L6-20 vs 6-15 for 220v

[Luis Oliveira]

Hi all,
I have a question I am hoping with an easy answer.

I notice that some machines say that you have to have a L6-20 type plyg/ receptacle and I undestand that the 20 vs 15 means the total max amps.

The question I have: Is there a reason to have a mix of L6-20 and 6-15 or just changing all my cords so that it will just work with the L6-20.

Are there any considerations I need to keep in mind, or can the tools use the higher max maps even when the machine will never hit the max.

I hope I make sence... Don't know much about electricity however I want to bring in someone that can install 220V on my garage but I want to make sure I ask the right questions so I get the right services...

Regards,
Luis

[Brian Gumpper]

The 6-15 is 15A as you stated and a standard straight plug. The L6-20 which is what I use is a locking connector. Either one will work, it's just a matter of what you want to use.

[Kent Fitzgerald]

Hi, Luis

As Brian mentioned, the L is for locking. I personally see no need for locking receptacles in a non-industrial shop. I'd suggest that you install 240V, 20A circuits with regular 6-20 receptacles, which will accept either 15 or 20A plugs.

[Bruce Shiverdecker]

There are two reasons for having dedicated outlets (receptacles)

1. To make sure you don't plug a tool that draws more current (Drawing 20 amps on a 15 amp circuit) than the wiring will SAFELY handle.

2. To keep persons who have little or no knowledge of what you have available from plugging incorrect machinery into an outlet. Such as a 3 phase motor into a single phase outlet. This case would cause the motor to overheat, fail, and possibly cause a fire.

Locking plugs/ receptacles are used where you want a little more protection from the plug being accidentally knocked out.

An example of what could happen is: For some reason, a guest in your shop trips on a cord of a saw you are using. The first thing you do is look for the reason the saw stopped. You have left the saw, with the work still in it. Your guest plugs the saw back in, it starts up, and you are looking at a potential disaster.

Locking plugs help hold the plug in the receptacle in this instance, thereby cutting down the chances for an accident.


Something else to consider, if you do not have automatic shutoff of a machine in the case of a power interruption, is to install a motor starter, so that the motor will not just start up when power is restored.

One other thing. Plugging a tool rated at 15 amps in a 20 amp outlet is fine. That is why a 20 amp 120 volt single phase receptacle has the "T" slot. It accepts either 15 or 20 amp.

Hope this helps a little,

Bruce

[Kent Fitzgerald]

An example of what could happen is: For some reason, a guest in your shop trips on a cord of a saw you are using. The first thing you do is look for the reason the saw stopped. You have left the saw, with the work still in it. Your guest plugs the saw back in, it starts up, and you are looking at a potential disaster.

Locking plugs help hold the plug in the receptacle in this instance, thereby cutting down the chances for an accident.

Something else to consider, if you do not have automatic shutoff of a machine in the case of a power interruption, is to install a motor starter, so that the motor will not just start up when power is restored.

Bruce, I understand your point about the hazards of accidental disconnection. BUT, if people are tripping over wires, better cable management is the solution, not locking plugs. Cords should not be lying across the floor, and the tool recepatacle should be within sight and reach of the operating position, so the scenario you describe could never happen. I do agree that automatic restart protection, such as a magnetic starter, is a wise precaution.



One other thing. Plugging a tool rated at 15 amps in a 20 amp outlet is fine. That is why a 20 amp 120 volt single phase receptacle has the "T" slot. It accepts either 15 or 20 amp.

Yup. The same is true of 240V receptacles, as I posted above.

Cheers,
Kent

[Luis Oliveira]

Hi all, Thanks for the replys so far. Very informative!!!

Some of you suggest 240v 20A as opposed to 220v 20A.
Would the tools be able to run on a 240v 20A when the manual say 220v 20A single phase.

Luis

[Kent Fitzgerald]

Hi all, Thanks for the replys so far. Very informative!!!

Some of you suggest 240v 20A as opposed to 220v 20A.
Would the tools be able to run on a 240v 20A when the manual say 220v 20A single phase.

Luis

In practice, the terms 240V, 230V, and 220V are used interchangeably.

[CPeter James]

I think that 220V is outdated term. Most places use 120/240 for single phase or 120/208 if the service is 3 phase. Check you voltage with a decent meter and I'll bet it is closer to 240 than 220.

On the plugs and outlets, I switched all my 240V circuits to 20A using the L6-20 type. I have a 10ga extension cord with L6-20 plug and socket. It allows me some flexibility as all my tools are on wheels.

CPeter

CPeter

[Bruce Shiverdecker]

Kent, I believe that on 240 volt plugs and receptacles (even in straight blade configurations) there is only one voltage/amperage allowed for each configuration. That is, unless there have been National Electric Code changes that allow it since I retires three years ago.

Also, 120, 115, 110 volt, 220,230,and 240 volt are "nominal voltages" as they fluxuate across the energy grid.

Bruce

[Kent Fitzgerald]

Kent, I believe that on 240 volt plugs and receptacles (even in straight blade configurations) there is only one voltage/amperage allowed for each configuration.
True for 30A and above, but NEC (2002) 406.7 states in part: "a 20-ampere T-slot receptacle or cord connector shall be permitted to accept a 15-ampere attachment plug of the same voltage rating."

As a matter of practice, the commonly used NEMA 6-20R (240V, 20A) receptacles are specifically designed to accept either 6-20P or 6-15P plugs.

Kent

[Jeff Horton]

To keep persons who have little or no knowledge of what you have available from plugging incorrect machinery into an outlet. Such as a 3 phase motor into a single phase outlet.


Someone like my FIL who brought over his RAS for me to tune up and try to repair. I was about to plug it up when he told me it was wired for 220V. BUT! It still had the standard 110V plug on it. :eek: And I would bet he had a 220V extension cord with a standard 110V 15 amp outlet in his barn to!

[Dan Oelke]

Someone like my FIL who brought over his RAS for me to tune up and try to repair. I was about to plug it up when he told me it was wired for 220V. BUT! It still had the standard 110V plug on it. :eek: And I would bet he had a 220V extension cord with a standard 110V 15 amp outlet in his barn to!

Hey! That sounds like my FIL. I am sometimes amazed he hasn't fryed himself when I see his contraptions of various 220 to 110 cords and "adapters" complete with wirenuts in the middle of the "cord" and lots and lots of black tape. (I won't even call the cheap crud he uses "electrical" tape)

[Luis Oliveira]

Thanks for all the replys, I really appreciate it.

Luis

[Bartee Lamar]

be careful when you are purchasing. The L6 and L5 plugs look the same but are NOT.... DAMHIKT.

I have standardized on ALL L6 for all my 220V stuff so I can move equipment around.

[Brian Gumpper]

be careful when you are purchasing. The L6 and L5 plugs look the same but are NOT.... DAMHIKT.

I have standardized on ALL L6 for all my 220V stuff so I can move equipment around.

Good point Bartee. I probably spent 20 minutes trying to find the L6 plugs being stuff was mixed up and ended up they were out of them.

I use the locking because I currently only have on 220V outlet and it is near my braker panel which is accross the garage and I use an extension cord.