Fluke 39 User Manual page 59

Applications
Measure for excessive current (tripping of circuit breakers) and other general
measurements (such as level of current flow) in each circuit. Measure balance
between phases, neutral current and frequency, and harmonic distortion.
Measure input current, crest factor, and harmonics for PC, copier, printer,
and single phase UPS. Most electronic equipment loads are nonlinear due to
their use of switching-type power supplies.
Black
Red
a22f.eps
Figure 24. Receptacle Load Center (Neutral Current Measurement)
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