one of the connectors pictured (L6-15) has the pin facing outwards? (just curious)

As of now, my plan is to use adapters between the L6-20 connector and the outdated ones for fixtures that have had their connectors updated.

Thanks!
 

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JohnD

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derekleffew

Resident Curmudgeon
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Premium Member
Your first picture of the yellow male is a non-NEMA 20A 125/250V TLGO (twist lock ground out). Not in any way compatible with any L6-xx. The "L" is for locking, the "6" indicates a 250V (hot hot grnd, no neutral).

BTW, you can't plug a TLGO into an L6-20. The non-NEMA has just a bump or nub on the ground pin, all modern ones have an actual bent blade.

Nor can one ever plug Locking 15 and 20 together. The 15 is smaller in diameter.

1. Is there a reason (other than inconvenience) that I would need to update all connectors to L6-20, assuming all are in good condition?
As said above, you don't want to update to L6-20.

2. Why is this connector obsolete now? Is there a reason only one of the connectors pictured (L6-15) has the pin facing outwards? (just curious)
Follow @JohnD 's link to read the other thread.

As of now, my plan is to use adapters between the L6-20 connector and the outdated ones for fixtures that have had their connectors updated.
Bad plan. Your choices are:
A. Update every connector in the venue to L5-20 (aka TLGI), or
B. Replace only failed existing connectors with new TLGO. While not NEMA nor UL, the other thread states these are permitted as replacements.
 
Last edited:

Gobokat

Active Member
Just wanted to chime in and point out a couple of quick summaries on this thread -
1) the "old" Hubbell twist-lock connectors are no longer acceptable because you cannot tell from the plug/receptacle which is 120V and which is 240V so you can guess the fun that could ensue.

2) be sure to use "L5" series if your supply is 120V, "L6" is for 240V supplies - the 2nd number set indicates operating current - so L5-15 is a 120V fixture drawing 15A max, L6-20 is a 240 volt fixture at 20A, and so on.
 

STEVETERRY

Well-Known Member
The core issue here is an old-type non-NEMA connector that allows use with H-N-G at 120V and H-H-G at 208 or 240V. As previously mentioned, one has no guarantee of the voltage on the connector.

It's legal, because it was legal when installed. However, if it was my facility, I would seriously consider updating to L5-20 and L6-20 depending on the voltage of the circuit.

Current 2020 NEC 406.4(F) says it all:

406.4(F) Noninterchangeable Types.
Receptacles connected to circuits that have different voltages, frequencies, or types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used on these circuits are not interchangeable.

ST
 

derekleffew

Resident Curmudgeon
Senior Team
Premium Member
Current 2020 NEC 406.4(F) says it all:
406.4(F) Noninterchangeable Types.
Receptacles connected to circuits that have different voltages, frequencies, or types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used on these circuits are not interchangeable.
So this connector is not permitted?

Stage Pin 20A 125V/15A 250V Male Plug
proxy.php

Another: https://www.lampline.com/general-connector-stage-pin-male
Leviton: https://www.leviton.com/en/docs/PK-93489-10-02-2A.pdf
Don't buy them from Walmart. They're out-of-stock anyway.
 

Jay Ashworth

Well-Known Member
The core issue here is an old-type non-NEMA connector that allows use with H-N-G at 120V and H-H-G at 208 or 240V. As previously mentioned, one has no guarantee of the voltage on the connector.

It's legal, because it was legal when installed. However, if it was my facility, I would seriously consider updating to L5-20 and L6-20 depending on the voltage of the circuit.

Current 2020 NEC 406.4(F) says it all:

406.4(F) Noninterchangeable Types.
Receptacles connected to circuits that have different voltages, frequencies, or types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used on these circuits are not interchangeable.

ST
Oh sure. But the odds are excellent he doesn't *own* the facility (and it's not residential anyway, which I think is also a requirement) so he'll have to *pay an electrician to do all of that receptacle replacement*, which may run up into 4 figures, depending on the size of the job. That isn't required, I don't think, just to build extension cords.
 

STEVETERRY

Well-Known Member

That is correct--this pin connector cannot be used at 250V in North America.

Please see this link:
ST
 

JohnD

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Gobokat

Active Member
A slight swerve to this issue, i.e. the Robe BMFL spot.

Yeah, was hoping no one was going to bring Neutrik into the thread - short answer is the PowerCon/True1/?? line from Neutrik is non-NEMA, so just like the old style twist lock, they are listed by the OEM as suitable for both 120 and 240 volt installation, but there is no way to tell, looking at a panel mount grey or a panel mount true1 if you're connecting to 120v or 240v (or 208v) source. Anyone who is running a mixed 120v-208/240v distribution how you indicate a 120v from a 240v supply with the powercon/True1 connectors? I guess the saving grace is that many of the devices with powercon inputs for their whips are voltage agile (i.e. smart power supplies) but what about companies which may be tempted to have True1 extension cables in inventory or make up some Grey/Blue cables?
 

STEVETERRY

Well-Known Member
Yeah, was hoping no one was going to bring Neutrik into the thread - short answer is the PowerCon/True1/?? line from Neutrik is non-NEMA, so just like the old style twist lock, they are listed by the OEM as suitable for both 120 and 240 volt installation, but there is no way to tell, looking at a panel mount grey or a panel mount true1 if you're connecting to 120v or 240v (or 208v) source. Anyone who is running a mixed 120v-208/240v distribution how you indicate a 120v from a 240v supply with the powercon/True1 connectors? I guess the saving grace is that many of the devices with powercon inputs for their whips are voltage agile (i.e. smart power supplies) but what about companies which may be tempted to have True1 extension cables in inventory or make up some Grey/Blue cables?

1. Open can.
2. Carefully re-insert worms into can.
3. Close can.

BTW, PowerCon and True1 are UL Recognized, not UL Listed--a big difference. For more on this subject, see:


:)

ST
 

RonaldBeal

Well-Known Member
How do you indicate 120/208/240 with IEC connectors? Same issue that doesn't seem to be an actua; issue.
 

STEVETERRY

Well-Known Member
How do you indicate 120/208/240 with IEC connectors? Same issue that doesn't seem to be an actua; issue.
The issue is where the connector is used. If it's on a piece of listed portable equipment, its UL recognition is subsumed in to the listing of the equipment. However, it cannot be used as a permanently installed receptacle in a building's infrastrucure, since there is not a physical configuration that guarantees a specific voltage. That makes it unsuitable for use as a general-purpose connector. On a portable system that is installed and configured by qualified personnel in occupancies covered by NEC article 520, you are right that this has not been a problem.

And watch this space for more developments--there is a change likely coming to the 2023 NEC that has passed the first revision phase that allows multiconnectors of 6 circuits or more to be used in the same facility at different voltages, even though they are intermateable. Again, use by qualified personnel is the caveat.

ST
 

tjrobb

Well-Known Member
IEC has a standard on this, 60320. Similar to NEMA standards, but global. Although it's not perfect- I bought a CPAP humidifier from Eastern Europe (don't ask) and was able to use an American plug by simply swapping the cord set; the machine side was the same.
 

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