CSA C22.2-NO.204:2017 pdf download.Line isolation monitors
4.1.2.1 A line isolation monitor shall include the following indicators:
a) an alarm level indicator consisting of a red signal lamp and an associated audible alarm, both of which are energized except as specified in Clause 4.1.2.3 as long as the total hazard index equals or exceeds 5 mA, and may be energized as low as 85% of the total hazard index;
b) a green signal lamp that is energized as long as the red signal lamp is not energized; and a meter, which shall display the total hazard index and, at the alarm level, shall be accurate within +10%, -0%.
4.1.2.3 A monitor shall include a manually operable means to shut off the audible alarm, in accordance with the following:
a) the intended operation of the red signal lamp is not prevented;
b) a reduction in total hazard index that causes the green signal light to be re-energized shall also cause the manually operable means to be reset to the normal position or shall cause a distinctive audible or visible signal to indicate that the alarm has been silenced; and
c) a reduction in total hazard index that causes the green signal light to be re-energized shall also cause the manually operable means to be reset to the normal position. If the manually operable means requires manual resetting, a distinctive audible or visible signal shall indicate that the audible alarm is silenced until the manually operable means is reset to the normal position.
4.1.2.4 A monitor shall include a manually operable switch means to test it for proper operation, in accordance with the following:
a) it shall not be possible to leave the test switch in the test position;
b) the operation of the test switch shall disconnect the monitor circuitry from the grounding terminal of the monitor and shall connect it to a test impedance arrangement that is connected across the line terminals of the monitor and, at 85% of nominal system voltage, is capable of producing a total hazard index, of a value not less than that at which the monitor is intended to alarm; and
c) the operation of the test switch means of a normally functioning monitor shall cause
i) the green signal lamp to be de-energized;
ii) the red signal lamp to be energized;
iii) the audible alarm to be energized; and
iv) the meter to indicate a total hazard index not less than the alarm level.CSA C22.2-NO.204 pdf download.