White-Rodgers 90-T40M1 Class 2 Transformer

The White-Rodgers 90-T40M1 Class 2 Transformer delivers dependable low-voltage control power for HVAC systems by stepping down line voltage to power thermostats, relays, gas valves, and other control circuits. It is commonly installed in furnaces, air handlers, control panels, refrigeration systems, and HVAC equipment across residential, commercial, and industrial environments, providing stable Class 2 output that supports reliable thermostat communication and component operation. Engineered for continuous-duty operation, this transformer supports heating, cooling, and process-control applications, making it suitable for both new installations and retrofits where low-voltage power distribution is essential. Mounting options include panel- or equipment-mounted configurations, designed to integrate into existing control architectures and supply low-voltage control power for thermostats, relays, and gas-valve circuits. Common replacements include Honeywell AT140A, Packard PF42440, and Mars 50354 Class 2 transformers.