Philips 175W Switch Start Metal Halide Protected Lamp – M152/M137/O ANSI | 4000K | 14,000 Lumens | ED28 Clear | EX39 Base | Open Fixture | Model 281196

The Philips 281196 is a 175-watt switch start metal halide protected lamp delivering 14,000 initial lumens at 4000K cool white with CRI 65. M152/M137/O ANSI classification, EX39 exclusionary mogul base, O-rated open fixture compatibility, and base-up ±15° burn position make this a specification-grade HID replacement lamp for outdoor area lighting, high-bay industrial fixtures, parking lot illumination, and commercial security systems.

Quick Specs

• Brand: Philips
• Model / SKU: 281196
• Lamp Type: Switch Start Metal Halide (Protected)
• Wattage: 175W
• Operating Voltage: 132V
• Operating Current: 1.5A
• ANSI Code: M152 / M137 / O
• Color Temperature: 4000K (Cool White)
• CRI: 65
• Initial Lumens: 14,000 lm
• Design Mean Lumens: 9,100 lm
• Luminous Efficacy: 80 lm/W
• Rated Life: 10,000 hours
• Re-ignition Time: ≤15 minutes
• Base Type: EX39 Exclusionary Mogul
• Bulb Shape: ED28 Clear
• Operating Position: Base Up ±15°
• Fixture Rating: O-Rated — Open Fixtures
• Overall Length (MOL): 8.313 inches
• Diameter: 3.5 inches
• Max Bulb Temperature: 450°C
• Mercury Content: ≤27 mg

Product Overview

The Philips 281196 is a 175-watt switch start metal halide lamp rated for open fixture applications — a specification that sets it apart from most metal halide lamps, which require enclosed fixture housings. The O-rating (open fixture) allows installation in open luminaire designs, vented area lighting fixtures, and industrial high-bay housings without an enclosing glass lens or globe, provided the fixture is specifically rated for open metal halide lamps.

Switch start technology uses a separate ignitor (starter) in the ballast circuit to initiate lamp ignition — confirming your ballast includes a compatible switch start ignitor is essential before ordering. The EX39 exclusionary mogul base is physically keyed to prevent installation in standard E39 mogul socket fixtures that are not rated for metal halide technology, providing a built-in safety barrier against incorrect lamp installation.

Initial lumens of 14,000 at 4000K and 80 lm/W luminous efficacy represent a significant output advantage over 175W mercury vapor sources at the same wattage. Design mean lumens of 9,100 indicate significant lumen depreciation over the 10,000-hour rated life, which is typical for switch start metal halide technology. Re-ignition time after hot extinguishing is ≤15 minutes.

Why Choose This Product

• O-rated for open fixtures: Rated for use in open luminaires where enclosed housings are not present — expands application compatibility to fixture types that cannot accept standard enclosed-rated metal halide lamps.
• 14,000 initial lumens at 175W: Substantially higher lumen output than 175W mercury vapor sources at the same wattage — 14,000 lm vs approximately 7,800 lm for mercury vapor — with significantly better CRI (65 vs 50).
• EX39 exclusionary mogul base: The keyed exclusionary base prevents accidental installation in standard E39 mogul fixtures not rated for metal halide — an important safety feature in mixed HID lamp environments.
• 4000K cool white at CRI 65: Better color rendering than mercury vapor (CRI 50) — appropriate for commercial area lighting, parking, and industrial applications where improved color accuracy supports visibility and safety.
• 80 lm/W luminous efficacy: Competitive efficacy for switch start metal halide technology at 175W.
• Re-ignition ≤15 minutes: Relatively fast hot re-strike capability for switch start metal halide — reduces dark periods after power interruptions in outdoor and security lighting applications.
• Protected lamp designation: The outer protective envelope provides UV containment, expanding application safety in open fixture configurations.

