L And T Energy Meter is those metre that allows the entire current to flow through it. This metre typically ranges from 0 to 100 amps. If one has ever worked with CTs (Current Transformers), one will notice that it is available in small sizes that fit almost any place in the 0 100 Amp range. Consequently, the CT for this energy metre is located inside the metre. In other words, in order to compute energy units, the whole current must flow through the energy metre, which is why these energy metres is also known as WC (Whole Current) metres.