The Circutor CMC 75 B (code R281A9) is a capacitor-switching contactor from the CMC-B series, purpose-built for energising and de-energising single-step or multi-step capacitor banks in reactive power compensation systems. It carries a nominal operating current of 73 A at 400 V and delivers up to 70 kvar at 660-690 V, covering a wide supply voltage range of 220 to 690 V at 50/60 Hz.

Technical specifications:

• Model: CMC 75 B
• Circutor code: R281A9
• EAN: 8433059202880
• Frequency: 50/60 Hz
• Nominal voltage range: 220 … 690 V AC
• Maximum operating power at 220-240 V: 29 kvar
• Maximum operating power at 400-440-480 V: 50 kvar
• Maximum operating power at 500-550 V: 60 kvar
• Maximum operating power at 660-690 V: 70 kvar
• Nominal operating current: 73 A (at 400 V)
• Coil voltage: 230 V AC, tolerance 0.85 … 1.1 Un
• Dumping resistors: 1
• Cadence of manoeuvre: 100 operations per hour
• Electrical lifetime: 100,000 switching cycles
• Insulation voltage: 690 … 1000 V
• Dimensions (W x H x D): 64.6 x 120 x 150 mm
• Weight: 1 kg
• Protection class: IP 00
• Working temperature: -25 … +55 C
• Relative humidity: 5 … 95% (without condensation)
• Standards: IEC 60947-4-1, VDE 0660

Features and benefits:

• Rated for 100,000 switching cycles, providing long service life in demanding reactive power correction installations.
• Wide nominal voltage range from 220 V to 690 V makes the unit compatible with both low-voltage European and international distribution networks.
• Supports up to 100 switching operations per hour, meeting the high switching frequencies typical of automatic power factor correction systems.
• Includes one integrated dumping resistor to limit transient inrush currents when the capacitor bank is energised.
• Broad operating temperature range from -25 to +55 C allows installation in diverse industrial environments.

Applications:

• Switching single-step capacitor banks in fixed power factor correction panels.
• Controlling individual steps in multi-step automatic power factor correction systems.
• Reactive power compensation in industrial low-voltage distribution switchboards.
• Integration into automatic reactive power regulators managing multi-stage capacitor banks.

Also known as: Circutor CMC 75 B, CMC 75 B R281A9, R281A9 capacitor contactor, capacitor-switching contactor, power factor correction contactor.