Description

277V Output Auto-Transformer for LED Drivers Ballasts

480V / 347V Input

Open Core Design

The Keystone KTAT-150-480-277-OC is a compact step down auto-transformer designed to convert 480V or 347V input power to a stable 277V output for LED drivers and lighting ballasts. Built with an open core metal housing, this non-isolated auto-transformer is ideal for commercial and industrial lighting systems where 277V operation is required from higher-voltage electrical services.

With a maximum capacity of 150VA and high operating efficiency, this Keystone auto-transformer supports reliable performance in new installations and retrofit applications. It is UL listed and engineered for long-term operation in demanding electrical environments.

Specifications

• Model: KTAT-150-480-277-OC
• Type: Step Down Auto-Transformer (Non-Isolated)
• Input Voltage: 480V / 347V AC ±10%
• Output Voltage: 277V AC
• Maximum Power: 150VA
• Frequency: 50/60 Hz
• Efficiency: 95% typical
• No Load Power Consumption: < 8W
• Sound Rating: A
• Withstand Voltage: Input to Output, 2000Vac
• Maximum Case Temperature: 105°C (221°F)
• Certifications: UL / cUL 5085
• Warranty: 5 Years

Physical Details

• Length: 2.76 inches
• Width: 2.32 inches
• Height: 1.93 inches
• Mounting Length: 2.17 inches
• Unit Weight: 1.95 lbs
• Case Material: Metal

Wiring

• Input Leads: 14 inches, UL 1316, 18 AWG (red, yellow, white)
• Output Leads: 14 inches, UL 1316, 18 AWG (black, blue, white)
• Compatible with 3-phase Wye or Delta power systems (see wiring diagram)