I have a Victron Current Sensor connected to a Quattro 15KVA inverter reading 4 small grid tie inverters connected to the AC Bus. The sensor is set to its highest reading to allow 7kw input. The color control is only showing about two thirds of the actual input. It has been working for 2 weeks now. Is there any way to calibrate it. It is reading 0w when there is no input.