What it is and what it fits
The ABB 1SDA068107R1 is a 4-pole distribution circuit breaker from the XT4 series, fitted with a TMA thermal-magnetic trip unit adjustable from 125 A to 1250 A and factory set at In=125 A (100% of In). The frame rating Iu=160 A sets the physical limit for the current path, so the trip adjustment range up to 1250 A only applies if the frame can support it — practically, the adjustable range is limited by the Iu of 160 A, meaning the highest continuous current you can set is the In rating of 125 A, but the breaker can handle short-time overloads up to its breaking capacity. Rated 690 V AC at 50/60 Hz, it is built for main or feeder protection in low-voltage distribution panels. The XT4 frame (8.25 cm wide x 14 cm deep x 16 cm tall) is shared across several current ratings, so panel cutouts and busbar connections are consistent. If you're swapping in a panel originally designed for a higher-rated XT4 breaker like 1SDA068109R1 (200 A), the physical mounting is identical — no rewiring needed for the breaker position, though the protective settings must be verified against the load.
Panel integration notes
Mounts in the XT4 footprint; the cutout measures 8.25 cm × 14 cm × 16 cm. The TMA trip unit is adjustable; verify the dial is set to 125 A.