The line isolation monitor
shall be designed to have sufficient internal impedance such that, when properly connected to the isolated
system, the maximum internal current that can flow through the line isolation monitor
, when any point of the isolated
system is grounded
, shall be 1 mA.
Exception: The line isolation monitor shall be permitted to be of the low-impedance type such that the current through the line isolation monitor, when any point of the isolated system is grounded, will not exceed twice the alarm threshold value for a period not exceeding 5 milliseconds.
Informational Note: Reduction of the monitor hazard current, provided this reduction results in an increased "not alarm" threshold value for the fault hazard current, will increase circuit capacity.