A retrofit Light Emitting Diode, LED, tube for use in a multi lamp luminaire lighting system arranged to be powered from a single high frequency electronic ballast, the retrofit LED tube comprising: - an LED array for emitting light; - a power rectifier (23, 24, 26, 27, 42-43, 52-53, 62-65) having an input and an output, wherein the power rectifier (23, 24, 26, 27, 42-43, 52-53, 62-65) is arranged to receive an AC supply voltage at its input, in use, to convert the AC supply voltage to a DC voltage, and to provide the DC voltage, via its output, to the LED array ; - a controllable switch circuit arranged to short circuit the LED array such that the LED array does not emit light; - a control unit arranged for wirelessly receiving a dimming command and for controlling the controllable switch circuit based on the received dimming command; - a storage capacitor placed in parallel over the LED array ; - a further rectifier having an input and an output, wherein the input of the further rectifier is connected to the output of the power rectifier (23, 24, 26, 27, 42-43, 52-53, 62-65), and wherein the output of the further rectifier is connected to the storage capacitor , wherein the further rectifier is arranged to prevent depletion of the storage capacitor when the controllable switch circuit is short circuiting the LED array , characterized in that : the storage capacitor is configured to supply power to the control unit , wherein the control unit is further arranged to: 1) determine that a voltage over the storage capacitor is below a predetermined depletion threshold; 2) based on the determination that the voltage is below a predetermined depletion threshold, temporarily controlling the controllable switch circuit not to short circuit the LED array such that the storage capacitor is able to charge. - an LED array for emitting light; - a power rectifier (23, 24, 26, 27, 42-43, 52-53, 62-65) having an input and an output, wherein the power rectifier (23, 24, 26, 27, 42-43, 52-53, 62-65) is arranged to receive an AC supply voltage at its input, in use, to convert the AC supply voltage to a DC voltage, and to provide the DC voltage, via its output, to the LED array ; - a controllable switch circuit arranged to short circuit the LED array such that the LED array does not emit light; - a control unit arranged for wirelessly receiving a dimming command and for controlling the controllable switch circuit based on the received dimming command; - a storage capacitor placed in parallel over the LED array ; - a further rectifier having an input and an output, wherein the input of the further rectifier is connected to the output of the power rectifier (23, 24, 26, 27, 42-43, 52-53, 62-65), and wherein the output of the further rectifier is connected to the storage capacitor , wherein the further rectifier is arranged to prevent depletion of the storage capacitor when the controllable switch circuit is short circuiting the LED array , characterized in that : the storage capacitor is configured to supply power to the control unit , wherein the control unit is further arranged to: 1) determine that a voltage over the storage capacitor is below a predetermined depletion threshold; 2) based on the determination that the voltage is below a predetermined depletion threshold, temporarily controlling the controllable switch circuit not to short circuit the LED array such that the storage capacitor is able to charge. 1) determine that a voltage over the storage capacitor is below a predetermined depletion threshold; 2) based on the determination that the voltage is below a predetermined depletion threshold, temporarily controlling the controllable switch circuit not to short circuit the LED array such that the storage capacitor is able to charge. <EOS>