Another inverter welder died today!

[premmington]

Welder arrived today!

Added a 16amp plug and some 16mm leads we had already.

Run a few passes on some very thin sheet metal with (Elga Cromarod 316LP 1.6mm x 250mm electrodes) between 18 and 35 amps DC

Also tried one 6013 3.2mm at 120amps on some thick plate.

Very pleased with the results.

 

[Jim Davey]

Just make sure your supply cables are up to the job. Poor (under voltage) power from long undersized extension cables is the number one killer of inverters.

 

[premmington]

Just make sure your supply cables are up to the job. Poor (under voltage) power from long undersized extension cables is the number one killer of inverters.

Thanks for the advice... Yes volt drop is a problem! There is another long standing post on this forum, where they contributors can't accept that fact.

But yes you are right!

 

[Jim Davey]

I get it all the time but it's a proven fact with inverters and I've been working with them for over 15 years so I think I can talk with a little bit of experience on this subject.

 

[wheresmejumper]

Obviously the design and quality of the welder dictates what length extension cable they can run on.probably urinating into the wind here again.....
ewm picotig,and lorch 160,both mentioned and recommended here already,can operate on 40% below regular supply voltage.thats about 138v
that equates to lots of metres of 3x1.5mm supply cable,and even more of 3x2.5mm cable.
Cheaper inverters are normally rated to around 10% less than normal voltage.

 

[Bill Edwards]

On that train of thought, for those who often have to work using long cables it probably wouldn't be difficult to fix a voltmeter to their welder so they could verify the supply is OK while using it.

 

[Jim Davey]

Doesn't mean it does them any good though. I know a distributor who shall remain nameless that managed to allow over 20 EWM Pico 162MVs to be blown up by supplying them with 3 kva transformers and long 16 amp 110volt extension leads trying to run 3.25 electrodes, this happened over a two month period over two or three large clients.
Now that's a good machine, and I listen and make sure I read the damn reccomended requirements when it comes to supply voltage AND current.
If you want a machine to do the same job on 110 volt that it can easily do on 240, you have to up the supply current. Because it's this simple, you half the supply current, you have to double the amperage to get the same output from the machine.
That's why I put my Picos out with a 32 amp extension that's 6mm squared if I'm going over 20 metres and it runs off a 5 kva transformer, and yes it's heavy, and yes, it's expensive, but I can count on two fingers the amount of my own Picos have died out in the field, and both of them were from being dropped.
Can't say the same for my Kemppi Minarc 151 that lasted all of two rods before being run flat out off 40 metres of skinny 16 110 volt cable melted the input filter PCB.
So voltage alone isn't the only factor at at play here.

 

[premmington]

Interesting subject this...

I tend to use a towable diesel set for site work!

 

[Jim Davey]

Well that's one way to avoid power supply issues lol

 

[Bill Edwards]

So voltage alone isn't the only factor at at play here.

When you say that, using very restrictive supplies and cables must cause huge voltage drop under load?
So, if you had a voltmeter wired into the inverter and strike the arc then you would see the voltage under load. So, using your example of people running long 16a cables off small transformers I would expect the working voltage must be dropping as the cables and supply can't handle the current. With no load you'd see the voltage it should be, but it would never be sustained when welding.

So, a voltmeter might show the 110v dropping to say 80 volts due to current restrictions, and hence failures.

 

[brightspark]

higher the voltage the lower the amperage . lower the voltage higher the amperage . just buy heavy leads if u dont want to calculate the voltage drop to see what csa cable u need

 

[Jim Davey]

Not to be a pedant but I think you mean halve the supply VOLTAGE double the amperage (current being measured in amps)

Sites are horrible for daisy chained 1.5mm2 leads, some at well over 50 metres...

Yeah thats what I meant, it's been a long week. Half the voltage, double the current.
Thanks for helping me out there friend.

 

[wheresmejumper]

Doesn't mean it does them any good though. I know a distributor who shall remain nameless that managed to allow over 20 EWM Pico 162MVs to be blown up by supplying them with 3 kva transformers and long 16 amp 110volt extension leads trying to run 3.25 electrodes, this happened over a two month period over two or three large clients.
Now that's a good machine, and I listen and make sure I read the damn reccomended requirements when it comes to supply voltage AND current.
If you want a machine to do the same job on 110 volt that it can easily do on 240, you have to up the supply current. Because it's this simple, you half the supply current, you have to double the amperage to get the same output from the machine.
That's why I put my Picos out with a 32 amp extension that's 6mm squared if I'm going over 20 metres and it runs off a 5 kva transformer, and yes it's heavy, and yes, it's expensive, but I can count on two fingers the amount of my own Picos have died out in the field, and both of them were from being dropped.
Can't say the same for my Kemppi Minarc 151 that lasted all of two rods before being run flat out off 40 metres of skinny 16 110 volt cable melted the input filter PCB.
So voltage alone isn't the only factor at at play here.

I wasnt aiming that urine at you Jim
yes agree with what your saying.newarc even put 32amp only stickers on their dual voltage machines to help avoid user error.

 

[dannyp]

something else i found with sites, the transformers at the end of the cabel.

the ye typical 15 KVA metal boxes seem to have 4x 16A outputs that everyone use's and are often triping out, and a pair of 32A outputs that no one ever seems to use. often wonderd if they are on a diffrent set of windings as thigs allways seem to go better on them.

sites are terrible for power distrobuton, espetaly the ones where there is a ban on anything 240v you have the 110v power points provided and thats it. then the extension leads get stupid length. even the 9" grinder normaly lets it be know it's unhappy

 

[dannyp]

it the only downside with inverters i think, (the terms won't be quite correct here.) but with an inverter when you set the output current it's basicly settign the power requirement. and they will provide that output or blow up trying. as the suply voltage drops they draw more current, more current they pull the more the voltage drops

 

[brightspark]

the reason the 30 amp dont get used is the plugs are larger and everyone has the 16 amp ones . and as far as the trippings concerned its obvious why it dont trip . its double the breaking capacity

 

[Jim Davey]

Facepalm

 

[dannyp]

the reason the 30 amp dont get used is the plugs are larger and everyone has the 16 amp ones . and as far as the trippings concerned its obvious why it dont trip . its double the breaking capacity

so everyone is busy chaing 16A leads and splitters into every avalible 16A outlet. im pritty sure some of them have a 32A baecker covering 2x16a outlets and on 32a per 32a outlet

anyway 32A leads are optimal ( then a 32A-16A ) no bother finding power then

 

[brightspark]

so everyone is busy chaing 16A leads and splitters into every avalible 16A outlet. im pritty sure some of them have a 32A baecker covering 2x16a outlets and on 32a per 32a outlet

anyway 32A leads are optimal ( then a 32A-16A ) no bother finding power then

probably and no ones noticed

 

[wheresmejumper]

the the 30 amp dont get used is the plugs are larger and everyone has the 16 amp ones . and as far as the trippings concerned its obvious why it dont trip . its double the breaking capacity

The best ive seen,is a plumber was out of 110v yellow extensension leads,but had a blue 220v lead.ground the stubs off etc and ran what was a blue 110 supply across the site.
safety officer ran out of office glowing bright red about to sack people left right and centre when he saw the '220' lead.after it was explained to him,he still couldnt get his head around it.but its blue,its 220!idiot.
the plumber got yellow marking paint and sprayed the cable.that threw him further off track.