My 120v breakers have both a black wire (Load Power) and white wire (Load Nuetral). Can I put the clamp over both wires or does it need to go only on the Load Power wire?
Sounds like you have Ground Fault or Arc fault breakers. The Vue2 clamps must only be installed over the black (hot) wires. If you clamp both the black and white (neutral wires), the positive and negative current flow will cancel and you will see zero power/current.