Allanson Transformers 421-BT387 Transformer

The Allanson 421-BT387 is a heavy-duty ferromagnetic ignition transformer designed for constant-duty service in high-demand oil heating systems. As a universal service replacement, this 120V oil burner transformer delivers a consistent 10,000V secondary output at 23mA, ensuring a stable arc for reliable ignition in residential and commercial applications. Engineered with a mid-point ground and a double-pole configuration, the 421-BT387 features a thumb screw HV terminal and an internal junction box for secure, streamlined field wiring. The Large Can series housing is constructed to run cooler and quieter than standard units, meeting both American and European EMI/RFI emission standards to minimize electrical interference. For technicians performing oil burner transformer troubleshooting, this Allanson 10,000V transformer serves as a robust replacement for a wide range of burner manufacturers, providing the arc intensity required to handle cold starts and varying fuel viscosities.

Key Benefits for Technicians:

• Universal Compatibility: Designed as a versatile service replacement ignition transformer for multiple oil burner brands.
• High-Temperature Rating: Utilizes high-grade internal wiring to maintain performance during continuous-duty operation.
• Simplified Installation: Features an integrated internal junction box and thumb screw terminals to reduce time on the job site.
• Noise Suppression: Advanced design drastically reduces electromagnetic interference (EMI) and radio frequency interference (RFI).
• Consistent Spark: Provides a dependable 10,000V secondary voltage to ensure clean combustion and prevent delayed ignition.

Frequently Asked Questions:

What are the primary 421-BT387 transformer specifications?
This unit operates on a 120VAC 60Hz input, producing a 10,000VAC 23mA secondary output. It is a double-pole, mid-point ground transformer with a thumb screw terminal type.

Can this replace an electronic ignitor?
While often used as a replacement in systems designed for ferromagnetic units, always verify the mounting footprint and "Large Can" dimensions to ensure a proper fit on the burner housing.

Is the Allanson 421-BT387 rated for constant duty?
Yes, this ferromagnetic model is designed for constant-duty ignition, making it suitable for applications where the transformer remains energized throughout the burner cycle.

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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.