newbie question - power consumption over 100m

[Rusty-Matt]

Hello

I am brand new to the forum and welding - I have two old cars both will need regular welding so am looking to learn to do it myself...

My question is pretty basic - our garage has mains power but is about 100 metres from the house.

Is there a test I can do to check I can draw sufficient power for a 150Amp welder over that distance, without plugging a welder in and seeing if it works.

The cable is 6mm, and I won't be doing intensive welding - so burning the cable out is not a real concern

If there is voltage drop at the far end under load would it damage the welder, or just not work optimally...?

Any advice gratefully received

 

[piman]

Hello Matt,

if my maths are correct you'll lose about 15 volts at a load of 20 amps over 100 metres (7.3mV x20 x100). If you start at 250 then you'll be down to 225 volts at the garage. I would think that would be OK for your welder but see what voltage specification it gives , e.g. 220 to 240v?

Alec

 

[Wendelspanswick]

All figures are approximate.

A 150amp mig will draw about 3.75 kW so 18 amps.
6mm PVC 3 core armoured buried underground for 100m will carry 33 amps so well within the limit.

A voltage drop of 11v.

https://www.tlc-direct.co.uk/Techni...30&length=100&submit=Calculate+Min+Cable+Size
The above calculator is really useful but you need to enter in more accurate data yourself to be sure.
Remember as well to factor in any other load that may be using the supply cable, if your welding at night you need to add lighting to the load as an example.

 

[Wendelspanswick]

Hello Matt,

if my maths are correct you'll lose about 15 volts at a load of 20 amps over 100 metres (7.3mV x20 x100). If you start at 250 then you'll be down to 225 volts at the garage. I would think that would be OK for your welder but see what voltage specification it gives , e.g. 220 to 240v?

Alec

Is that a typo, voltage loss of 15v but 250-15=235 not 225?

 

[Kent]

its not great and can damage some plants. You will get some variance in your supply to the house anyhow I recon as it sounds like a rural location

 

[mike 109444]

Some food for thought http://www.mig-welding.co.uk/forum/threads/urban-myth.38052/#post-420423
And welcome BTW

 

[piman]

Hello Wendelspanwick,

yes, but the answer was correct, it should have been 240 of course.

Alec

 

[normspanners]

ome food for thought http://www.mig-welding.co.uk/forum/threads/urban-myth.38052/#post-420423
And welcome BTW

As per meat loaf ---------Ya took the words right outta ma mouth ------- hopefully it wasnt when you where kissing me though !

 

[steviec_lj]

Bearing in mind voltage is supplied at 240 +/- 10% or something daft like that. Then there's demand during peak times. An allowance for lighting and other power tools.

Welding a car won't call for 150a though.

 

[normspanners]

I found it doesnt damage the welder it just takes the 'cream' off the top, the welder doesnt have it's sparkle ( pun intended btw)
liftting the voltage up brings it back.

 

[Rusty-Matt]

Thanks for all the input - I bought a Clarke 135TE (I know - not a serious welder) but is seems to do the trick and works fine regarding mains power.

Currently busy making lots of horrible welds on scrap - until I'm brave enough to tackle the car