Miller Cutmate 375, 120 or 240 Volts

[johns6]

It seems kind of odd since the machine is SUPPOSEDLY rated at 5/16, quality,at 3/8 and sever at 1/2. using drag cutting.
Using standoff it's rated at 3/8, Quality at 1/2 and sever at 5/8.
I think the machine is over rated. Before the one i bought broke down (2 days after i bought it). It was having a **** of a time on 3/16 and 1/4. like you already stated. All the cuts looked like they were severd.
Not bashing Miller but i would never get another 375. Thats why i bought a TD 51 **** near for the same cost. $1500.00 out the door. I do like the design of the cases on the Millers though.

Mig,

Thanks for your input, but my Miller dealer who is also a personal acquaintance is the reason for me getting the 375. The service I get is excellent and he is a Miller repair facility. If I am making a mistake it's not the first one. Actually, he likes the Esab 180. Sometimes I think we are splitting hairs around here. But thanks again.

[Scott V]

It seems kind of odd since the machine is SUPPOSEDLY rated at 5/16, quality,at 3/8 and sever at 1/2. using drag cutting.
Using standoff it's rated at 3/8, Quality at 1/2 and sever at 5/8.
I think the machine is over rated. Before the one i bought broke down (2 days after i bought it). It was having a **** of a time on 3/16 and 1/4. like you already stated. All the cuts looked like they were severd.
Not bashing Miller but i would never get another 375. Thats why i bought a TD 51 **** near for the same cost. $1500.00 out the door. I do like the design of the cases on the Millers though.

Mig,
I will say the 375 I worked worked really well. The most impressive Miller plasma I ran was the 125 c. For 12 amps it really did a good job. I could take or leave the 3050 model. It would do the job, but nothing special like the little one.

[HAWK]

johns6,

If your wiring supports the 30amp draw, then leave the breaker at 30amps and change out your plug to support 30amps. On the other hand if your machine will not draw more than 20 amps ( plug rating ), then you will be okay as is.

The safe thing to do is match the plug rating to the breaker rating and wire rating. Therefore, if you do not want to change out the plug, then yes change the breaker to a 20 amp.

[rb455ho]

Larger wire has more surface area. Current flows on the surface of the conductor. This is known as the skin effect. In addition, a larger wire has a lower resistance. This results in lower I^2*R power losses otherwise known as joule heat or simply heat losses. It never hurts to put a larger wire on things. However, this drives up production costs which opens up a whole other can of worms. The key to wire and breaker size is they must match. As the breaker is there to protect the wire from getting too hot and burning your facility down.

[HAWK]

ROB,

Thanks for putting OHM's law and a few other factors into plain english. I tend to be long winded at times-too many times.

[Scuppers]

That makes sense. I guess I just didn't look careful enough. Anyway, I have a6-20p I am going to install. Should I drop down from a 30 amp breaker to something smaller for the 375?

As to what comes on the machine, I looked at a new in the box Hobart Airforce 400 which is the same as a Spectrum 375 and it did have a 5-20P.

Thanks Again.

You're welcome.

Regarding the circuit breaker, if I understand you correctly, you mean matching the capacity rating of the breaker more closely with the current requirements of the Spectrum 375. (For example, change the 30 A breaker to a 15 A breaker.)

On the plus side, matching the breaker's capacity with the current requirements of the machine would provide an additional degree of safety. In the minus column, a closely matched breaker might trip during transients (e.g., the machine drawing more than 14 A if the supply voltage drops below 230 V). The decision involves a lot of factors, many of them dependent on a particular installation (e.g., size of wiring, fluctuations in the supply, etc.). You may want to consult an electrician to be sure.

Another thing I would consider, if you don't have it already: Installing a ground-fault circuit interrupter (GFCI). (See http://www.osha.gov/pls/oshaweb/owad...ONS&p_id=24468 for the Department of Labor's take.) 230 V GFCIs can be harder to find than the 115 V units, but they do add a degree of safety in case of a malfunction.

Good luck.

[johns6]

You're welcome.

Regarding the circuit breaker, if I understand you correctly, you mean matching the capacity rating of the breaker more closely with the current requirements of the Spectrum 375. (For example, change the 30 A breaker to a 15 A breaker.)

On the plus side, matching the breaker's capacity with the current requirements of the machine would provide an additional degree of safety. In the minus column, a closely matched breaker might trip during transients (e.g., the machine drawing more than 14 A if the supply voltage drops below 230 V). The decision involves a lot of factors, many of them dependent on a particular installation (e.g., size of wiring, fluctuations in the supply, etc.). You may want to consult an electrician to be sure.

