Method and safety circuit for operating a photovoltaic device

The method involves short circuiting the photovoltaic devices (2) to supply current to the consumer device, when the photovoltaic devices are operated in specific operation mode during start-up period. The current generated by photovoltaic device is supplied to consumer device through suitable cables, in another operating mode. The control signal is transmitted through the cable to the safety circuit to change the operation mode of photovoltaic device. The control signal is transmitted by modulation of voltage pulse having frequency of 10-500 kHz with the pulse ratio of about 1:1-1:50. An independent claim is included for safety circuit for photovoltaic device.