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.