Section 6.3.4.1 of NFPA99 addresses Maintenance and Testing of the Electrical System. Section 6.3.4.1.4 of NFPA99 states The LIM circuit shall be tested at intervals of not more than 1 month by actuating the LIM test switch. For a LIM circuit with automated self-test and self-calibration capabilities, this test shall be performed at intervals of not more than 12 months. Actuation of the test switch shall activate both visual and audible alarm indicators.