ABB 1SCA153460R1001 OXB250E3X2QT 250A 3P Level 2 DIP Automatic Transfer Switch

The 1SCA153460R1001 order code identifies an ABB TruONE automatic transfer switch, catalog designation OXB250E3X2QT, built for 250 A three-pole switching between two AC sources rated 200 to 480 V. Transfer logic runs on a Level 2 DIP-switch controller with a delayed I-O-II sequence, and the top-supply / bottom-load terminals suit switchboards fed from an overhead riser.

Certifications & Standards

• IEC 60947-6-1

Selection Notes

This 3-pole, 250 A unit skips the switched neutral found on the S-series 4P frames, which fits installations where the neutral conductor is shared and solidly bonded between the two sources rather than switched. A DIP-switch controller sets the transfer parameters locally without a display, the simplest of the three controller options on this frame. Short-time withstand stays at 18 kA for 0.3 s, matching the Level 3 LCD and Level 4 Touch versions on the same 250 A chassis, so controller choice does not change the fault-current basis. The QT terminal layout feeds supply from the top and load from the bottom, the reverse of the QB unit, for installations where cabling drops in from above.