The Circutor CMC 40 B (code R281A1) is a capacitor-switching contactor from the CMC-B series, built for commutating single-step and multi-step capacitor banks in reactive power compensation systems. It handles up to 40 kvar at 660-690 V across an operating voltage range of 220 to 690 V AC, with a 230 Vac control coil and a rated current of 44 A at 400 V.Technical specifications: Model: CMC 40 B Circutor code: R281A1 EAN: 8433059202873 AC supply voltage: 220 ... 690 V Frequency: 50/60 Hz Coil voltage: 230 Vac (tolerance: 0.85 ... 1.1 Un) Nominal operating current: 44 A (at 400 V) Switching capacity at 220-240 V: 20 kvar Switching capacity at 400-440-480 V: 30 kvar Switching capacity at 500-550 V: 35 kvar Switching capacity at 660-690 V: 40 kvar Damping resistors: 1 Cadence of operation: 100 operations/h Electrical lifetime: 200,000 cycles Insulation voltage: 690 ... 1000 V Dimensions (W x H x D): 54.8 x 80 x 124.5 mm Weight: 0.6 kg Protection class: IP 00 Operating temperature: -25 ... +55 °C Relative humidity: 5 ... 95% (non-condensing) Standards: IEC 60947-4-1, VDE 0660 Features and benefits: One integrated damping resistor limits inrush current when the capacitor bank energizes, reducing electrical stress on the switching circuit. Electrical lifetime of 200,000 cycles supports sustained high-frequency switching duty without premature wear. Cadence rating of 100 operations per hour enables rapid response in automatic power factor correction systems. Wide operating voltage range of 220 to 690 V makes this contactor compatible with a broad range of low-voltage distribution networks. Operating temperature range of -25 to +55 °C supports installation in both indoor and demanding industrial environments. Applications: Switching single-step capacitor banks in reactive power compensation installations Stepping through stages in multi-step automatic power factor correction panels Industrial switchgear assemblies requiring controlled capacitor bank switching at voltages up to 690 V Commercial and industrial sites where frequent capacitor bank commutation is needed Also known as: Circutor CMC 40 B, CMC 40 B R281A1, capacitor bank contactor, capacitor switching contactor, R281A1 contactor.
