The Trane TRR1998 Transformer is an electrical component designed to supply low-voltage power to HVAC control systems. It works by converting high-voltage input into a stable lower voltage through electromagnetic induction, ensuring safe operation of control circuits. Commonly used in air handlers, furnaces, and rooftop units, it powers thermostats, relays, and other controls. Its use enhances system reliability, improves electrical safety, and supports consistent performance, making it essential for efficient and dependable HVAC operation.