120V Flux Welder, 2000W Inverter. What?!!

[12VoltInstalls]

repeated each test three times and took the highest values:
B - 16Amp
C - 20Amp
D - 25Amp

That would be very consistent with a 2000W inverter objecting to the mig

I’m not asking for a favor or for you to go to any trouble. I’d be uncomfortable and feel assumptive doing that. But if it interests you and it doesn’t take a lot of effort I’d be curious about fluxcore versus mig welding.

I ran a few minutes yesterday with fluxcore (fixing the handle on a 10# slide hammer) and after a few minutes it shut off (AND tripped the 20A GFCI somehow. But it does that now and then to the inverter generator, too, so it’s something about stopping and starting that does something- have trouble actually believing it’s actually ’real’ current on the G but more like an imbalance when the current collapses; I ain’t no EE)

I’m not going to try to weld anymore until I’m 3000W inverted or have a 6048 or something. That 2000W inverter is a great cheap unit and there’s no sense in my wrecking the thing.

 

[OffGridForGood]

That would be very consistent with a 2000W inverter objecting to the mig

I’m not asking for a favor or for you to go to any trouble. I’d be uncomfortable and feel assumptive doing that. But if it interests you and it doesn’t take a lot of effort I’d be curious about fluxcore versus mig welding.

I ran a few minutes yesterday with fluxcore (fixing the handle on a 10# slide hammer) and after a few minutes it shut off (AND tripped the 20A GFCI somehow. But it does that now and then to the inverter generator, too, so it’s something about stopping and starting that does something- have trouble actually believing it’s actually ’real’ current on the G but more like an imbalance when the current collapses; I ain’t no EE)

I’m not going to try to weld anymore until I’m 3000W inverted or have a 6048 or something. That 2000W inverter is a great cheap unit and there’s no sense in my wrecking the thing.

I have a project coming in next week that will definitely use both the Gas and the Fluxcore - if we can swing it, we will run the same (Mig-10) for both areas and through the new meter on the supply - to capture the max current in each senario. Yeah, I am very curious to know the results as much as you are!
The shop runs on my main off grid solar - ie the 3 MPP 6048's and 53kWh ESS system. The small MPP2724 is my mobile unit mostly used when I need a grinder or something far away from the shop/house outlets, or camping/trips to the cabin. So the testing will all be on the main solar, not sure if that makes much difference, I can imagine the smaller set up may experience some voltage sag during those brief moments on start up, which may mean higher current flow. But now @Hedges has me wondering if voltage sag would actually lower the in-rush briefly.
(Torture for me, I just gotta know!)

 

[12VoltInstalls]

So the testing will all be on the main solar, not sure if that makes much difference

In general ‘recommended use’ terms, no, it makes no difference.

now @Hedges has me wondering if voltage sag would actually lower the in-rush briefly.

That plays out.
I can sorta run ‘C’ okay on a 75’ 16ga cord (shhh!) but not quite as well on a 12ga 50’ cord because starting the arc shuts down the inverter more readily. Hedges comments sorta explained that a bit, and I believe prior to that (above) I noted that I speculated the resistance might act as a buffer.
I couldn’t find my 1/4”-1/2” socket adapter today (setting pinion preload with a 1/4” drive inch-lbs torque wrench; socket is 1/2” drive 27mm/1-1/16”) so I cut a 1/4” extension I hate and welded it to a male 1/2” drive end and used the inverter instead of the generator. On the 16ga cord (shhh…)
It cut out twice on ‘C’ but the adapter will never see ‘big numbers’ so I finished on B. This was fluxcore.

 

[12VoltInstalls]

think he's better off getting a bigger inverter

think he's better off getting a bigger inverter

impressed with my 6048's they do it all and I don't baby them. They are $943USD each and they often have inventory in US warehouse. Idle consumption is pretty high - I average about 75W continuous, bit lower than this at night with few loads, bit higher when pushing them hard. The 6048 outputs 120/240

Been vacillating a bit on this.

I’m inclined to buy a 6048 from watts247 and do a totally independent system for the shop (except for a 12ga feed from house for two light switches, one outlet as I would leave the 6048 turned off except when needed; sortofa use it like a generator but without noise or gasoline.)

I believe the 6048 uses a low frequency inverter. That’s a benefit.

But ‘some’ say the 6048 is junk and won’t last. I’m not convinced that’s true.
Therefore I wonder: should I just close my eyes and do parallel LV6548’s?

I’d HAVE TO have two 6548’s for 240, but a single 6048 might do it. I could add a second 6048 later if necessary but using 6548’s is all the money up front.

My 240VAC stuff is only a Speedair 5HP compressor and the Primeweld TiG 225.
The 120VAC tools of consequence are the 15A Delta tablesaw, 2HP 120V compressor, two Lincoln 110 wire welders, and probably the bigger wood lathe. The makita compound saw and everything else is low enough amps to not be concerned, though there’s times I’ll want 12A dust collector and 2.25HP router running simultaneously which might crowd a single 6048.

