S291-Cxxx Datasheet | ABB

Pro M Miniature circuit breakers General information General information Miniature circuit breakers (MCBs) are used throughout the world in all types of electrical installations. ABB MCBs are recognized for use by Underwriters Laboratories Standard UL1077 for supplementary circuit protectors in .. systems rated 240VAC, 480VAC and 600VAC. Devices are certified per CSA C22.2. MCBs are approved per IEC-898 and VDE 0641, and certified under IEC-947 and VDE 0660 standards for use in systems rated 415VAC or 690VAC (S500 series). MCBs can be applied to 16 2/3Hz - 400Hz and DC power systems. Special direct current version MCBs include a permanent magnet for DC fault current interruption. These "UC" versions are rated 250/500VDC under UL1077/CSA 22.2 No. 235. Continuous current ratings are as low as 0.2 amperes and up to 125 amperes maximum. MCBs are of pact size and can be quickly mounted on standard 35mm DIN rail or can be front mounted by use of a front mounting kit. MCBs include line and load side terminals for conductors from 18 through 4AWG (0.75 - 25mm2) for 40 amperes; up to 2AWG for 50 and 63 amperes. MCBs can also be connected via busbar conductors which can be either upper or lower mounted for top feed or bottom feed. Dual function terminals allow busbars to be connected with main ining line conductors without separate lugs. CSA C22.2 MCBs and accessories are certified under CSA C22.2 No. 235 per File LR98793. Tripping characteristics Time-current curves ABB miniature circuit breakers are available with different trip characteristics, allowing for maximum system protection. B Characteristic Available with the S260 series has rated currents of 6 through 63 amperes in 10 steps. The "B" timecurrent curve is designed primarily for use in cable protection applications. Instantaneous tripping occurs between approximately 3 to 5 times rated current in 50/ 60Hz systems. This quick trip curve maximizes protection of control circuits under low short circuit fault levels...