Abstract: Electric vehicle supply equipment has a test circuit configured to be switchable from a first test mode to at least a second test mode. In the first test mode, the test circuit is configured to measure a first voltage difference between a live terminal and a neutral terminal, a second voltage difference between the live terminal and a reference ground terminal and a third voltage difference between a circuit protective conductor terminal and the reference ground terminal and to disconnect a charging supply if at least one of the first, second and third voltage differences exceeds a respective voltage limit. In the second test mode, the test circuit is configured to measure the first voltage difference and to disconnect the charging supply if the first voltage difference exceeds a respective voltage limit and not to disconnect the charging supply in response to any test of the second or third voltage differences.