Application examples for alternating current


Risk of injury through electric shock and damage to the device!

Bring the Bus Terminals system into a safe, de-energized state before starting mounting, disassembly or wiring of the Bus Terminals!


Operate the current transformer as intended!

Please note that many manufacturers do not permit their current transformers to be operated in no-load mode! Connect the KL3403 to the secondary windings of the current transformers before using the current transformer!

Power measurement at a machine


Do not confuse current and voltage circuit!

Avoid confusing the current and voltage circuit during connection, since the direct connection of mains voltage to the terminal points for the current transformers (typical input resistance 33 mΩ) would destroy the power measurement terminal!

Application examples for alternating current 1:
Application example - power measurement at a machine
Application examples for alternating current 2:

Polarity of the current transformers

If negative power values are measured on a circuit, please check whether the associated current transformer circuit is connected correctly.

Current measurement on a motor


Make sure terminal point N is zeroed or grounded!

If you do not connect the terminal point N with the neutral conductor of your mains supply (e.g. if the KL3403 is used purely for current measurements), terminal point N should be earthed, in order to avoid dangerous overvoltages in the event of a current transformer fault!

Application examples for alternating current 3:
Application example - current measurement at a motor