We have a unit Drok Digital AC Multimeter Voltmeter Ampmeter 80-300V 0-100Amp we bought on Amazon. The power is 240v and uses two lines and a ground. When we place the lines through the circle it reads only the voltage but not the amperage.<span id=”productTitle” class=”a-size-large”></span>
Is this device able to work with this setup? Or do we need to have to read each line separately?