Product Overview

Philips MasterColor 400W Ceramic Metal Halide Lamp – M172/M155/O, EX39 ED28, Pulse Start, 4200K

The Philips MasterColor 400 Watt ED28 Ceramic Metal Halide Lamp with an EX39 mogul base is a high-efficiency, pulse start solution for commercial and industrial lighting applications. This protected metal halide lamp is rated for enclosed fixtures and offers excellent color rendering, improved lumen maintenance, and environmental benefits through its ALTO low-mercury design.

Technical Specifications

Wattage: 400 Watts
Base Type: EX39 (Exclusionary Mogul)
Bulb Shape: ED28
Color Temperature: 4200K (Cool White)
Color Rendering Index (CRI): 90
ANSI Code: M172/M155/O
Fixture Requirement: Rated for enclosed or outdoor luminaires
Burn Position: Vertical ±15°
Maximum Overall Length (MOL): 8.13 in
Diameter: 3.5 in
Rated Average Life: 20,000 hours
Case Quantity: Sold in cases of 12 lamps

Key Features

Reduced mercury content vs. standard quartz metal halide for environmental compliance
Patented coil design supports open fixture rating protection
Improved lumen maintenance and lifetime color stability within ±200K
Higher energy efficiency than mercury vapor or traditional metal halide lamps
Operates on standard pulse start metal halide ballasts
Extended life reduces maintenance frequency and relamping costs
End-of-life features via Philips ALTO technology to support easier disposal compliance

Applications

High-ceiling retail stores
Warehouses and distribution centers
Industrial manufacturing facilities
Commercial outdoor area lighting (in enclosed fixtures)

UV Safety Warning

WARNING: This lamp emits ultraviolet radiation which can cause serious skin burns and eye inflammation if the outer envelope is broken or punctured. Do not use where people will remain for prolonged periods unless adequate shielding is used. Lamps that automatically extinguish upon envelope breakage are available. This lamp complies with FDA radiation performance standards: