A 1472, A1579 Leakage current clamp
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4.5 Other important current clamp parameters
4.5.1 High measuring range
Leakage clamps with a high measuring range can be used for other
applications too. A 20 A measuring range will cover most of application in
standard residential electrical installations. A 200 A will cover industrial
applications too.
4.5.2 Clamp diameter
In general a diameters of about 40mm is enough. For some applications a
higher diameter would be useful. A slimmer design of the current sensor
will be beneficial in most of applications.
4.5.3 Protection category
Overvoltage protection
Take care above the overvoltage category of the clamp. For use in offices,
residential, industrial, domestic sites at least 300V CAT III is preferred.
For use in power utility sites 600V CAT III (300V/ CAT IV) is obligatory.
Use on uninsulated conductors
Current clamps marked with the
sign have additional protection and
can be used for measuring on uninsulated conductors.
Current clamps without this sign or the
sign can be used only on
isolated conductors !
Note
The overvoltage category upstream the main fuses is usually CAT IV !
Refer to METRELs white paper
Electrical installation testers: CAT IV or
CAT III?
for more information.
