5
Making Measurements
Leakage current measurement
Single-phase 3-wire circuit
Ig
PE
Circuit breaker
Load
equipment
: Leakage current
3-phase 3-wire circuit
Ig
PE
PE
Circuit breaker
Load
equipment
: Leakage current
Other circuits
• Clamp around two wires together in a bundle in the single-phase 2-wire circuit.
• Clamp around four wires together in a bundle in the three-phase 4-wire circuit. Even when the
instrument cannot be clamped, you can measure leakage current using the ground wire of the
equipment instead.
IMPORTANT
• The instrument can momently display large a readout when you open and close the jaws;
however, this is not an error.
• The instrument cannot accurately make measurements in the following cases:
(1)
A large current flows through adjacent wires.
(2)
Special waveforms, such as that flowing through the secondary side of the inverter, is
measured.
(3) The jaws close incompletely. (In particular, if the external dimension of the object under
measurement is large, such as when the instrument is clamped around three-phase wires
together in a bundle, make sure that the jaws are closed completely. If the jaws are even
slightly open, measured values will include errors and the accuracy cannot be ensured.
HIOKI CM4001A963-00
Summary of Contents for CM4001
Page 2: ...HIOKI CM4001A963 00...
