Important Test System Safety Information - Keithley 708B Reference Manual

Section 4: Theory of operations

Important test system safety information

This product is sold as a stand-alone instrument that may become part of a system that could contain
hazardous voltages and energy sources. It is the responsibility of the test system designer, integrator,
installer, maintenance personnel, and service personnel to make sure the system is safe during use
and is operating properly.
You must also realize that in many test systems a single fault, such as a software error, may output
hazardous signal levels even when the system indicates that there is no hazard present.
It is important that you consider the following factors in your system design and use:
•
The international safety standard IEC 61010-1 defines voltages as hazardous if they exceed
30 V rms and 42.4 V peak or 60 V dc for equipment rated for dry locations. Keithley Instruments,
Inc. products are only rated for dry locations.
•
Read and comply with the specifications of all instruments in the system. The overall allowed
signal levels may be constrained by the lowest rated instrument in the system. For example, if
you are using a 500 volt power supply with a 300 V dc rated switch, the maximum allowed
voltage in the system is only 300 V dc.
•
Make sure any test fixture connected to the system protects the operator from contact with
hazardous voltages, hot surfaces, or sharp objects. This may be accomplished by shields,
barriers, insulation, safety interlocks, or the like.
•
Cover the device under test (DUT) to protect an operator from flying debris in the event of a
system or DUT failure.
4-2
Figure 74: Model 708B mainframe block diagram
100 - 240 VAC
50/60 Hz
AC Power
Entry and Fuse
LAN
USB
IEEE-488
Communication
Interfaces
Microprocessor
Digital I/O
TSP-Link
Relay
Power
Models 707B and 708B Switching Matrix Reference Manual
Universal
Power
Supply
Instrument
Power
Communication
and
Power
Board
Communication
and
Power
Power
Switch
Instrument
Backplane
Card Slot
Front Panel
of Instrument
Two-Line
VFD Display
and
LAN Status LED
Navigation
Wheel
707B-901-01 Rev. A / August 2010