Jim Phillips (brainfiller) wrote:
As part of establishing an electrically safe work condition, NFPA 70E permits the use of non-contact voltage instruments on systems above 1000 volts to test each phase conductor.
An informational note is also provided: for additional information on rating and design requirements for voltage detectors, refer to IEC 61243-1, Live Working — Voltage Detectors — Part 1: Capacitive type to be used for voltages exceeding 1kV a.c., or IEC 61243-2, Live Working — Voltage Detectors — Part 2: Resistive type to be used for voltages of 1kV to 36 kV a.c., or IEC 61243-3, Live Working — Voltage Detectors.
These standards fall under the IEC committee that I chair. According to IEC 61243-1, the presence of voltage shall not appear if the voltage to earth on the part to be tested is less than 10% of the nominal voltage. (not exactly absence of voltage)
The question:
Do you use non-contact voltage test instruments to verify ABSENCE of voltage?
Yes - with protective grounds
Yes - no grounds
No
Nothing above 1,000 volts
Your thoughts are encouraged and welcomed!
I believe the correct answer per NFPA 70E is No, for low volage systems direct-contact meters MUST be used, a non-contact could be used for initial checks but must be followed up by direct-contact. For Medium/ High Voltage, non-contact should be used.