“standard” 30A 240V connector

[Max]

I have a new to me 3 HP cabinet saw that I need to connect up. It came with a 20A 240V plug, but I think that 3 HP requires a 30A circuit, correct? FLA is only 14A, but I think the NEC is by HP. Longer term I will likely use a welder in that socket as well, so out the the variety of options I wanted to know what the best plug/sicket type was.

Thank you,

Max

As background, I recently added a subpanel and new wiring to my garage. So I already have wires to a box via EMT - 10 AWG THHN....

 

[pattenp]

If it's factory wired with a 20A cord and plug then that is what it needs.

 

[wyliesdiesels]

What he said ^^^

Also, depending on the welder model, you may need a 6-50.

 

[Max]

It’s a 20 yo Unisaw, and I have no idea who might have done what with the cord previously . But it’s no problem to use a 20 A so that’s what I’ll do. Thank you for the help.

Max

 

[pattenp]

Do a web search for the instructions for your delta saw and you may find the suggested circuit size.

 

[theoldwizard1]

Also, depending on the welder model, you may need a 6-50.

This is kind of my "personal pet peeve" ! Almost all welder come with that plug regardless of whether they need it or not. In many (most ?) shops, the outlet is wired to a circuit with much less than 50A capability, commonly 30A or even 20A.

It just does not seem right !

 

[Max]

Good point pattenp - I did find a pdf of the manual and it has the 20A connector. So that should be ok. Short term I am going going to use that connector and I’ll switch to a 20A breaker in the panel.

Longer term (once I start welding) I’ll match the welder connector at the outlet and go back to a 30A breaker. It’ll be easy to build an adapter box with both a 30A cord plus the 20A receptacle and a 20A breaker in it...

Max

 

[sberry]

This is kind of my "personal pet peeve" ! Almost all welder come with that plug regardless of whether they need it or not. In many (most ?) shops, the outlet is wired to a circuit with much less than 50A capability, commonly 30A or even 20A.

It just does not seem right !

Its really well thought out. The code people and the engineers that did this KNOW what they are doing. I have typed it in various posts over the years. It is to ENABLE them to run from common welder circuits.
They allow them to use smaller wire and smaller breakers in the same outlet. You do not have to wire it for the full 50A,,,, but,,, it comes 50 end allowing it to be connected to up to 50.

 

[alfredeneuman]

I don't know why receptacles (not hardwiring) for welders & motors are permitted to have "less than" wiring ie: #10 or 12 on a 50A brkr & recp

Someone might see the 2 of them at a later time and plug a 45A load (such as a kiln for firing ceramics) into the recp.

 

[MoonRise]

I don't know why receptacles (not hardwiring) for welders & motors are permitted to have "less than" wiring ie: #10 or 12 on a 50A brkr & recp

Someone might see the 2 of them at a later time and plug a 45A load (such as a kiln for firing ceramics) into the recp.

Don't feel like digging back through old NEC books, but IIRC there used to be a note that 'undersized' wiring (for the breaker and receptacle 'size') used for duty-cycle limited loads (like a welder) were 'supposed' to be labeled/marked as such and were supposed to be also marked as 'dedicated' to that particular usage.

Just to avoid the scenario you mentioned.

 

[alfredeneuman]

...there used to be a note that 'undersized' wiring (for the breaker and receptacle 'size') used for duty-cycle limited loads (like a welder) were 'supposed' to be labeled/marked as such and were supposed to be also marked as 'dedicated' to that particular usage.

If there was, they probably abandoned it because people didn't pay any attention to the label.

 

[sberry]

Because that stuff doesnt cime with a welder plug. Its hard wired or comes with range plug. If its welder wired for 30 turning a machine like a buzzer up far enough to catch the wire on fire will trip the breaker before it damages the wire.
The code people didnt hatch yesterday, there are decades of usage and forensics. If this was a problem they would have fixed it in the last 75 years.

 

[sberry]

I asked this at a conference with fire investigators. No one had ever atributed a fire to a welder or dedicated comp circuit. All kinds of other **** with the use of them, grinders too.
Look at the reality here,, just mention the fact you can use 12 here on forum and people get anxiety attacks. Most of these circuits are wired up a size minimum and in some cases 3 sized above the allowable standard. Look in the real world, more wired with 6 than 12.

 

[sberry]

Look how many machines that need 14 are connected to 6. Millions of machines,, most come 12 cord.

 

[alfredeneuman]

Because that stuff doesnt cime with a welder plug. Its hard wired or comes with range plug.

From the Big Ceramic Store:
"208 V and 240 V Kilns are designed for 30, 40, 50 amps or more. At 48 amps and above, kilns do not come with plugs; instead they must be wired directly into your power supply."

(They also show not a range plug, but the same 6-50 as welders use.)

 

[sberry]

If was curious if anyone had ever seen a factory 6-50 on other equipment. Are they factory or dealer installed?
I have never bought anything that had it, cant recall ever seeing it. Must be so though.

 

[sberry]

Is the Big Ceramic Store a chain, a dealer, never heard of it. I was curious about kilns though.

 

[alfredeneuman]

Re: “standard” 30A 240V connector

I was curious about kilns though.

Then why did you post this "Because that stuff doesnt cime with a welder plug. Its hard wired or comes with range plug." if you weren't sure?

All plug in equipment that requires 30A or more of only 240 or 208 volts
is most likely to come with that configuration (there is no 40A). There is no need for a neutral.
In the case of kilns, it is 25A because you have to figure kilns at 125%.

 

[sberry]

So,,, Is the end dealer or factory? I have ne er seen or bought anything that come with that plug besides welder.
Now you day most likely,, so you are not sure either?

 

[alfredeneuman]

Do your own research...instead of talking through your hat.
I said "most likely" because I'm sure someone would give an example where it's not true.

 

[sberry]

I was curious if you actually knew, guess not.

 

[GarageGuy89]

If there is one thing I love about electricians, it's the debate over who knows the correct code!

Love these threads.

 

[sberry]

I guess I over estimate some people. I was hoping to get some elaboration from someone I thought probably knew more about it than I did and it was just general conversation but I must need to put little disclaimers in at every point and dumb it down a little.
( I dont recall seeing) Have never seen a direction requiring the label on a welder recept,,, it could have been removed but I doubt it.
I was trying to make a point about recepts, that the code people allow this wiring and recept and that if there was a reason it must be wired some other way that they likely would have thought about it and changed it given the decades its been this way.
I installed a larger pressure washer that was 240 but its been sooooo long ago and I think my helper wired it up, I do not recall the wire/end it came with.

 

[alfredeneuman]

You said this in your 2nd post "Because that stuff doesnt cime with a welder plug. Its hard wired or comes with range plug." unequivocally.
I may be wrong, but that doesn't sound much like "hoping to get some elaboration"