Y66F12-0 Johnson Controls Transformer

Overview

The Johnson Controls Y66F12-0 is a robust, step-down control transformer engineered for demanding commercial and industrial HVACR and building automation applications. It is designed to safely convert high-voltage primary power into a stable 24V secondary output, delivering reliable power to low-voltage control strings, digital controllers, and inductive loads. It features built-in thermal protection and an integrated circuit breaker to simplify installation and protect components from electrical overloads.

Features

• Dual Primary Input: Supports both 277VAC and 480VAC configurations, offering excellent field installation flexibility.
• Stable 24VAC Output: Supplies standard low-voltage power for commercial thermostats, actuators, relays, and control boards.
• Integrated Circuit Breaker: Provides built-in overcurrent protection with an easy reset, eliminating the need for a separate fuse.
• Simplified Wiring: Equipped with a common male fitting and pre-attached 8-inch color-coded primary and secondary leads.
• Split-Bobbin Design: Delivers high primary-to-secondary electrical isolation for enhanced safety and performance.
• Rugged Construction: Built with a heavy-duty metal frame and corrosion-resistant finish for secure, vibration-resistant foot-mounting.

Specifications

• Manufacturer: Johnson Controls
• Model Part Number: Y66F12-0
• Product Series: Y66 Series
• Type: Control Power Transformer (Class 2)
• Power Capacity: 75 VA
• Input Primary Voltage: 277 VAC / 480 VAC at 60 Hz
• Output Secondary Voltage: 24 VAC nominal (23.5 VAC full load, 27.0 VAC open circuit)
• Phase: 1 (Single Phase)
• Overcurrent Protection: Integrated Circuit Breaker
• Connections: Common male fitting with 8-inch wire leads
• Mounting: Foot Mount
• Operating Temperature: -40 to 104°F (-40 to 40°C)
• Agency Compliance: UL Listed/Recognized (File E95575), cURus Class 2 certified

Applications

• Commercial HVAC control and climate systems
• Building automation systems (BAS) and energy management applications
• Packaged rooftop units, large air handling units (AHUs), and VAV systems
• Industrial control panels requiring reliable 24V control power
• Power supply setups for motor actuators, digital controllers, gas valves, contactors, and ignition systems