Chapter 1 Getting Started
NI PXI-8250 User Manual 1-4 ni.com
equipment, circuits powered by regulated low-voltage sources, and
electronics.
• Installation Category II is for measurements performed on circuits
directly connected to the electrical distribution system. This category
refers to local-level electrical distribution, such as that provided by a
standard wall outlet (for example, 115 AC voltage for U.S. or 230 AC
voltage for Europe). Examples of Installation Category II are
measurements performed on household appliances, portable tools, and
similar devices/modules.
• 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.