PHILIPS 400W Pulse Start Metal Halide | 4000K Cool White | E39 Mogul Base | MS400/BU/ED28/PS

Philips MS400BUED28PS (Order Code: 23259-5) is a high-performance pulse start metal halide lamp engineered for superior efficiency and longevity in industrial environments. Delivering a crisp 4000K cool white light, this 400W lamp utilizes pulse start technology to achieve 50% faster warm-up and restrike times than standard HID lamps. With a 20,000-hour rated life and a high luminous efficacy of 120 LPW, it provides a powerful, energy-saving solution for high-bay warehouses, parking structures, and large-scale commercial facilities.

Product Overview

The Philips Pulse Start series is designed to replace aging switch-start technology with a system that offers 25% energy savings and 50% longer lamp life. By using an ignitor to start the lamp rather than a probe, this technology significantly improves lumen maintenance, ensuring the facility stays brighter for longer. The 4000K color temperature delivers a neutral, daylight-like quality that enhances visibility and safety in active work zones. The ED28 bulb shape is more compact than standard ED37 lamps, allowing for more efficient fixture designs without sacrificing intensity.

• Pulse Start Efficacy: Features 120 LPW, providing 25% higher maintained lumens over the life of the lamp compared to traditional metal halide.
• Rapid Restoration: Restrike and warm-up times are reduced by up to 50%, minimizing downtime during power fluctuations.
• Optimized Burn Position: Designed for Base-Up operation (BU ±15°) to maximize light throw in high-bay and canopy fixtures.
• Professional Durability: Engineered for extreme temperatures and continuous operation in demanding industrial and stadium applications.

Technical Specifications

• Brand: Philips Pulse Start Metal Halide
• Order Code: 23259-5 (MS400/BU/ED28/PS)
• Wattage: 400W
• ANSI Codes: M155/M128/M135/E
• Base Type: E39 Mogul Screw
• Bulb Shape: ED28
• Color Temperature: 4000K (Cool White)
• Color Rendering Index (CRI): 68
• Maximum Overall Length (MOL): 8.31 inches
• Bulb Diameter (DIA): 3.5 inches
• Operating Position: Base-Up ±15°

Compatibility & Safety Notes

• Enclosed Fixtures Only: This lamp is rated for enclosed luminaires only. The fixture must be capable of containing hot lamp fragments in the event of a rupture.
• Ballast Requirement: Must be operated on a pulse start ballast with a high-voltage ignitor. Verify ANSI M155 (or compatible M128/M135) system