Installation diagram of current switch in distribution box

A current switch is installed by mounting the split-core sensor over the conductor in the distribution box and connecting its dry-contact terminals to the monitoring circuit.

Placement and Mounting

The current switch, typically a split-core sensor, should be installed over the conductor you want to monitor. Open the sensor, place it around the live or phase conductor, and close it until it latches, ensuring the two halves are properly aligned. Dirt or misalignment can impair operation, so keep the sensor clean. The switch can be mounted in a suitable location inside the distribution box using the two mounting holes on its base .

Wiring Connections

• The current switch has two screw terminals for connection to the monitoring circuit.
• The output is a dry contact, normally open, which closes when the monitored current exceeds the trip value.
• The switch is not polarity sensitive, so either terminal can be connected to the control or alarm circuit .
• For increased sensitivity, the conductor can be looped multiple times through the sensor, but this reduces the maximum measurable current proportionally .

Integration with Distribution Box

In a typical single-phase distribution box setup:

1. The main supply (phase and neutral) enters the distribution board through a double-pole MCB or main switch .
2. The output of the main MCB is connected to an RCCB or RCD for protection against leakage currents .
3. From the RCCB, power is distributed to single-pole MCBs for individual loads such as lighting, sockets, or appliances .
4. The current switch is installed on the phase conductor of the circuit you want to monitor, typically before the load MCBs, so it can detect the current flowing to the sub-circuits .
5. Neutral wires are connected to the neutral busbar, and all earth connections go to the earth busbar for safety .

Safety Considerations

• Ensure the distribution box is de-energized before installation.
• Verify that the current switch rating matches the expected current range of the monitored conductor.
• Maintain proper clearances and avoid contact with live terminals.
• Follow local electrical codes and standards for wiring and mounting . By following these steps, the current switch can be safely and effectively integrated into a distribution box, providing reliable monitoring of electrical currents for protection, control, or alarm purposes.