Input Amperage Question

I'm about to buy either a Miller Maxstar 150 stl or Diversion 165. I've done a lot of research and am familiar with the capabilities of both.

My question is the recommendation for the circuit needed for the 165. Looking at specs on miller's website, the 165 draws 25.5 A at 165 A output for 15% duty cycle. I read some posts here saying the machine will run fine on a 30 amp circuit.
http://www.practicalmachinist.com/v...l-welder-question-newbie-needs-advise-202823/

The guy at LWS (Praxair) says that it nneeds a 50 amp circuit. Is 30 amps pushing it?

They quoted me same price for 165 and 150 (w/ TIG package including remote).

My TA-185 draws about 29amps at full power, it has a 10/3 wire coming out of it. For mine I put a regular 50amp plug which is wired with #8 and a 40amp breaker at the panel. It has never tripped in a few years of using it a lot, often at full power for longer than the duty cycle of the machine. I think 30amp may work fine for your machine, if it trips just put a 40amp. If it trips that something is wrong. Its only a few dollars difference for the breaker anyway, mostly make sure your wiring is up for it if you're running a long distance from the panel.

Miller has those spec's. on their site.

more input on input

I would only add that if you are concerned about the maximum rated input current and the welder is running 15% duty cycle at max, you should be looking for a larger welder.
I used a Maxstar 140 for years on my job truck, and most of the time I used 3/32" 6010 around 55-65 amps. While that is well below the maximum capability of the welder, it still kicked out on over heat once in a while, even when the welder is supplying less than 50% of stated maximum output current.. Now fire that box up when the ambient temperature is 90F... it sure doesn't get better...
If you are using the welder in a sane area of the output parameters, you will be drawing much less than the 30 amps max.

For what I do, or plan to with either machine, I'm not overly concerned w/ the duty cycle. We've got larger rigs at work. I'm leaning towards the maxstar since it will handle stick and tig. This more along the lines of what I do. Can't stick w/ the diversion but can do alum.

Courtiron: I've seen more than a couple of posts by guys saying the maxstar doesn't handle 6010 well at all. 6011 no problem.

I've been there...

dave powelson said:

Miller has those spec's. on their site.

Click to expand...

Here:Miller - TIG Welders - Diversion 165

I see 1 phase 230 v input, 50 amp cord and plug, but maybe I'm missing something. It's the same place I got duty ratings with amperage draw.

can't find the spec's.?

recoilless said:

Here:Miller - TIG Welders - Diversion 165

I see 1 phase 230 v input, 50 amp cord and plug, but maybe I'm missing something. It's the same place I got duty ratings with amperage draw.

Click to expand...

there's a product literature pdf file on that page, open it and:

Rated Output
60 A at 12.4 V, 100% Duty Cycle
150 A at 16 V, 20% Duty Cycle
165 A at 16.6 V, 15% Duty Cycle
Model
Diversion
165
Input
Power
230
VAC
Max. Open-
Circuit
Voltage
80
Welding
Amperage
Range
10 –165 A
Amps Input
at Rated
Output
8 A (.20)*
23 A (.20)*
25.5 A (.20)*
KVA
1.8 (.04)*
5.3 (.04)*
5.9 (.04)*
KW
1.2 (.02)*
3.7 (.02)*
4.2 (.02)*

***suggest you demo one of these-first. You might be disappointed.
It's a questionable excuse for a tig welded, IMHO.

Dave:

Before I read your post, I searched again and found this.

http://www.millerwelds.com/om/o232895g_mil.pdf
About halfway down it states:

Rated input at 150 amps, 16v, 20% duty cycle: 21amps AC 23 amps DC
Max rated circuit breaker, time delay : 25 amps AC 30 amps DC
" " " " , normal duty : 30 amps AC 35 amps DC
Minimum size conductor : 14 (?)

I'm actually leaning more towards Maxstar 150, just was getting somewhat conflicting advice from others about input rqmt's.

