5: Basic Digital Multimeter (DMM) Operation Series 3700 System Switch/Multimeter
-2 Document Number: 3700S-900-
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:
WARNING 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 Series 3700 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 (for example, 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.
Use the following procedure when testing power circuits:
1. De-energize the circuit using the regular installed connect-disconnect device. For example,
remove the device's power cord or by turning off the power switch.
2. Attach the test leads to the circuit under test. Use appropriate safety rated test leads for this
application. If over 42V, use double-insulated test leads or add an additional insulation
barrier for the operator.
3. Set the multimeter to the proper function and range.
4. Energize the circuit using the installed connect-disconnect device and make measurements
without disconnecting the multimeter.
5. De-energize the circuit using the installed connect-disconnect device.
6. Disconnect the test leads from the circuit under test.
To Next Page
Loading...
Need help?
General
