National Instruments NI 785xR User Manual
Page 21
Chapter 1
Introduction
© National Instruments Corporation
1-11
R Series Intelligent DAQ User Manual
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Measurement Category III is for measurements performed in the
building installation at the distribution level. This category refers to
measurements on hard-wired equipment such as equipment in fixed
installations, distribution boards, and circuit breakers. Other examples
are wiring, including cables, bus bars, junction boxes, switches, socket
outlets in the fixed installation, and stationary motors with permanent
connections to fixed installations.
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Measurement Category IV is for measurements performed at the
primary electrical supply installation (<1,000 V). Examples include
electricity meters and measurements on primary overcurrent
protection devices and on ripple control units.