Statguard Flooring - Questions And Answers

Should I wear ESD protection when working on or near energized equipment that is sensitive to ESD damage? Note: ESD sensitive components are commonly in the vicinity of (although commonly shielded from)very high voltage and dangerous circuits which must be accessed for measurements and adjustments. -Dave, Charlottesville, Va

This is a common question among practitioners of ESD control and users of "high voltage" apparatus.

Answer #139: The safety of the technician or engineer always comes first. If the person is bonded to ground through a 1 megohm resistor, then UL considers this safe up to 250 VAC. Any AC voltages greater than 250 Volts should be considered "high voltage" and the appropriate steps should be taken to protect the operator. An insulated platform and no other connection to ground, an operator is in a safer position than if he/she were grounded and working on high voltage. If in doubt, always favor the safety of the person when working with live power greater than 250 VAC. The DOD-HDBK-263 refers the MIL-STD-454 which states that the maximum current an operator should receive is less than 1 milliamp AC or 4 milliamp DC.

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