A hydraulic power control circuit for a construction vehicle, having a control section comprising: a first control valve connectable to a source of hydraulic fluid under pressure (P1, P2, LSP) to control a power actuator of the vehicle; a second control valve connectable to the source of hydraulic fluid under pressure (P1, P2, LSP) to control a hydraulic auxiliary equipment (C, H) via a first line associated to a first effect of the equipment (C, H), the equipment being either a single effect equipment or a double effect equipment; an interconnection downstream of the second control valve so that the first and the second control valves (1, 2) are operable, when both switched from the neutral position, to connect the actuator to the source of fluid under pressure (P1, P2, LSP) so as to control only one effect of the actuator by a flow-summation of the flow from the first and the second control valve (1, 2); a switch valve intercepting the interconnection and a second line to control the equipment (C, H); wherein the switch valve is operable either to discharge the second line for operation of the single effect equipment in a single effect mode and feed of the actuator via the interconnection; or to close the interconnection and feed the second line via the second control valve and the source of fluid under pressure (P1, P2, LSP) for operation of a second effect of the double effect equipment in a double effect mode; said control circuit being characterized in that a piloting section is provided to switch the switch valve and the first and the second control valves (1, 2) based on user's hydraulic command signals, the piloting section comprising a pilot switch valve operable in: a first position to simultaneously switch the first and the second control valves (1, 2) such as to feed the only one effect of the actuator by the source of fluid under pressure (P1, P2, LSP) via the interconnection; and a second position where the first and the second control valves (1, 2) are independently switchable one from the other to independently control the actuator and the equipment (C, H); the pilot switch valve being switched in the second position by a shuttle valve either upon receiving a first hydraulic command signal for actuation of the first effect of the double effect equipment from a first piloting line or upon receiving a second hydraulic command signal for actuation of the second effect of the double effect equipment from a second piloting line, the second hydraulic command signal being transmitted to the switch valve via a junction of the piloting section so as to cause the feed of the second line by the source of fluid under pressure. a first control valve connectable to a source of hydraulic fluid under pressure (P1, P2, LSP) to control a power actuator of the vehicle; a second control valve connectable to the source of hydraulic fluid under pressure (P1, P2, LSP) to control a hydraulic auxiliary equipment (C, H) via a first line associated to a first effect of the equipment (C, H), the equipment being either a single effect equipment or a double effect equipment; an interconnection downstream of the second control valve so that the first and the second control valves (1, 2) are operable, when both switched from the neutral position, to connect the actuator to the source of fluid under pressure (P1, P2, LSP) so as to control only one effect of the actuator by a flow-summation of the flow from the first and the second control valve (1, 2); a switch valve intercepting the interconnection and a second line to control the equipment (C, H); wherein the switch valve is operable either to discharge the second line for operation of the single effect equipment in a single effect mode and feed of the actuator via the interconnection; or to close the interconnection and feed the second line via the second control valve and the source of fluid under pressure (P1, P2, LSP) for operation of a second effect of the double effect equipment in a double effect mode; a first position to simultaneously switch the first and the second control valves (1, 2) such as to feed the only one effect of the actuator by the source of fluid under pressure (P1, P2, LSP) via the interconnection; and a second position where the first and the second control valves (1, 2) are independently switchable one from the other to independently control the actuator and the equipment (C, H); the pilot switch valve being switched in the second position by a shuttle valve either upon receiving a first hydraulic command signal for actuation of the first effect of the double effect equipment from a first piloting line or upon receiving a second hydraulic command signal for actuation of the second effect of the double effect equipment from a second piloting line, the second hydraulic command signal being transmitted to the switch valve via a junction of the piloting section so as to cause the feed of the second line by the source of fluid under pressure.