A switching device (28) comprising a primary switching block (30) including at least one semiconductor switch (34); and a switching control unit (32) to control the switching of the or each semiconductor switch (34). The switching device further includes a crowbar circuit (46) comprising a crowbar switch (56) switchable to selectively allow current to flow through the crowbar switch (56) in order to bypass the or each switching module; and a secondary switching block including a switching element (58) connected across a control electrode and a cathode of the crowbar switch (56). The switching element (58) is in communication with the switching control unit (32) to receive, in use, a control signal (66) generated by the switching control unit (32) when the primary switching block (30) is operating within predefined operating parameters.