The CA4-01 is an auxiliary contact block designed as an accessory for ABB block contactors, providing one normally closed (NC) contact for auxiliary circuit control. It is rated for auxiliary circuit voltages from 24 to 690 V AC/DC with a rated frequency of 50/60 Hz and a rated insulation voltage of 600 V (UL/CSA) or 690 V (IEC 60947-5-1). The contact carries a rated operational current of 4 A at 220/240 V AC-15, 6 A at 24/127 V AC-15, 3 A at 400/440 V AC-15, and 2 A at 500–690 V AC-15, with a maximum electrical switching frequency of 1200 cycles per hour (AC-15) or 900 cycles per hour (DC-13) and a mechanical switching frequency of 3600 cycles per hour. The block features screw terminals with a tightening torque of 1.2 N·m, accepts flexible or rigid conductors from 0.75 to 2.5 mm², and is compatible with ABB contactors AF09 through AF96 and NF series. It is suitable for auxiliary control circuits in industrial automation, motor control, and power distribution applications.