I downloaded and re-viewed the installation instructions for this multimeter. It does say that the wattmeter sensor wires (twisted pair) can be extended up to 25 feet!
The polarity of the wires isn't an issue for the amperage reading but is for the watt reading. It says that if you install it and the amps reads ok but the watts doesn't then reverse the polarity of the wires on the back of the multimeter. It also confirmed that the twisted pair (as I suspected) is used to limit RF (radio frequency) electric noise that can interfere with other systems.
Good luck and be careful with the deadly voltages/currents on the 220 VAC system.
