Visual stories, solved problems.
"I would like to stretch the cables of my welding machine, what length would you recommend?"
Expensive this question is addressed that in itself is absolutely legitimate but provides a short and significant premise regarding the power of the welding machine in relation to its factor of use (in this regard, follow the video on How to read the cycle of use of a welding machine) The output voltage, the power made in relation to the electrode diameter and not least in importance, if the machine is connected to the socket or an electric extension. Naturally we start from the assumption that the system to which it is connected has 3 kW available and the welding machine is single-phase.
The nominal power of the machine is intended with the exit of the connector on which the mass cables and the electrode holder pliers are grafted. If it is deduced that the longer the cable is the greater the power drop, which also depends on the section.
We hypothesize, for example, a 16 mmq cable that has a capacity of 160 amps at 60% of use with a maximum temperature of 70 ° C. Each cable meter will a drop in the flow rate according to the parameters we mentioned.
Without forwarding the particular calculations that can be found safely on Google, even with useful tables that can be easily usable, with the spirit that distinguishes us and with the aim of providing useful and rapid information, We can prudentially say that every meter of cable, if well sized, has a power loss of about 2%.
As a result, if we set the machine at 100 amps and we have the cable 5 meters long, about 90 amps will arrive at the electrode that are the minimum to be able to weld the 2.5 mm diameter electrode.
Another important aspect, and we say above all to those who own old welders, is verifying the connection of the panel sockets. From one of our internal survey conducted over 20 years of experience, 90% of operating abnormalities is due to an unexplet closing of the electrical circuit due to poor flow rate, which is due to damaged cables or worn connections.
But let's go back to the initial question to try to give a quick, practical and useful answer.
For our part, we recommend, given the portability of the welding machine and the frequency with which we come across low quality construction products (not sold by us), to apply no more than 3-4 meters for the caliper and 2-3 meters for the mass.
The section depends on the power of the machine. Normally for a home welding machine is used 16 mmq or maximum 25 mmq. Superior lengths are possible? Certainly, but having the awareness that there will be greater absorption to equal surrender.
A last practical advice: if applied to a prolong, make sure that the cables are at least from section 3x2.5 and the extension cable is completely done to prevent it from overheating.