Overview

The LEROY SOMER R220 AVR (Automatic Voltage Regulator) is a precision-engineered voltage regulation solution designed primarily for single-phase generator applications, though it can also be effectively installed in three-phase 12-wire generator configurations. This OEM replacement AVR ensures stable, consistent voltage output for your generator system, protecting sensitive electrical equipment from damaging voltage fluctuations and surges. The R220 utilizes shunt excitation technology and is specifically designed for compatibility with Leroy Somer's LSA40 and LSA42.3 alternator series, delivering reliable performance in industrial, commercial, and standby power applications. Whether you're maintaining critical backup power systems, operating construction equipment, or managing industrial generators, the R220 provides the voltage stability essential for safe, efficient operation.

As a genuine Leroy Somer component, the R220 AVR represents decades of engineering excellence in generator voltage regulation technology. This automatic voltage regulator continuously monitors your generator's output voltage and makes real-time adjustments to maintain consistent power delivery regardless of load variations or engine speed fluctuations. The compact, robust design ensures long-term reliability even in challenging environmental conditions, while the shunt excitation configuration simplifies installation and maintenance procedures. For applications requiring AREP (Auxiliary winding with Rotating Exciter and Permanent magnet) or PMG (Permanent Magnet Generator) excitation systems, Leroy Somer offers alternative models such as the R450 and D510C, but for straightforward shunt-excited single-phase and select three-phase installations, the R220 remains the optimal choice for generator operators seeking dependable voltage regulation at an excellent value.

Key Specifications

Compatible Alternator Models

The Leroy Somer R220 AVR has been specifically engineered for seamless integration with Leroy Somer's LSA40 and LSA42.3 alternator series, which are among the most widely deployed industrial alternators globally. These alternator models are commonly found in generator sets ranging from small commercial backup systems to mid-sized industrial applications. The LSA40 series alternators typically range from 10 kVA to 40 kVA output, while the LSA42.3 series covers similar power ranges with enhanced performance characteristics. Both alternator families utilize shunt excitation systems, making the R220 the ideal voltage regulation solution. Generator set manufacturers who commonly incorporate these Leroy Somer alternators include major OEMs in the power generation industry, and the R220 AVR serves as the factory-standard voltage regulator for these configurations. When replacing an existing R220, it's essential to verify your alternator model designation, typically found on the alternator nameplate, to ensure compatibility. The R220 is designed exclusively for shunt-excited systems; if your generator employs AREP excitation or PMG (Permanent Magnet Generator) technology, you will require alternative Leroy Somer AVR models such as the R450 for AREP applications or the D510C for PMG systems. Always consult your generator's technical documentation or contact General Power's technical support team to confirm the correct AVR model for your specific alternator configuration.

Why Buy from General Power

General Power is your authorized dealer for genuine OEM Leroy Somer parts, including the R220 AVR. When you purchase from General Power, you receive factory-authentic components backed by manufacturer warranties and our commitment to customer satisfaction. We maintain extensive inventory of critical generator components, enabling same-day shipping on most orders placed before our cut-off time, minimizing your equipment downtime and getting your generator back to operational status quickly. Our team of technical specialists provides comprehensive support throughout your purchase and installation process, and we're proud to offer bilingual customer service to better serve our diverse customer base across North America. Whether you need assistance identifying the correct AVR for your alternator model, troubleshooting installation challenges, or understanding compatibility requirements, our knowledgeable staff is ready to help. Contact General Power today at 1-888-769-3758 to speak with a generator parts specialist who can answer your questions, verify compatibility, and process your order efficiently. We understand that generator downtime means lost productivity and revenue, which is why we've built our business around rapid response, genuine OEM quality, and expert technical support that keeps your power systems running reliably.

Installation Overview

Installing the Leroy Somer R220 AVR requires basic electrical knowledge and adherence to safety protocols. Here's a general overview of the installation process:

