electrical requirements for Miller 211

[HCJtractor]

The more I read, the more confused I am about what I need for my Miller 211 Welder, which is a dual 120 or 230 V, supplied with two plugs. In the 230 V mode, it appears the Amperes Input at Rated Load Output is 24.3. Ideally, I know a dedicated 50 amp breaker is ideal. However, my shop already has a 30 amp circuit, although with a different style plug. My question is can I make a short extension cord to be used as an "adapter" with a 20 amp male plug on one end and a Nema 6-50 female on the other, using appropriate heavy cord? This way I could leave the shop wiring as is.

I am wondering if there is an alternative to running an entire new 50 amp circuit to be able to use this welder in the 230 V mode.

 

[kennyd]

I am wondering if there is an alternative to running an entire new 50 amp circuit to be able to use this welder in the 230 V mode.

In my mind, this answer is NO. DIRTFT (do it right the fist time)

 

[_RaT_]

I am somewhat confused on your question. All you need is a circuit rated for 30 amps and even at that, the duty cycle will actually never allow this circuit to get hot. Why a 50 amp breaker being ideal, you won't trip a 30 amp @240V if your max current is correct for the Miller 211.

If you needed a cord that was adaptable, there are 30 amp 120V plugs. I also thought that Miller had this adapter as part of the welder when it was purchased.

The more I read, the more confused I am about what I need for my Miller 211 Welder, which is a dual 120 or 230 V, supplied with two plugs. In the 230 V mode, it appears the Amperes Input at Rated Load Output is 24.3. Ideally, I know a dedicated 50 amp breaker is ideal. However, my shop already has a 30 amp circuit, although with a different style plug. My question is can I make a short extension cord to be used as an "adapter" with a 20 amp male plug on one end and a Nema 6-50 female on the other, using appropriate heavy cord? This way I could leave the shop wiring as is.

I am wondering if there is an alternative to running an entire new 50 amp circuit to be able to use this welder in the 230 V mode.

 

[crazyal]

The more I read, the more confused I am about what I need for my Miller 211 Welder, which is a dual 120 or 230 V, supplied with two plugs. In the 230 V mode, it appears the Amperes Input at Rated Load Output is 24.3. Ideally, I know a dedicated 50 amp breaker is ideal. However, my shop already has a 30 amp circuit, although with a different style plug. My question is can I make a short extension cord to be used as an "adapter" with a 20 amp male plug on one end and a Nema 6-50 female on the other, using appropriate heavy cord? This way I could leave the shop wiring as is.

I am wondering if there is an alternative to running an entire new 50 amp circuit to be able to use this welder in the 230 V mode.

I ran my Lincoln 255 MIG off a 30 amp circuit for 10 years without a problem. I couldn't upgrade the wiring so I was stuck. Never once tripped a breaker. The welder came with a Nema 6-50 connector (rated for 50 amps) so when I built my garage I ran 100 amp service to it and I finally got it on a 50 amp circuit.

If I'm reading your post right Miller requires a 40 amp circuit but it has a plug on it for a 50 amp circuit. It requires 24.6 amps at max power at 230v. Since breakers are designed to trip at about 20% less than what they are rated for a 30 amp breaker may trip at 24 amps. However the chances of you tripping it are slim to none. I would verify that the existing wire is the correct gauge for the breaker (since there is a chance that you will be operating near the maximum rating). If so then you will be fine if you do as you suggest, make a cord out of thicker wire as an adapter/ extension.

However if you forget and buy something that will use more than the 30 amps your breaker is rated for you will trip it. You'll also risk the chance that if the breaker is defective you could start a fire. Of course it's the same risk you face if you plug something like an AC that requires a 20 amp circuit into a circuit with a 15 amp breaker.

 

[Willl]

Ditto on Kenny.

Do you have room in your box for another dual breaker ?

