a relay circuit for energizing a load in response to a control device and method of testing the relay circuit , in which a switch is provided for selectively disconnecting the control device from the relay circuit and activating a relay switch such that the load is energized when in a test mode and reconnecting the control device when in an operational mode . by disconnecting the control device in the test mode , the control device may be electrically isolated from the relay circuit thereby protecting the control device from damage due to backfeeding .