Of course “ideally” I’d just buy a pair of 6548’s or one of the 8kW LF bigname units $$$ but if a single 6048 works….
There’s also the benny that two 6048’s is 12kWh if I have to go that way.

Am I overthinking or under-thinking?

 

[Hedges]

Sufficient inverter could deliver the 5x starting surge of motors.

240V from inverters could be stepped down to 120V through a transformer for 2x the current. Auto transformer rather than isolation handles 2x the power for same size. Feeding windings 50% of rated voltage makes it much more ideal, lower no-load current, but handles 1/2 the power.

Two tools simultaneously of course could be fed by two inverters. Of course start one at a time.

 

[12VoltInstalls]

240V from inverters could be stepped down to 120V through a transformer for 2x the current

So you wouldn’t do the 6048?

 

[Hedges]

I'm not sure which brands/models of inverter being discussed.
I think two stacked 120V inverters is better than two 120/240V inverters in parallel (in general, not referring to bit motor loads). Some share current well, some not as well. Pass-through from grid only gets balanced by resistance.

What I meant was, if the inverters don't internally have a transformer capable of delivering 100% of wattage to a 120V load (maybe because they contain two 120V HV inverters), then an external transformer could be used to do that. Just a brute-force approach if your tools draw too much for inverter's 120V output.

Brush type motors can soft-start on lower voltage, or with a speed control (probably a nasty waveform for inverters.) Induction motors want it all, right now. Better phase shift of starting winding (hard start) and Easy-start or single-phase VFD could help. Would rather have 3-phase, then reduced voltage works even for induction motors.

 

[OffGridForGood]

I’m inclined to buy a 6048 from watts247 and do a totally independent system for the shop (except for a 12ga feed from house for two light switches, one outlet as I would leave the 6048 turned off except when needed; sortofa use it like a generator but without noise or gasoline.)

Interesting idea, never tried this. Would cut down on the idle consumption.

I believe the 6048 uses a low frequency inverter. That’s a benefit.

Not the MPP LV6048 - I have three of these, they are HF. The low frequency version is the LVX 6048 - even higher standby consumption, but you will avoid mostly buy shutting off when not in use.

But ‘some’ say the 6048 is junk and won’t last. I’m not convinced that’s true.

I have three, from 2021, 2022, 2023 all work together right out of the boxes, I run them hard at times (although try not to!) I can't see any problem with them - they do what they say they will do. String PV voltage max 150vDC is the weak aspect against other inverters up to 600vDC. I don't mind for the PV panels that are 20-30 feet away, not a big deal for me.

Therefore I wonder: should I just close my eyes and do parallel LV6548’s?

The older ones that are 250vDC PV strings are better than the newer ones - See @LithiumSolar 's video comparing them.
I think Watts247 has these at reduced price still - check his website. You need two 6548's to get 120-240volt. I don't have this model, but from the guys on here like @EastTexCowboy they are good solid units. To expand you can't do three, you need 2 or 4 units IIRC.

For your shop set up: do you need 240volt? You can set up the MPP 6048's for 120 only (and get full 6500W output) OR you can set up just one MPP 6048 and have 120-240 with just one inverter, 3250W per 120v Leg, or 6500 on 240.
Expansion is easy since they just parallel up 1 to 2 to 3 (three is max).
Before someone chimes in "The 6048 is only 6000W" they are incorrect. On the unit it has max continous output of 27.3A x 240v = 6552W, in split phase you get half of this per leg. I can tell you I normally shoot for 75-80% of max output to treat the inverters gentle, but there are times when they need to output full capacity and they handle it.
You need 200A capacity battery behind the MPP6048 for it to perform to it's rated max. With three inverters I needed 600A behind them. This is called out in the manual, and they need it.

If I was you today, knowing everything I learned over the last three years, I would also consider the EG6000XP and compare features you want with the prices. If you know you need more than 6000W output, hard to beat the price of a dependable pair of older MPP6548's (the 250v PV input ones).

 

[12VoltInstalls]

The low frequency version is the LVX 6048 - even higher standby consumption, but you will avoid mostly buy shutting off when not in use.

The LVX6048 was what I was referring to.
One might do it- if not a second parallel unit could be employed.
But it’s 120/240

For your shop set up: do you need 240volt?

I would for the big compressor and the Primeweld TiG 225.

never tried this

I currently have a 1012LV on the wall with the inverter off. I use the SCC daily and its 60A charger fed from the generator occasionally.

If you know you need more than 6000W output, hard to beat the price of a dependable pair of older MPP6548's (the 250v PV input ones).

Ya. The LVX, however, has some advantages especially if 6000W covers me.