Another thing I would consider, if you don't have it already: Installing a ground-fault circuit interrupter (GFCI). (See http://www.osha.gov/pls/oshaweb/owad...ONS&p_id=24468 for the Department of Labor's take.) 230 V GFCIs can be harder to find than the 115 V units, but they do add a degree of safety in case of a malfunction.

Good luck.

Scuppers and everyone,Thanks Again,

I looked again at the Online owners manual and it said on 240 volts to have a 20 amp breaker minimum. Since I used to run an air compressor on this outlet that has a 30 amp breaker that was installed by an electrician, I'm just going to change out my plug to a 6 - 20 P. Thanks again.

By the way Scupper I also have the Ridgid chop saw. Got it last year when Home Deport was having a big sale. It's been good.

[rb455ho]

A good rule of thumb is to never exceed 80% of a wires rating if using continuously. Example, #8 Cu should be circuit breakered @ 50 amps. 50*.8=40 amps max contiuous duty. Most devices are not ran %100 of the time so this is usually not an issue. Again the breaker is there for the wire. As long as your circuit can handle the machines load, and the breaker matches the wires max ampacity, you will be fine. The machine does not know whether you have 26 gauge or 0000 it only sees the voltage. Barring a short circuit it will only draw a finite amount as a function of the voltage and its internal impedance (resistance if only a resistive load, no Xc or Xl).

[Sberry]

Hank hit a couple of things to keep it simple but you will be allwed to use the 30A but not with a 20A recept. The recept cannot be lighter than the breaker size. There is an exception for small welding machines provided the circuit conductors are not oversize, in other words 20A recept, 12 wire, allowed to use a 30A breaker. I can look up the code sections but I am tired now, I can see how this can be confusing. Wires can be de-rated from Art 310 for welding machines according to Art 630.11. Here is some things to look at for those interested. 210.21 (B) (1) I think what it implies is for these small machines you can actually de-rate the recept provided it isnt lighter than the conductor ampacity. Its in the book in another spot but cant recall where. Hope this clears some up,,,,, hahahahahahahahaha

[Sberry]

So, if you are going to use the old comp circuit and it has 10 wire and you are going to use a 20A recept you must change the breaker to a 20. If you were to use the 30A breaker you would have to change the wire to a 12. Correct????

[Scott V]

Mig,

Thanks for your input, but my Miller dealer who is also a personal acquaintance is the reason for me getting the 375. The service I get is excellent and he is a Miller repair facility. If I am making a mistake it's not the first one. Actually, he likes the Esab 180. Sometimes I think we are splitting hairs around here. But thanks again.

Esab 180? Do you mean Handy plasma 380? If he meant that one, run away fast. They blow up and hurt the ears. That is a import, Sweden. The 550 was a import for a while and not very good either. Esab started making the 550 in the states and it has improved a whole lot.
Did I mention the Esab 380 blows up real good!!!!!

[johns6]

I feel like I opened up a can of worms with my question. It has been very infromative. All I can say now is without looking , I don't know what wire size I have. But it was installed by an electrician when I bought the house 12 years ago.The run from my panel is 4 feet.I showed him my air compressor with the 6-20 P plug and I never until the other day bothered to look at the breaker size. This all started when I got my Miller 375 plasma. At the time it seemed the simplest thing to do was just to change out the plug on the 375 which I did. All I can say now is that everything work fine as it has for the past 12 years. But I do now understand a whole lot more about matching up breakers to proper receptecles.

[johns6]

Esab 180? Do you mean Handy plasma 380? If he meant that one, run away fast. They blow up and hurt the ears. That is a import, Sweden. The 550 was a import for a while and not very good either. Esab started making the 550 in the states and it has improved a whole lot.
Did I mention the Esab 380 blows up real good!!!!!

Yes Scott I did mean the Handly Plasma 180. That is interesting, would like to know more about it.

[Scott V]

Handly Plasma 180?

I have never seen that one? Esab has been tying to match the cutmaster 38 but so far no luck. The 380 was 230 volt only, but was cheaper in price. (stupid but small)

[Sberry]

John, how big of a comp was it, or is it? The general rule is 20A plug, 20A breaker. It could be as small as 14 wire and still be legal although it is likely 12. That is if it is 240V, I been back re-reading this thread a little, was your circuit 120 to start with????? A 6 series recept is for 240V.