 

[HCJtractor]

I agree to the "do it right" theme, however I am not sure of what is right is for this welder. I need to call Miller for clarification. It never states what size breaker to use in 230 V mode. In 120V, it list "Amperes Input at rated load output" at 20, but the supplied plug is a 15A style and it clearly shows it plugged into a NEMA Type 5-15P plug. Isn't this a 15 Amp circuit? The Nema Type 5-20P plug isn't even included, as this is an optional item. So I assume I can operate this on a 15 A circuit, in the 120V mode.

In 230V mode, the plug Miller supplies has "20A" stamped on it, but is the Nema Type 6-50P style. In the "Electrical Service Guide" for 230V input, it list "Max Recommended Standard fuse Rating as 25 for Time delay fuses and 35 for normal operating fuses. It list minimal input conductor size as 14 AWG. For "a "circuit breaker" it says to use "a breaker with time-current curves comparable to the recommended fuse." No other mention is made for recommended breaker size.

So this is what is confusing to me. The only thing that indicates the need for a 50 A circuit is the plug style. The 6-50P outlet I bought at Home Depot says 50 A. The plug supplied with my welder is stamped with 20A.

This welder is the low end for a 230V in power. It tells me I can use a 14AWG extension cord. So it seems that a 50 A circuit is overkill.

So back to my original question. Can this be operated safely on a 30A circuit, and if so how do I plug it in. I realize changing the outlet to a 6-50R on a 30 A circuit is not proper (but would probably work fine if this is the only tool ever used), so thats why I wondered about an "adapter"

 

[HCJtractor]

If you needed a cord that was adaptable, there are 30 amp 120V plugs. I also thought that Miller had this adapter as part of the welder when it was purchased.[/QUOTE]

Two plugs came supplied, a Type 5-15P for 120V and a 6-50P for 230V

 

[HCJtractor]

I ran my Lincoln 255 MIG off a 30 amp circuit for 10 years without a problem. I couldn't upgrade the wiring so I was stuck. Never once tripped a breaker. The welder came with a Nema 6-50 connector (rated for 50 amps) so when I built my garage I ran 100 amp service to it and I finally got it on a 50 amp circuit.

If I'm reading your post right Miller requires a 40 amp circuit but it has a plug on it for a 50 amp circuit. It requires 24.6 amps at max power at 230v. Since breakers are designed to trip at about 20% less than what they are rated for a 30 amp breaker may trip at 24 amps. However the chances of you tripping it are slim to none. I would verify that the existing wire is the correct gauge for the breaker (since there is a chance that you will be operating near the maximum rating). If so then you will be fine if you do as you suggest, make a cord out of thicker wire as an adapter/ extension.

However if you forget and buy something that will use more than the 30 amps your breaker is rated for you will trip it. You'll also risk the chance that if the breaker is defective you could start a fire. Of course it's the same risk you face if you plug something like an AC that requires a 20 amp circuit into a circuit with a 15 amp breaker.

How did you plug in your Miller 255 MIG into a 30 amp circuit? That is my confusion.

 

[HCJtractor]

Ditto on Kenny.

Do you have room in your box for another dual breaker ?

Herein lies the problem. I am using this welder in a friend's garage. He has a230 V outlet there for occasional use. I need to verify the breaker size, but I assume it is a 30A. The existing outlet obviously doesn't mate with my Miller welders plug. Since I am borrowing his space, I am not at liberty to rewire his garage ideally. I can always use it at the 120V mode there, but would rather have the increased power of 230V if it can be done safely.

Could I run this welder off a 8000 W generator? My generator has a 230V outlet, 30A locking plug style. Same question, if so, how do I plug it in?

 

[Sumpter]

To do this the legal way and the right way you need to size your breaker at 125% the load you have and 220 is always better than 120. It is also cheaper in the long run. Less amps are used which mean less power used.

If you have 24.3 amps X 125% that comes to 30.375. The next larger size breaker should be used and that is 40 amps. A 50 is to large and will not protect the circuit properly. You will still use a 50 amp plug since a 40 amp is not made. Your wire size should also be no smaller than a #8.