B+K precision 9833B User Manual page 2

1 Safety Summary
The following safety precautions apply to both operating and maintenance personnel and must
be followed during all phases of operation, service, and repair of this instrument.
Before applying power to this instrument:
 Read and understand the safety and operational information in this manual.
 Apply all the listed safety precautions.
 Verify that the voltage selector at the line power cord input is set to the correct line
voltage. Operating the instrument at an incorrect line voltage will void the warranty.
 Make all connections to the instrument before applying power.
 Do not operate the instrument in ways not specified by this manual or by B&K Precision.
Failure to comply with these precautions or with warnings elsewhere in this manual violates the
safety standards of design, manufacture, and intended use of the instrument. B&K Precision
assumes no liability for a customer's failure to comply with these requirements.
Category rating
The IEC 61010 standard defines safety category ratings that specify the amount of electrical
energy available and the voltage impulses that may occur on electrical conductors associated
with these category ratings. The category rating is a Roman numeral of I, II, III, or IV. This rating
is also accompanied by a maximum voltage of the circuit to be tested, which defines the voltage
impulses expected and required insulation clearances. These categories are:
Category I (CAT I): Measurement instruments whose measurement inputs are not intended to
be connected to the mains supply. The voltages in the environment are typically derived from a
limited-energy transformer or a battery.
Category II (CAT II): Measurement instruments whose measurement inputs are meant to be
connected to the mains supply at a standard wall outlet or similar sources. Example
measurement environments are portable tools and household appliances.
Category III (CAT III): Measurement instruments whose measurement inputs are meant to be
connected to the mains installation of a building. Examples are measurements inside a
building's circuit breaker panel or the wiring of permanently-installed motors.
Category IV (CAT IV): Measurement instruments whose measurement inputs are meant to be
connected to the primary power entering a building or other outdoor wiring.
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