In Star-Delta starter with type 1 & type 2 coordination, which is the mounting position of OLR? Should it be after the line contactor (OR) Before Line+Star/Delta connection?

Star-Delta Type 2 coordination: The thermal overload relay should be placed in the Main power supply line before the splitting for star-delta connection.

Star-Delta Type 1 coordination: The thermal overload relay is placed in the Delta circuit.

For the Type 2 coordination the thermal overload relay selection is based on the Full load current rating and selection for type 1 coordination is based on Full load current / Sqrt 3 (FLC/1.732).

The schemes published on the Catalog for Star-delta are for the Type 1 coordination only and there is no scheme available for Type 2 coordination in the catalog.

Please find in attachment scheme for the mounting position of OLR for Type 1 & 2 coordination with Star-delta starter.

Released for:Schneider Electric Nigeria