- Thread starter Poggle
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Hello Poggle,
as long as it of adequate size there is no problem with a 10 metre one or longer for that matter. Generally the shorter the better but there is quite a bit of leeway.
The important thing is the load you are putting on it and the size of the cable.
Alec
as long as it of adequate size there is no problem with a 10 metre one or longer for that matter. Generally the shorter the better but there is quite a bit of leeway.
The important thing is the load you are putting on it and the size of the cable.
Alec
chunkolini
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And dont keep the cable coiled while working or it can melt.
It does not need miles to make a difference.
Each meter of cable has a resistance so lowers the voltage slightly, that increases the amperage as the wattage has stayed the same. As it is the amperage that matters when calculating the cable size / length its a double whammy effect as then the next meter has more amps to deal with ad infinitum.
Keep the cable as short as is practical or use much thicker cables.
That said 10m is not going to make much difference unless the load is very large or the cable very thin & you already have a low incoming voltage.
Just remember to always uncoil all of the extension before use.
Each meter of cable has a resistance so lowers the voltage slightly, that increases the amperage as the wattage has stayed the same. As it is the amperage that matters when calculating the cable size / length its a double whammy effect as then the next meter has more amps to deal with ad infinitum.
Keep the cable as short as is practical or use much thicker cables.
That said 10m is not going to make much difference unless the load is very large or the cable very thin & you already have a low incoming voltage.
Just remember to always uncoil all of the extension before use.
brightspark
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u havent stated what load u intend to use the lead on and what size the cable is , most leads would be max 1.5mm but u could make your own up using 2.5mm cable at 10m length
Have been using my arc welder with the reel for months now with no problems. Just couldn't see what difference using a Mig welder would have.
Cheers to you all for the replies
john
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No. The increased resistance reduces the current because the supply voltage stays constant so the power the load can take is reduced.
With motors this can mean a reduction in speed which reduces the back emf, this can lead to the current increasing and damaging the motor and/or the cable.
The conductors within a cable, whether an extension cable or not, have resistance which increases proportionally with length and decreases as 1/diameter squared. When current is drawn, a voltage is induced across the resistance of the cable resulting in the voltage at the end distant from the supply to decrease by an amount equal to the voltage developed across the resistance. The greater the current, the greater the voltage drop. Depending on it's design, some equipment will work less well e.g. a kettle will take (slightly) longer to boil when fed via a long extension lead. Other equipments, especially those using a switched mode power supply e.g. most if not all inverter welders, for a given welding current, will draw more current from the supply as the supply voltage drops, exacerbating the situation.
Following on from this, the current passed and voltage developed will lead to power being dissipated by the cable (Watts = Vdrop x current). "Laid flat" 1.5mm2 cable will get noticeably warm when a 3kW load is connected to it, so much so that leaving such an extension lead still coiled will probably eventually lead to the insulating material melting followed by the almost inevitable flash and puff of smoke!! There was a recent thread on this forum featuring one such extension that had gone up in smoke after being used to supply a 2kW radiant heater.
Following on from this, the current passed and voltage developed will lead to power being dissipated by the cable (Watts = Vdrop x current). "Laid flat" 1.5mm2 cable will get noticeably warm when a 3kW load is connected to it, so much so that leaving such an extension lead still coiled will probably eventually lead to the insulating material melting followed by the almost inevitable flash and puff of smoke!! There was a recent thread on this forum featuring one such extension that had gone up in smoke after being used to supply a 2kW radiant heater.
Hello Justme,
"Each meter of cable has a resistance so lowers the voltage slightly, that increases the amperage as the wattage has stayed the same. As it is the amperage that matters when calculating the cable size / length its a double whammy effect as then the next meter has more amps to deal with ad infinitum."
No that's not quite right, the wattage of an appliance is variable depending on the voltage applied and current drawn. The quoted wattage is at rated voltage and current.
If the voltage is lower then the current also drops and the wattage being the product of the two drops also. Motors if supplied with a reduced voltage tend to increase current if loaded because they slow down and their generated voltage (Back EMF) also
drops meaning they draw more current.
Alec
"Each meter of cable has a resistance so lowers the voltage slightly, that increases the amperage as the wattage has stayed the same. As it is the amperage that matters when calculating the cable size / length its a double whammy effect as then the next meter has more amps to deal with ad infinitum."
No that's not quite right, the wattage of an appliance is variable depending on the voltage applied and current drawn. The quoted wattage is at rated voltage and current.
If the voltage is lower then the current also drops and the wattage being the product of the two drops also. Motors if supplied with a reduced voltage tend to increase current if loaded because they slow down and their generated voltage (Back EMF) also
drops meaning they draw more current.
Alec
The practical answer is that your 135 Amp Rhyas Turbo should be okay on a 5 to 10 metre 1.5 mm cable, unless you run it flat out for long periods, or forget to uncoil the cable, as already pointed out several times.
But as Brightspark suggested, if it's any longer than 10 metres, look to change the cable for something like arctic caravan cable at 2.5mm. I have my 150 Amp Clarke on the end of a 15 metre 2.5mm arctic cable when welding down the garden sometimes, and it runs just fine, even on full power.
But as Brightspark suggested, if it's any longer than 10 metres, look to change the cable for something like arctic caravan cable at 2.5mm. I have my 150 Amp Clarke on the end of a 15 metre 2.5mm arctic cable when welding down the garden sometimes, and it runs just fine, even on full power.
Thanks for that Keith. I will get one of those. I don't need much more than 15 metres at home.
John
