4
Keysight M9164x and M9165x Startup and Service Guide
Most measurement, control, and data I/O signals are rated Measurement
Category I and must not be directly connected to mains voltage or to voltage
sources with high transient over-voltages. Measurement Category II connections
require protection for high transient over-voltages often associated with local AC
mains connections. Assume all measurement, control, and data I/O connections
are for connection to Category I sources unless otherwise marked or described in
the user documentation.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be
present on cable connector jacks or test fixtures. The American National
Standards Institute (ANSI) states that a shock hazard exists when voltage levels
greater than 30 Vrms, 42.4 Vpeak, or 60 VDC are present. A good safety practice
is to expect that hazardous voltage is present in any unknown circuit before
measuring.
Operators of this product must be protected from electric shock at all times. The
responsible body must ensure that operators are prevented access and/or
insulated from every connection point. In some cases, connections must be
exposed to potential human contact. Product operators in these circumstances
must be trained to protect themselves from the risk of electric shock. If the circuit
is capable of operating at or above 1000 V, no conductive part of the circuit may
be exposed.
Do not connect switching cards directly to unlimited power circuits. They are
intended to be used with impedance-limited sources. NEVER connect switching
cards directly to AC mains. When connecting sources to switching cards, install
protective devices to limit fault current and voltage to the card.
Before operating an instrument, ensure that the line cord is connected to a
properly-grounded power receptacle. Inspect the connecting cables, test leads,
and jumpers for possible wear, cracks, or breaks before each use.
When installing equipment where access to the main power cord is restricted,
such as rack mounting, a separate main input power disconnect device must be
provided in close proximity to the equipment and within easy reach of the
operator.
For maximum safety, do not touch the product, test cables, or any other
instruments while power is applied to the circuit-under-test. ALWAYS remove
power from the entire test system and discharge any capacitors before connecting
or disconnecting cables or jumpers, installing or removing switching cards, or
making internal changes, such as installing or removing jumpers.
