Overview

The AVK COSIMAT C2.1 Automatic Voltage Regulator (AVR) represents cutting-edge voltage control technology designed specifically for synchronous alternators in generator applications. This compact, highly reliable AVR provides precise voltage regulation to ensure your generator delivers consistent, stable power output regardless of load variations or operating conditions. The COSIMAT C2.1 is AVK's standard production model, trusted by generator manufacturers, industrial facilities, data centers, hospitals, and commercial operations worldwide to maintain critical power quality and protect sensitive equipment from voltage fluctuations that can cause damage or operational failures.

Engineered with advanced circuitry and robust components, the AVK COSIMAT C2.1 AVR offers two distinct methods of influencing alternator voltage output, including sophisticated under-frequency protection (U/F function) and under-speed protection capabilities. This dual-mode operation ensures your generator automatically adjusts voltage based on frequency variations, preventing over-excitation during startup and protecting the alternator from damage during abnormal operating conditions. Whether you're replacing a failed AVR, upgrading your existing voltage regulation system, or maintaining backup power equipment, the COSIMAT C2.1 delivers the performance, reliability, and precision that AVK is renowned for across the global power generation industry.

Key Specifications

Compatible Alternator Models

The AVK COSIMAT C2.1 AVR is designed as a direct replacement and standard voltage regulator for a wide range of AVK alternator series and generator configurations. This AVR is fully compatible with AVK synchronous alternators including the popular DIG, DIH, DII, DSG, DSI, and other industrial alternator series manufactured by AVK. The COSIMAT C2.1 is also compatible with Newage Stamford alternator models where AVK voltage regulation is specified by the manufacturer. Generator sets powered by engines from Perkins, Cummins, Caterpillar, John Deere, Volvo Penta, Deutz, and other major diesel engine manufacturers frequently utilize AVK alternators with the COSIMAT C2.1 AVR as the standard voltage regulation system. This AVR is suitable for applications ranging from 5kVA to several hundred kVA, depending on the specific alternator configuration and excitation requirements. When ordering, always verify your existing AVR model number and alternator nameplate data to ensure proper compatibility. If you're unsure whether the COSIMAT C2.1 is the correct AVR for your generator, contact our technical support team with your generator's serial number and alternator model information for expert verification and guidance.

Why Buy from General Power

When you purchase your AVK COSIMAT C2.1 Automatic Voltage Regulator from General Power, you're partnering with an authorized distributor of genuine OEM generator parts with over three decades of experience serving the power generation industry. We stock only 100% authentic, factory-new AVK components—never refurbished, never counterfeit—ensuring you receive the exact same quality AVR that was originally installed in your generator at the factory. Our commitment to same-day shipping on in-stock items means your critical replacement part ships fast, minimizing your generator downtime and keeping your backup power systems operational when you need them most.

General Power provides comprehensive bilingual technical support from knowledgeable parts specialists who understand generator systems inside and out. Whether you need help verifying compatibility, interpreting wiring diagrams, troubleshooting voltage regulation issues, or guidance on installation procedures, our team is here to help. We serve customers across North America including the United States, Canada, and Mexico, with reliable shipping options and competitive pricing on all AVK parts and accessories. For immediate assistance, technical questions, or to place your order by phone, call our customer service team toll-free at 1-888-769-3758. We're committed to providing not just quality parts, but the expertise and support that ensures your generator repair or maintenance project succeeds.

Installation Overview

Installing the AVK COSIMAT C2.1 AVR requires basic electrical knowledge and adherence to safety protocols. Always follow these essential steps:

• Step 1: Power Isolation and Safety – Before beginning any work, completely shut down the generator and disconnect all power sources including battery connections. Lock out and tag out the generator control panel to prevent accidental startup during AVR replacement. Allow the generator to cool completely and discharge any residual voltage from capacitors. Wear appropriate personal protective equipment including insulated gloves and safety glasses.
• Step 2: Remove Failed AVR – Document the existing wiring configuration by photographing wire connections or creating a detailed wiring diagram before disconnecting anything. Label each wire with tape or tags corresponding to the terminal positions. Carefully disconnect all wiring harnesses from the old AVR, noting the wire colors and terminal positions (typically including sensing voltage inputs, excitation output to the alternator field, power supply, and any auxiliary connections). Remove the mounting screws and extract the failed COSIMAT C2.1 from the panel.
• Step 3: Install New AVR – Position the new AVK COSIMAT C2.1 AVR in the mounting location and secure it with the appropriate mounting hardware, ensuring the unit is firmly attached and properly grounded. Reconnect all wiring exactly as documented, ensuring each wire is connected to the correct terminal with secure, tight connections. Double-check that sensing voltage inputs, excitation outputs, and ground connections are all properly made. Verify that no wire strands are exposed that could cause short circuits.
• Step 4: Testing and Adjustment – After all connections are verified, restore power to the generator control panel and start the generator without load. Monitor the output voltage using a calibrated multimeter and observe AVR operation. The generator should build voltage smoothly to the nominal setpoint (typically 120V/240V or 230V/400V depending on configuration). If voltage adjustment is required, follow the manufacturer's instructions for trimming voltage using the adjustment potentiometer on the AVR. Apply test loads progressively while monitoring voltage regulation performance to confirm proper operation under varying load conditions. If the generator fails to build voltage or regulation is erratic, immediately shut down and recheck all wiring connections.

