Allanson 2721-668 Transformer

The Allanson 2721-668 Ignition Transformer is a heavy-duty, iron-core electromagnetic unit designed for reliable oil burner ignition. This transformer operates on a 120Vac supply voltage and delivers a high-voltage 10,000Vac secondary output at 23mA. Engineered with a midpoint ground configuration, it ensures stable arc performance and consistent combustion in residential and commercial heating systems. As the direct replacement for 2721-668SF models, it maintains the precise physical footprint and mounting requirements necessary for a seamless field swap. Technicians prefer the 2721 series for its robust internal insulation and ability to withstand high ambient temperatures without thermal breakdown. When troubleshooting HVAC ignition failure, this 10kV ignition transformer provides the electrical intensity required to bridge gaps in diverse environmental conditions. It is essential for maintaining efficient fuel atomization and reliable cold-start performance in legacy and modern oil-fired equipment.

Technical Specifications and Key Benefits

• Direct Cross-Reference: Replaces Allanson 2721-668SF without kit modifications.
• High Dielectric Strength: 10,000V secondary output for dependable oil burner arc stability.
• Midpoint Ground Design: Optimizes safety and electrical balance during continuous or intermittent duty.
• Input Requirements: Standard 120V, 60Hz primary supply voltage for universal compatibility in North American systems.
• Inductive Response: 23mA secondary current maintains the thermal energy needed for consistent oil igniter performance.

Common Installation Questions

Is the Allanson 2721-668 compatible with older 2721-668SF models?
Yes, the 2721-668 is the verified replacement ignition transformer for the discontinued "SF" suffix version, sharing the same voltage and physical specifications.

Why is lead length important for this transformer?
Standard lead lengths on the 2721 series are designed to reach terminal connections within standard burner housings; always verify your specific enclosure clearance when installing HVAC service parts.

Can I use this transformer with a primary control that supports intermittent ignition?
Yes, this heavy-duty transformer is rated for duty cycles typically found in both intermittent and interrupted ignition sequences used in oil heating systems.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.