Invertor extension doubts?

[cumbriasteve]

I have a decent MMA, not a Chinese cheapie and have been asked to do some welding ( 3.2 rods) at a location where the power is supplied by normal 2.5mm grey cable run from the house approx 20 metres away, think it's through the breaker for the cooker circuit 30amp?

I class this as an extension and not being electrically skilled have read about voltage drop, blowing capacitors and damaging equipment etc etc.

Opinions from the more experienced electrickery folks appreciated.

 

[chriskelland]

I regularly use my Inverter Fusion 160 on the end of up to 40 metres of extension lead without any problems, though only at around 80-90 amps. Using a couple of extra long caravan leads (think they are 2.5 sq mm flexible) with 16 amp connectors from a 13 amp socket.

We have used both MA160s on long leads at the same time with no problems.

Chris.

 

[rich r]

You're going to using less than 13A for 3.2mm rods, which is well within the limits of 2.5mm cable. There won't be much voltage drop at all over that distance either, so I wouldn't worry.

 

[cumbriasteve]

Cheers guys, My main concern was the very first time I used the MMA was at the same location and a capacitor blew within 5 mins, the machine was replaced without a problem and the fault put down to 'one of those things' that can happen.

 

[SiPMerlin150]

I've just wired up a 5 meter length of 2.5mm cable for my 150 amp buzzbox, set up with 15 amp fuses, and on full whack it has not blown a fuse at all,

But before that i had it on a heavy duty extension cord and 13 amp fuses, and any more than half power and it would pop the fuse in the extension.

This 2.5mm grey cable is rated at 27 amps and so there shouldn't be any issues of your inverter not being able to recieve the power it requires.

I'm guessing that my buzzbox must draw around 14 amps because theres days where i can crank up the power and its ok, and some days it would pop 2 or 3 fuses in 10 minutes, so now its 15 amps and all is fine!

 

[cumbriasteve]

I've just wired up a 5 meter length of 2.5mm cable for my 150 amp buzzbox, set up with 15 amp fuses, and on full whack it has not blown a fuse at all,

But before that i had it on a heavy duty extension cord and 13 amp fuses, and any more than half power and it would pop the fuse in the extension.

This 2.5mm grey cable is rated at 27 amps and so there shouldn't be any issues of your inverter not being able to recieve the power it requires.

I'm guessing that my buzzbox must draw around 14 amps because theres days where i can crank up the power and its ok, and some days it would pop 2 or 3 fuses in 10 minutes, so now its 15 amps and all is fine!

Yes I had no problems with my buzzbox and even my 235 MIG at home is working on normal supply so blowing fuses was never going to be an issue.

I think my main concern was some sort of fluctuating supply or voltage drop affecting the electronics of the invertor..thats my uneducated worry anyways.

Seems they have something that can compensate for that so I am probably concerned for no reason...fingers crossed

 

[SiPMerlin150]

Yes I had no problems with my buzzbox and even my 235 MIG at home is working on normal supply so blowing fuses was never going to be an issue.

I think my main concern was some sort of fluctuating supply or voltage drop affecting the electronics of the invertor..thats my uneducated worry anyways.

Seems they have something that can compensate for that so I am probably concerned for no reason...fingers crossed

I think voltage drop wouldn't occur on a 2.5mm cable, unlike on a smaller domestic cables, its like for instance trying to blow as hard as you can down a thin drinking straw, you'll go red in the face, then blowing down a cardboard tube 1 inch in diameter, much easier! (same thing for electricity)

 

[madkayaker]

Voltage drop does accrue on 2.5mm (as it does on all conductors) it doesn't sound the best of set ups and twin and earth is not for use as a flex only as a fixed install. Might be better to get some decent sized flex (2.5mm or 4mm) a roll of blue artic should be £70?

 

[cumbriasteve]

Voltage drop does accrue on 2.5mm (as it does on all conductors) it doesn't sound the best of set ups and twin and earth is not for use as a flex only as a fixed install. Might be better to get some decent sized flex (2.5mm or 4mm) a roll of blue artic should be £70?

Yes I suggested that to him last year, trouble is he is a tight fisted sod and only requires the very rare welding job... 3 small jobs in the last 7 years.

 

[oilcooled :)]

my parweld is a disaster on extension cables, was fit to drive across it with the new holland i gt so peeved off with it

 

[decepticon]

regularly use my weco inverter on the end of 40m of 2.5mm extensions at 110amps without problems. machines probably have different efficiencies and behave differently.
cant imagine there would be any noticable voltage drop on 40m of extension lead, afterall the electricity has probably just travelled hundreds of miles to get to your house, more likely loss of current. may be wrong though

 

[Robotstar5]

cant imagine there would be any noticable voltage drop on 40m of extension lead, afterall the electricity has probably just travelled hundreds of miles to get to your house

only the last few miles is at 230V and in much bigger cable

volt drop would be about 10V (4%) in a 40m lead

 

[rich r]

the electricity has probably just travelled hundreds of miles to get to your house, more likely loss of current. may be wrong though

It's travelled hundreds of miles true, but at significantly higher voltage and lower current, only stepped down to 230V generally well within a mile of your house. Then carried by cable larger than 2.5mm2 cable to your house itself.

But at the sort of currents used to weld with 3.2mm or smaller rods, you're only using 10-15A, which is well within the capabilities of 2.5mm2 cable for a few tens of metres without losing too much voltage due to the resistance of the wire.