Lennox 12P61 – Honeywell AT175A1008/U, Class 2 Transformer, 75 VA, 120/208/240 VAC Primary, 24 VAC Secondary

 

Lennox 12P61 – Honeywell AT175A1008/U Class 2 Transformer is a high-performance 75 VA step-down transformer designed for reliable low-voltage power in HVAC control systems. Engineered for compatibility with furnaces, air handlers, boilers, and zone control applications, this transformer provides a stable 24 VAC output and supports multiple primary voltage inputs, including 120, 208, and 240 VAC at 60 Hz. Its durable construction and consistent output make it ideal for residential and light commercial systems.

This Honeywell AT175A1008/U transformer is widely used in Lennox systems and other major HVAC brands, ensuring easy replacement and long service life. It is suitable for powering thermostats, relays, humidifiers, actuators, safety circuits, and other 24-volt accessories commonly found in modern HVAC installations.

 

Specifications

• Part Number: 12P61
• Manufacturer: Honeywell / Lennox compatible
• Model: AT175A1008/U
• Transformer Class: Class 2
• Power Rating: 75 VA
• Primary Voltage: 120 / 208 / 240 VAC (selectable)
• Primary Frequency: 60 Hz
• Secondary Voltage: 24 VAC
• Secondary Current Capacity: Up to 3.125 A (75 VA / 24 V ≈ 3.125 A)
• Output Type: Low-voltage control power for HVAC accessories
• Mounting Style: Standard HVAC control panel mount (screw terminals)
• Typical Applications: Furnaces, air handlers, boilers, zone control systems, thermostats, relays, humidifiers, safety controls, dampers, actuators
• Compatibility: Direct replacement for Lennox 12P61, suitable for most HVAC systems requiring a 24 VAC, 75 VA Class 2 transformer