One important issue in the design and optimization of a superconducting cable conductor is the control of the current distribution between single tapes and layers. This presentation is based on a number of experiments performed on a 4-layer three meter long prototype superconducting cable conductor. The self and mutual inductances of the layers are studied theoretically, The current distribution between the superconducting layers is monitored as a function of transport current, The results are compared with the expected current distribution given by our equivalent electrical circuit model. The AC-losses are measured as a function of transport current and a given current distribution and compared with the monoblock model. Recommendations for design of future cable conductor prototypes are given.