Maxstar

While I haven't seen the posts, I can see where one may have problems with the Maxstar's that are oriented towards tig. The 140 I used had no arc force control, while the 200 that I have now does.
The arc force control allows the inverter machines to emulate old school motor/generator and transformer machines... which is important to old farts like me as that's what I grew up with.
The old Lincoln and Hobart motor/generator welders were a joy to stick weld with. 6010, I would say, is the more difficult rod to start compared with 'drag' rods.
The 140, because it has no arc force control, is a pain to start any rod with, but its small size, 110/220 capability and the fact that that was what I had were a balancing factor.
The Maxstar 200 and my XMT304 are not only great machines for stick but serve me quite well for DCEN tig. No aluminum capability here as yet. While the 150 has 'Adaptive Hot Start' for stick, I have not had the opportunity to use one. I will try one as soon as I am able to, but that should make stick welding much easier.
If you have the opportunity to try the 150 and the 200 side by side I would recommend it, but I doubt that you would be disappointed with either.

ps. While repairing my XMT304 I was told by one of Millers factory service techs to always start the machine in the CV mode. As soon as the display settles down and the machine is on line, change to the CC mode.
I don't know the specifics,not to sure electronically why that helps but after replacing a number of big buck parts inside I figured why not... what can it hurt. It's cheaper than a rebuild...

pcs

I've heard good things about the 304and even had a chance to pick up a used one from a friend of a friend. However, it became quite clear to me that tis particular machine had been "lost" at one of the local steel mills and "found" by this individual. Not goin" there. Shame, I tried it out and liked it. Several members here have good experiences with them, Ries comes to mind.
I'm getting the 150, deciding between the STL & STH .

Wire size and the load

Regardless of the machine, the wire size and design are the same.

The duty cycle has nothing to do with the wire size (as long as the load is within the ratings of the wire), rather the duty cycle is related to the power supply in the welder.

The circuit breaker has limits to duty cycle as home units will trip at a lower percentage of rated current sooner than the commercial units which usually will require closer to rating for longer period of time to trip.

So if the circuit (breaker, wire and connections) is designed properly then none of the "duty factors" are related.

If your machine draws 29 amps then wire size minimum is 10 and breaker size 30, but given 29 amps is just under 30 the breaker may trip if the duty cycle is too great.

Also consider line losses, a 10 guage wire carries 10 amps, but it also has resistance which allow voltage drop, longer runs will cause higher drops at higher distances, and this is where it gets interesting.

Depending on the power supply of the welder, it will do its best to provide the stated output, we dial in " amps" but the output is in power which is in watts, so if there is a voltage drop in the wire between the breaker and the welder the power supply will draw more current to output the same power (power = amps * volts), to maintian same power with a lower voltage amps must rise.

Price difference at the breaker is pennies, price difference for the wire is fair, but labor difference is minimum depending on limitations of the install.

If one takes minimum requirements then doubles that one would avoid being too close to the edge of the design, install 60 amp breaker and use #6 wire instead of #10.

One example from a calculator, your mileage may be different as requirements vary from place to place as well as equipment (acceptable voltage drops etc).
The voltage drop for 30 amp load with a 30 foot loop (15 foot breaker to outlet) with #10 or using #6 wire allows for a 80 ft loop (40 ft breaker to outlet)

#6 is not that much more expensive but the difference in performance is worth the investment.

All smaller miller machines come with the standard 50A 240v plug. Thats why the welding supplier thinks it needs a 50 amp circuit.

Use the breaker size that is specified by miller. You do not want to oversize the breaker, especially on an inverter. If something goes wrong there is no protection for the machine and there can be significantly more damage if something blows if you have a 60 amp breaker over the 30. There is no internal fusing.

The 150 is a great little machine. I had one for a couple years and they run nice. I would spring for the STH, it also has some pulsing built in. Never used Diversion.