NFPA 70E uses the term “test instrument” and does not mention a digital multimeter, voltage detector, phase rotation meter or ammeter. There are test instruments that can only be used to measure voltage, such as a solenoid-type tester. Other devices may measure continuity, resistance, voltage or amp readings. 

Important safety note

When a qualified person makes contact with energized conductors or circuit parts with a test instrument to measure voltage, an arc flash hazard exists, as there are exposed energized conductors and circuit parts and the person is interacting with energized electrical equipment.

Training for qualified persons

NFPA 70E permits only qualified persons to use test instruments for tasks such as testing, troubleshooting and voltage measuring. These employees must be trained to select an appropriate test instrument. The training must include:

• A demonstration by the employee on how to use the test instrument to verify absence of voltage. 
• The limitations of each test instrument that might be used. For example, there are many documented incidents of unqualified persons using a test instrument rated at 600V on a 4,160V system. This misapplication typically results in an arc flash incident and serious injury.

Qualified persons must be trained on every test instrument they will use.

Ratings

Test instruments must be category rated. Test instruments for electricians in commercial and industrial venues must be rated CAT III or CAT IV. Test instruments must be properly rated, approved for the purpose and used in accordance with manufacturer instructions.

Inspection and verification

Before each use, test instruments and all associated test leads, cables, power cords, probes and connectors must be visually inspected for external defects and damage. When a test instrument is used to verify absence of voltage, the operation of the test instrument must be verified on any known voltage source before and after an absence of voltage test is performed.

Questions

• Can an unqualified person use test instruments?
• I am a qualified person. Do I need to be trained on the proper use and limitations of my digital multimeter to use it on the job?
• Is a phase rotation meter a test instrument?
• When using a test instrument to verify absence of voltage, what does NFPA 70E require?

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