Lennox 10H21 Transformer

The Lennox 10H21 Transformer (Model LB-95312G) is a heavy-duty, factory-authorized step-down transformer engineered specifically for high-voltage industrial and commercial HVAC applications. Featuring a 575V primary input (rated up to 600VAC at 60Hz) and a 230V secondary output, this 175VA transformer provides the high-capacity power regulation required for sophisticated control circuits, contactors, and relays within Lennox equipment.

Built for veteran technicians who demand genuine OEM Lennox parts, the 10H21 ensures exact electrical matching and physical mounting compatibility with select commercial units like the KGA156H4 and LGH242H4 series. Its foot-mount design and lead-wire connections streamline the replacement of aging or failed inductive components, restoring stable voltage levels to prevent flickering control boards or chatter in heavy-load contactors. The dense copper windings and high-grade core materials are designed to withstand the thermal stress and electrical noise common in 575V HVAC systems, maintaining precise 230V output under varying load conditions.

• Precise Voltage Conversion: Converts 575V primary to 230V secondary to safely power auxiliary controls and commercial HVAC components.
• High Power Rating: The 175VA capacity handles significant inrush currents, making it ideal for units with multiple high-draw relays or control accessories.
• OEM Engineering: A direct Lennox 10H21 replacement ensuring the footprint and wiring match factory specifications for zero-modification installs.
• Industrial Durability: Heat-resistant insulation and a robust core design provide long-term stability in demanding rooftop and mechanical room environments.

Is the 10H21 compatible with 600V systems?
Yes, while nominal ratings often state 575V, this transformer is rated for 600VAC primary input at 60Hz, making it standard for Canadian and high-voltage US industrial grids.

Does this include internal circuit protection?
This specific model is a non-protected transformer type. Technicians should ensure the primary and secondary circuits remain protected by the system's existing fuses or breakers.

Can this be used for 24V control circuits?
No, the Lennox 10H21 is a 230V secondary transformer. It is designed to provide high-voltage control power, not for direct connection to standard 24V thermostats or low-voltage logic boards.

Safety Info:
California Proposition 65 Warning – This product may contain materials known to the State of California to cause cancer or reproductive harm.

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.