The Circutor CMC 12 B (code R281A6) is a capacitor-switching contactor from the CMC-B series, designed to switch single-step and multi-step capacitor banks in reactive power correction installations. It delivers up to 12.5 kvar at 400-480 V (and up to 18 kvar at 660-690 V) with a 230 Vac coil, and is rated for an electrical lifetime of 200,000 switching cycles.

Technical specifications:

• Model: CMC 12 B
• Circutor code: R281A6
• EAN: 8433059202842
• Frequency: 50/60 Hz
• Nominal voltage range: 220 – 690 V
• Operating power at 220-240 V: 6.7 kvar
• Operating power at 400-440-480 V: 12.5 kvar
• Operating power at 500-550 V: 15 kvar
• Operating power at 660-690 V: 18 kvar
• Coil voltage: 230 Vac (tolerance: 0.85 – 1.1 Un)
• Nominal operating current: 18.5 A (at 400 V)
• Switching rate: 240 operations/h
• Electrical lifetime: 200,000 cycles
• Insulation voltage: 690 – 1000 V
• Damping resistors: 1
• Dimensions (W x H x D): 44.8 x 72.2 x 107.9 mm
• Weight: 0.32 kg
• Protection class: IP 00
• Operating temperature: -25 to +55 C
• Relative humidity: 5 – 95% (non-condensing)
• Maximum installation altitude: 2000 m
• Standards: IEC 60947-4-1, VDE 0660

Features and benefits:

• One built-in damping resistor limits inrush current when the capacitor bank is energised, reducing stress on the contactor and connected capacitors
• An electrical lifetime of 200,000 cycles supports continuous, long-term operation in demanding power factor correction duty
• A switching cadence of up to 240 operations per hour accommodates high-frequency step control by automatic power factor regulators
• Wide voltage compatibility from 220 V to 690 V at 50 and 60 Hz suits a broad range of grid configurations and international applications
• Compact footprint of 44.8 x 72.2 x 107.9 mm and a weight of just 0.32 kg simplify integration into space-constrained control panels

Applications:

• Switching single-step capacitor banks in industrial and commercial power factor correction panels
• Switching multi-step capacitor banks under control of an automatic power factor regulator
• Reactive power compensation in 400 V three-phase distribution networks in manufacturing and commercial facilities
• Capacitor bank installations on medium-voltage systems operating at 660-690 V

Also known as: Circutor CMC 12 B, CMC 12 B R281A6, R281A6 capacitor contactor, CMC-B contactor, capacitor switching contactor.