Important Note: AVR installation should be performed by qualified electrical technicians familiar with generator systems. Incorrect installation can damage the AVR, alternator, or connected equipment. If you're not experienced with generator electrical systems, contact a certified generator service technician. General Power's technical support team is available to answer installation questions at 1-888-769-3758.

Frequently Asked Questions

Q: What does the AVK COSIMAT C2.1 AVR do in my generator?
A: The COSIMAT C2.1 Automatic Voltage Regulator controls the excitation current supplied to your alternator's rotor field winding, automatically adjusting it to maintain stable output voltage regardless of load changes. When electrical loads are applied to your generator, the AVR senses the voltage drop and increases excitation current to compensate, keeping voltage within tight regulation limits (typically ±1%). It also provides under-frequency protection to prevent over-excitation when the engine is operating below rated speed, protecting both the alternator and connected equipment from damage.

Q: How do I know if my COSIMAT C2.1 AVR is failing or needs replacement?
A: Common symptoms of AVR failure include: unstable generator voltage that fluctuates significantly under load, complete failure to build voltage when the generator starts, over-voltage conditions that trip protective devices or damage equipment, under-voltage that prevents proper operation of connected loads, or erratic voltage swings without corresponding load changes. You may also notice physical damage to the AVR such as burnt components, discolored circuit boards, or melted connectors. If your generator exhibits any of these symptoms, the AVR should be tested or replaced. Always rule out other causes such as wiring issues, failed sensing circuits, or alternator problems before replacing the AVR.

Q: Is this an authentic OEM AVK part or an aftermarket replacement?
A: General Power supplies only 100% genuine, factory-new OEM parts manufactured by AVK (Newage Stamford). The COSIMAT C2.1 AVR you receive is the exact same voltage regulator that AVK installs in their alternators during original manufacturing. We do not sell aftermarket, refurbished, or counterfeit components. Each AVR comes in original AVK packaging with manufacturer documentation and carries the full factory warranty. Authentic OEM parts ensure proper fit, reliable performance, and compatibility with your AVK alternator's specifications.

Q: What warranty coverage is included with the AVK COSIMAT C2.1 AVR?
A: The AVK COSIMAT C2.1 AVR is covered by AVK's standard manufacturer warranty against defects in materials and workmanship. Warranty terms typically cover a period of 12-24 months from date of purchase when installed and operated according to manufacturer specifications. The warranty covers replacement or repair of defective units but does not cover damage caused by improper installation, incorrect voltage or frequency application, environmental damage, or normal wear and tear. For specific warranty terms and to register your product, contact General Power at the time of purchase. We will assist with any warranty claims and coordinate directly with AVK if warranty service is required.

Q: Can I get technical support for installation and troubleshooting?
A: Absolutely! General Power provides comprehensive technical support for all products we sell, including the AVK COSIMAT C2.1 AVR. Our bilingual support team includes experienced generator technicians who can help with compatibility verification, wiring diagrams, installation guidance, voltage adjustment procedures, and troubleshooting assistance. Technical support is available by phone at 1-888-769-3758 during business hours, and we can also provide support via email for non-urgent technical questions. We maintain extensive technical documentation, wiring diagrams, and service manuals for AVK products to ensure you have the resources needed for successful installation and operation.

Order Today

Don't let a failed voltage regulator keep your critical backup power system offline. Order your genuine AVK COSIMAT C2.1 Automatic Voltage Regulator from General Power today and get your generator back to reliable operation quickly. With our same-day shipping on in-stock items, competitive pricing, and expert technical support, we make generator repair and maintenance easy and hassle-free. Every COSIMAT C2.1 AVR we ship is factory-new, OEM quality, and backed by manufacturer warranty for your complete peace of mind. Whether you're a facility maintenance professional, generator service technician, or equipment owner, General Power is your trusted source for authentic AVK parts and the expertise to keep your power generation equipment running at peak performance. Call 1-888-769-3758 now to speak with a parts specialist, verify compatibility for your specific alternator model, or place your order. You can also order securely online 24/7 through our website. Get the genuine OEM quality your generator deserves—order your AVK COSIMAT C2.1 AVR from General Power today and experience the difference that authorized distribution, technical expertise, and exceptional customer service make!