• Step 1: Safety Preparation and Removal – Begin by completely shutting down the generator and disconnecting all power sources. Allow adequate time for capacitors to discharge. Locate the existing AVR, typically mounted on or near the alternator assembly. Carefully photograph or document all wire connections before removal, noting wire colors and terminal positions. Remove the mounting screws or fasteners securing the old AVR and carefully disconnect all wiring harnesses, taking care not to damage connector pins or terminals.
• Step 2: Inspection and Preparation – Before installing the new R220 AVR, inspect all wiring connections for signs of damage, corrosion, or overheating. Clean terminal connections if necessary and verify that all connectors are in good condition. Compare the new R220 with the removed unit to confirm matching terminal configurations. Check that the mounting location provides adequate ventilation and protection from environmental contamination while remaining accessible for future maintenance.
• Step 3: Installation and Connection – Mount the new R220 AVR in the designated location using appropriate hardware, ensuring secure attachment that will withstand generator vibration. Connect all wiring according to the manufacturer's wiring diagram and your documentation from the removal process. Typical connections include sensing inputs, excitation outputs, and any auxiliary control wiring. Verify that all connections are tight and properly seated, with no loose strands that could cause short circuits.
• Step 4: Testing and Calibration – Once all connections are secure, perform a thorough visual inspection before restoring power. Start the generator and allow it to reach operating temperature while monitoring voltage output with a reliable multimeter. Check that voltage remains stable across varying load conditions. If adjustment is necessary, follow the manufacturer's calibration procedures, typically involving potentiometer adjustments to achieve the desired voltage setpoint. Verify proper voltage regulation under no-load, partial-load, and full-load conditions before returning the generator to service.

Important: AVR installation should be performed by qualified technicians familiar with generator systems and electrical safety procedures. Always consult the official Leroy Somer installation documentation and follow all applicable electrical codes and safety standards. If you're uncertain about any aspect of the installation process, contact General Power's technical support team at 1-888-769-3758 for guidance.

Frequently Asked Questions

Q: What does the R220 AVR do for my generator?
A: The R220 Automatic Voltage Regulator continuously monitors your generator's electrical output and automatically adjusts the excitation current to the alternator's rotor winding, maintaining stable voltage output regardless of load changes or engine speed variations. This protects connected equipment from damage caused by voltage fluctuations and ensures consistent power quality for sensitive electronics, motors, and other electrical loads.

Q: How do I know if my AVR is failing and needs replacement?
A: Common symptoms of AVR failure include unstable voltage output that fluctuates significantly with load changes, consistently high or low voltage readings that cannot be corrected through adjustment, complete loss of voltage output despite the engine running properly, or visible damage such as burnt components, discolored circuit boards, or melted connectors. If you experience any of these symptoms, the AVR should be tested and likely replaced. Our technical team can help you diagnose AVR-related issues by phone.

Q: Is this a genuine OEM Leroy Somer part or an aftermarket replacement?
A: General Power supplies only genuine OEM Leroy Somer R220 AVRs – factory-original parts manufactured by Leroy Somer to exact specifications. We do not sell aftermarket or third-party imitations. When you purchase the R220 from General Power, you receive an authentic Leroy Somer component with full manufacturer backing, ensuring proper fit, reliable performance, and compatibility with your alternator system.

Q: What warranty coverage is included with the R220 AVR?
A: The Leroy Somer R220 AVR is covered by the manufacturer's standard warranty against defects in materials and workmanship. Warranty terms typically include coverage for a specified period from the date of purchase when the AVR is installed and operated according to manufacturer specifications. General Power stands behind every product we sell and will assist with any warranty claims or issues that arise. Contact our customer service team for specific warranty details and coverage information for your purchase.

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 R220 AVR. Our knowledgeable staff can assist with compatibility verification, installation guidance, wiring questions, calibration procedures, and troubleshooting support. We offer bilingual customer service and can provide technical assistance in English or Spanish. Call us at 1-888-769-3758 to speak with a generator parts specialist who can help ensure successful installation and operation of your R220 AVR.

Order Today

Don't let a failed voltage regulator keep your generator offline and compromise your power security. The Leroy Somer R220 AVR is in stock at General Power and ready for immediate shipment to your location. As an authorized Leroy Somer dealer, we guarantee you'll receive a genuine OEM component that meets exact factory specifications for your LSA40 or LSA42.3 alternator. Our same-day shipping service ensures minimal downtime for your critical power equipment, and our competitive pricing delivers exceptional value without compromising on quality or authenticity. Whether you're a facility maintenance professional, generator service technician, or equipment owner managing your own power systems, General Power provides the expertise, inventory, and support you need to maintain reliable generator operation. Our bilingual customer service team is standing by to answer your questions, verify compatibility with your specific alternator model, and process your order quickly and accurately. Call 1-888-769-3758 now to speak with a generator parts specialist, or place your order through our secure online system for fast delivery of your genuine Leroy Somer R220 Automatic Voltage Regulator. Trust General Power for authentic OEM generator parts, expert technical support, and the rapid service that keeps your power systems running when you need them most.