Lennox 10P87 – Honeywell AT87A1106/U, Class 2 Transformer, 48 VA, 120/208/240 VAC Primary, 24 VAC Secondary

 

Lennox 10P87 – Honeywell AT87A1106/U Class 2 Transformer is a high-reliability 48 VA control transformer designed to provide stable, low-voltage 24 VAC power for a wide range of HVAC systems. Engineered for long-term performance, this transformer supports multi-voltage primary inputs (120/208/240 VAC at 50/60 Hz), making it a versatile replacement part for residential and light commercial heating and cooling equipment. Its compact, durable construction ensures consistent operation in demanding environments where dependable low-voltage control power is required.

This Honeywell AT87A1106/U transformer is commonly used in furnaces, air handlers, and other Lennox HVAC units where a Class 2 24-volt power supply is needed for thermostats, relays, ignition controls, zone valves, and safety circuits. The multi-tap design reduces inventory complexity, allowing technicians to replace several transformer models with a single, universal-fit solution. Trusted for its quality and stable output, it helps restore reliable system performance and protect downstream components.

 

Technical specifications

• Model: Honeywell AT87A1106/U
• Lennox Part Number: 10P87
• Transformer Type: Class 2
• VA Rating: 48 VA
• Primary Voltage: 120/208/240 VAC, 50/60 Hz
• Secondary Voltage: 24 VAC
• Application: HVAC control circuits, thermostats, zone valves, ignition modules, relays
• Mounting Style: Foot-mounted
• Construction: Durable laminated core
• Compatibility: Suitable replacement for many Lennox heating and cooling systems requiring 24-volt control power