Keithley 2790, Reference Manual

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Model 2790 SourceMeter
®
Switch System Reference Manual 3-3
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The 7702 module is safe to use with the 500V source of the 7751/7753 module.
The V-source is energy limited and classified as a non-hazardous source per
EN61010.
High energy circuit safety precautions
To optimize safety when measuring voltage in high energy distribution circuits, read and
use the directions in the following warning.
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Dangerous arcs of an explosive nature in a high energy circuit can
cause severe personal injury or death. If the multimeter is connected to
a high energy circuit when set to a current range or low resistance
range, the circuit is virtually shorted. Dangerous arcing can result even
when the multimeter is set to a voltage range if the minimum voltage
spacing is reduced in the external connections.
As described in the International Electrotechnical Commission (IEC)
Standard IEC 664, the Model 2790 is Installation Category I and signal
lines must not be directly connected to AC mains.
When making measurements in high energy circuits, use test leads that meet the following
requirements:
• Test leads should be fully insulated.
• Only use test leads that can be connected to the circuit (e.g., alligator clips, spade
lugs, etc.) for hands-off measurements.
• Do not use test leads that decrease voltage spacing. These diminish arc protection
and create a hazardous condition.
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For the front panel inputs, the maximum common-mode voltage (volt-
age between INPUT LO and the chassis ground) is 500V peak. For a
7702 module, the maximum common mode voltage is 300V. Exceeding
these values may cause a breakdown in insulation, creating a shock
hazard.
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The 7702 module is safe to use with the 500V source of the 7751/7753 module.
The V-source is energy limited and classified as a non-hazardous source per
ENG1010.
Use the following sequence when testing power circuits:
1. De-energize the circuit using the regular installed connect-disconnect device, for
example, by removing the device's power cord or by turning off the power switch.