National Instruments NI 447 Series User Manual page 16

Chapter 1 Getting Started with the NI 447X
NI 447X User Manual
• Installation 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.
• Installation 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.
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