A system for combining power to a load in a Powered Device, PD, using Power Over Ethernet, PoE, the system being adapted for receiving at least four pairs of wires from at least one Power Sourcing Equipment, PSE, the four pairs of wires comprising a first channel of two of the pairs of wires (44, 45) and a second channel of the other two pairs of wires (46, 47), each pair of wires carrying a common mode voltage, the first channel supplying first voltages across the two pairs of wires, and the second channel supplying second voltages across the other two pairs of wires, the system comprising: an active bridge comprising controllable bridge switches (90, 92, 94, 96, 126, 128, 136, 138), a first set of the bridge switches (90, 92, 94, 96) being connected to the first channel for coupling the first voltages to the load, a second set of the bridge switches (126, 128, 136, 138) being connected to the second channel for coupling the second voltages to the load; the system being characterized in that it further comprises: a first controller circuit comprising an active bridge controller circuit and a first interface controller circuit, the active bridge controller circuit controlling conduction of the first set of bridge switches (90, 92, 94, 96) and the second set of bridge switches (126, 128, 136, 138), the first interface controller circuit containing a first PoE handshaking circuit (112, 114) to ensure the PD is compatible with the at least one PSE; a detector configured to detect the coupling of the first voltages to the load by a series switch controlled by an external second PoE handshaking circuit (100, 102); and a control circuit configured to carry out the following routine: a) controlling the first set of bridge switches (90, 92, 94, 96) to be on to couple the first voltages supplied by the first channel to the load only after it has been detected that the series switch has been turned on to couple the first voltages to the load; and b) after step a, performing a PoE handshaking routine by the first PoE handshaking circuit (112, 114) via the second channel with the at least one PSE and, upon a successful PoE handshaking routine performed by the first PoE handshaking circuit (112, 114), controlling the second set of bridge switches (126, 128, 136, 138) to be on to couple the second voltages to the load, such that power from the first channel and power from the second channel are combined to provide power to the load. a first controller circuit comprising an active bridge controller circuit and a first interface controller circuit, the active bridge controller circuit controlling conduction of the first set of bridge switches (90, 92, 94, 96) and the second set of bridge switches (126, 128, 136, 138), the first interface controller circuit containing a first PoE handshaking circuit (112, 114) to ensure the PD is compatible with the at least one PSE; a detector configured to detect the coupling of the first voltages to the load by a series switch controlled by an external second PoE handshaking circuit (100, 102); and a control circuit configured to carry out the following routine: a) controlling the first set of bridge switches (90, 92, 94, 96) to be on to couple the first voltages supplied by the first channel to the load only after it has been detected that the series switch has been turned on to couple the first voltages to the load; and b) after step a, performing a PoE handshaking routine by the first PoE handshaking circuit (112, 114) via the second channel with the at least one PSE and, upon a successful PoE handshaking routine performed by the first PoE handshaking circuit (112, 114), controlling the second set of bridge switches (126, 128, 136, 138) to be on to couple the second voltages to the load, such that power from the first channel and power from the second channel are combined to provide power to the load. a) controlling the first set of bridge switches (90, 92, 94, 96) to be on to couple the first voltages supplied by the first channel to the load only after it has been detected that the series switch has been turned on to couple the first voltages to the load; and b) after step a, performing a PoE handshaking routine by the first PoE handshaking circuit (112, 114) via the second channel with the at least one PSE and, upon a successful PoE handshaking routine performed by the first PoE handshaking circuit (112, 114), controlling the second set of bridge switches (126, 128, 136, 138) to be on to couple the second voltages to the load, such that power from the first channel and power from the second channel are combined to provide power to the load.