Chapter1 Introduction
NI6013/6014 User Man ual 1-6 ni.com
Operate this product only at or belowthe installation category stated in
Appendix A, Specifications.
The followingis a description of installat ion categories:
•InstallationCategory I is for measurements performed on circuits not
directly connected to MAINS1. This categoryis a signal level such as
voltageson a printed wire board (PWB )on the second ary of an
isolation transformer.
Examplesof Installation Category I are measurements on circuits not
derivedfrom MAINS and specially protected (internal)
MAINS-derivedcircuits.
•Installation Category II is for measurements performed on circuits
directlyconnected to the low-voltage installation. This category refers
to local-leveldistribution such as that provided by a standard wall
outlet.
Examples of Installation Category II arem easurements on household
appliances, portable tools, and similar equipment.
•InstallationCategory III is for measurements performed in the building
installation.This category is a distribution level referring to hardwired
equipment that does not rely on standard building insulation.
Examples of Installation Category III include measurements on
distributioncircuits and circuit breakers. Other examples of
InstallationCategory III are wiring including cables, bus-bars, junction
boxes,switches, socket outlets in the building/fixedinstallation, and
equipmentfor industrial use, such as stationary motors with a
permanent connection to the building/fixedinstallation.
•Installation Category IVis formeasurement sperfo rmed at the source
of the low-voltage(<1,000 V) installation.
Examples of InstallationCategory IV are electric meters, and
measurements on primary overcurrentprotection devices and
ripple-control units.
1MAINSis defined as the electricity supply system to which the equipment concerned is designed to be connected either for
poweringthe equipment or for measurement purposes.