Stanford Research Systems SR865A, Operation Manual

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Safety and Preparation For Use i
SR865A DSP Lock-in Amplifier
Safety and Preparation for Use
Warning
Dangerous voltages, capable of causing injury or death, are present
in this instrument. Use extreme caution whenever the instrument
covers are removed. Do not remove the covers while the unit is
plugged into a live outlet.
Line Voltage Selection
Caution
This instrument may be damaged if operated with the LINE VOLTAGE SELECTOR set
for the wrong ac line voltage or if the wrong fuse is installed.
The SR865A operates from a 100V, 120V, 220V, or 240V nominal ac power source
having a line frequency of 50 or 60 Hz. Before connecting the power cord, verify that the
LINE VOLTAGE SELECTOR card, located in the rear panel fuse holder, is set so that
the correct ac input voltage value is indicated by the white dot.
Conversion to other ac input voltages requires a change in the voltage selector card
position and fuse value. See Appendix F (page 177) for detailed instructions.
Line Fuse
Verify that the correct line fuse is installed before connecting the line cord. For
100V/120V, use a 1 Amp fuse and for 220V/240V, use a 1/2 Amp fuse. See Appendix F
(page 177) for detailed fuse installation instructions.
Line Cord
The SR865A has a detachable, three-wire power cord for connection to the power source
and to a protective ground. The exposed metal parts of the instrument are connected to
the outlet ground to protect against electrical shock. Always use an outlet which has a
properly connected protective ground. Power Cord
Grounding
A chassis grounding lug is available on the back panel of the SR865A. Connect a heavy
duty ground wire, #12AWG or larger, from the CHASSIS GROUND lug directly to a
facility earth ground to provide additional protection against electrical shock.
Grounded BNC shields are connected to the chassis ground. Do not apply any voltage to
the grounded shields. The A and B signal input shields are connected to chassis ground
through resistors and can tolerate up to 1 V of applied voltage.
GFCI (Ground Fault Circuit Interrupter)
GFCI protected outlets are often available in production and laboratory environments,
particularly in proximity
to water sources. GFCI’s are generally regarded as an important
defense against electrocution. However, the use of GFCI in conjunction with the SR865A