How do I correctly wire current transformers (CTs) to a Schneider Electric SC150 Switch Control Unit?

[HavenAnn]

Connecting current transformers (CTs) to your Schneider Electric SC150 Switch Control Unit requires careful attention to detail. Here's a step-by-step guide to ensure a safe and correct installation:

1. Wiring Orientation: When attaching the CTs to the cables, make sure the HAUT/TOP marking faces upwards and the wire exit points downwards. This alignment is critical for correct operation.
2. Shielding Re-insertion: Before connecting the CTs to ground, re-insert the shielding of each MV cable back inside its corresponding CT. This is vital for safety.
3. Grounding Connection: The blue wire on the CT secondary (S2) is pre-connected to a blue wire with a round terminal internally. Connect this blue wire with the round terminal to the same frame ground as the cubicle. This ensures proper grounding.
4. Safety First: Always use grounded external CTs for the current inputs to prevent electrical hazards. Before working on or installing CTs on the MV cable, always de-energize the MV network.
5. Current Sensor Specifications: Ensure that you use current sensors with a 1 A or 5 A secondary and a safety factor limiting the current to 100 A secondary - 1 s. Always adhere to the specified standards for current sensors.
6. Tools and Techniques: Use the appropriate tools, such as a suitable screwdriver and crimped end-pieces, for cabling on the connectors. Strip the wires correctly before connecting them to the connectors, following the recommendations in the Schneider Electric SC150 Switch Control Unit's installation guide.

Following these steps, as detailed in the Schneider Electric SC150 Switch Control Unit installation guide, helps ensure that your CTs are connected safely and effectively.