Apparatus, methods and systems are disclosed related to negotiation mechanism among control devices (200, 200a, 200b, 200c, 200d) each having a dedicated hierarchy level configured to obtain DC current from the control network (100) with at least a power source (300, 300′) on the network (100). The control device (200, 200a) with a higher dedicated hierarchy level may request another control device (200b, 200c, 200d) with a lower dedicated hierarchy level to release current for its use, when the available current at the power source (300, 300′) is not sufficient.