Indoor current transformer cable KOLMA
Current transformers cable type KOLMA are suitable for the measurement of the sum of three-phase currents in a 3-phase cable.
A current transformer without primary conductor and primary insulation of its own, which can be mounted over an insulated cable or an insulated busbar.
Under normal operating conditions this sum is zero. In the event of an earth-fault the sum of the currents is equal to the earth-faul current and a corresponding current flows in the secondary.
These transformers are used together with static earth-fault relays. The cable current transformers can generally be used when measuring the residual current e.g. to prewarn of, or locate an earth-fault. An uninsulated busbar or low voltage cable serves as the primary conductor.
Highest voltage for equipment............ 0.72 kV
Primary current................................... max. 10 000 A
- Indoor dry type, cast resin insulated
- For measuring and protection
- Most electrical standards available