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// CODE SNIPPET

(2) Impedance

National Electrical Code 2020 of Minnesota > 5 Special Occupancies > 517 Health Care Facilities > 517.160 Isolated Power Systems > (B) Line Isolation Monitor > (2) Impedance
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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.

Related Code Sections


(2) Special Occupancies, Impedance
The line isolation monitor shall be designed to have sufficient internal impedance such that, when properly connected to the isolated system ...
National Electrical Code 2020 of Minnesota > 5 Special Occupancies > 517 Health Care Facilities > 517.160 Isolated Power Systems > (B) Line Isolation Monitor > (2) Impedance
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