Technical Specifications

Dimensions

Applications

The Philips 281196 175W switch start metal halide O-rated lamp is specified for commercial, industrial, and outdoor area lighting in fixtures rated for open metal halide operation:

• Outdoor area lighting – O-rated open fixture compatibility makes this lamp appropriate for vented area lighting poles, wall packs, and outdoor luminaires where enclosed housings are not used.
• High-bay industrial lighting – 14,000 initial lumens in 175W industrial high-bay and low-bay fixtures where metal halide is preferred over mercury vapor for higher output and better color rendering.
• Parking lot illumination – Commercial parking lot pole fixtures running switch start metal halide ballasts with M152/M137 ANSI ratings and open fixture housing designs.
• Security lighting systems – Perimeter and area security fixtures requiring high lumen output with improved color rendering compared to mercury vapor alternatives at equivalent wattage.

Replacing Your Current Metal Halide Lamp?

This lamp has several critical compatibility requirements. Confirm all of the following before ordering:

• ANSI code — M152 / M137 / O: These ANSI codes identify the specific electrical operating requirements for this lamp. Verify your existing ballast is rated for M152 or M137 operation. Metal halide ANSI codes are not interchangeable — installing a lamp with an incorrect ANSI code on a mismatched ballast will result in failure or safety hazard.
• Base type — EX39 exclusionary mogul: This lamp uses an EX39 exclusionary mogul base, not a standard E39 mogul. The EX39 base is physically keyed — it will not fit in a standard E39 socket that has not been modified for exclusionary lamp types. Verify your fixture uses EX39 lampholders before ordering.
• Burn position — base up ±15° only: This lamp operates in the base-up position only, within ±15° of vertical. It cannot be operated horizontally or base-down. Verify your fixture mounts the lamp base-up before ordering.
• Fixture rating — O-rated open fixtures only: Verify your fixture carries an O-rating for metal halide lamps. Do not install in enclosed fixtures — the thermal and UV characteristics of this lamp are designed for open operation.
• Start method — switch start: This lamp requires a switch start ballast with a compatible ignitor. Verify your existing ballast includes a switch start ignitor rated for 175W metal halide operation. Magnetic reactor ballasts without ignitors will not start this lamp.
• Re-ignition time: Allow at least 15 minutes for the lamp to cool before re-striking after hot extinguishing. Attempting re-strike before cool-down will fail — this is normal for metal halide technology.
• Lumen depreciation: Design mean lumens of 9,100 represent a 35% reduction from the 14,000 initial lumen output over 10,000 hours. Plan lamp replacement schedules to maintain target footcandle levels.

Ordering Information

• Brand: Philips
• Model / SKU: 281196
• Lamp Type: 175W Switch Start Metal Halide Protected
• ANSI Code: M152 / M137 / O
• Base: EX39 Exclusionary Mogul
• Fixture Rating: O-Rated (Open Fixtures)
• Case quantities and bulk pricing: Contact ADL Supply for volume orders.

Compliance and Safety

• 21 CFR 1040.30 Compliant: Yes — UV radiation performance standards for sunlamp products and ultraviolet radiation-emitting products.
• SOR/DORS/80-381 Compliant: Yes — Canadian Radiation Emitting Devices Regulations.
• Mercury Content: ≤27 mg — contains mercury. Dispose of in accordance with local and state lamp recycling regulations. Do not dispose of in general waste. For lamp recycling information, visit lamprecycle.org.
• UV Exposure Warning: This lamp emits UV radiation (UV-A: 5.69 mW/cm²). Use only in fixtures with appropriate UV shielding. A damaged outer envelope significantly increases UV exposure risk — replace damaged lamps immediately.
• Verify RoHS compliance status with manufacturer specification sheet.
• Verify California Title 20 / T24 compliance with manufacturer specification sheet.
• Verify Prop 65 warning requirements with manufacturer specification sheet.

ADL Supply recommends confirming all applicable compliance data with the Philips official product data sheet prior to specification or installation.