Device for welding electrofusion fittings with extension cable

A method for keeping a voltage or a current constant during a welding process of an electrofusion fitting with a device for welding of the electrofusion fitting, the device using an extension cable, the method comprising:

• connecting the extension cable between a connection cable of a welding power supply and the electrofusion fitting to be welded;
• detecting the extension cable using the welding power supply;
• detecting data about the electrofusion fitting and recording the data about the electrofusion fitting to be welded using the welding power supply;
• determining a change in resistance of the extension cable by monitoring the resistance of the extension cable;
• autonomously supplying the current or the voltage with the welding power supply;
• autonomously regulating the current or the voltage based upon the detection of the connected extension cable, the determined change in resistance of the extension cable, and a resulting resistance due to the connected extension cable;
• and
• monitoring an instantaneous resistance of a heating wire winding in the electrofusion fitting during the welding process,
• wherein the current or the voltage is adjusted such that the current or the voltage remains constant during the welding of the electrofusion fitting,
• wherein the voltage or the current is regulated according to a change in the instantaneous resistance in the heating wire winding such that the voltage or the current remains constant throughout the welding process, and
• wherein monitoring the instantaneous resistance includes monitoring an output of a temperature sensor and calculating the instantaneous resistance based on the monitored output and the recorded data about the electrofusion fitting.