Product Overview
GE 92585 70W CMH G8.5 Lamp - 3000K Ceramic Metal Halide - ANSI M139/C139
The GE 92585 Constant Color is a high-performance 70W Ceramic Metal Halide (CMH) lamp featuring a G8.5 2-pin base and ANSI M139/C139 compatibility. Delivering 6,200 lumens of warm 3000K white light with 80+ CRI, this T4.5 tubular lamp is ideal for high-end retail displays, museum lighting, and commercial architectural applications. With a 15,000-hour rated life and superior color stability, it offers consistent illumination throughout its lifespan.
Technical Specifications - GE 92585
Electrical
| Manufacturer Part Number | 92585 |
|---|---|
| Wattage | 70 Watts |
| Operating Voltage | 90 Volts (Provided by ballast) |
| Base Type | G8.5 (2-Pin Ceramic) - 8.5mm spacing |
| ANSI Ballast Codes | M139 / M139E / C139 |
Performance
| Color Temperature | 3000K (Warm White) |
|---|---|
| Color Rendering Index (CRI) | 80+ (Very Good) |
| Initial Lumens | 6,200 lm |
| Efficacy | 88.6 Lumens per Watt |
| Rated Life | 15,000 Hours (L70) |
Physical
| Bulb Shape | T4.5 (Tubular) |
|---|---|
| Maximum Overall Length | 3.37 inches (85.6mm) |
| Bulb Diameter | 0.56 inches (14.2mm) |
| Burning Position | Universal (Any) |
| Arc Tube | Compact T4.5 Ceramic |
Compatible Ballast Systems - ANSI M139/C139
⚠️ Important: This lamp requires specific ANSI M139 or C139 rated pulse start ballasts (70W). Operating with incorrect ballasts will void warranty and may cause safety hazards.
GE Recommended Ballasts:
- GE GEMH70 series electronic ballasts (M139 compatible)
- GE CWA/RWA magnetic ballasts rated for 70W CMH
Compatible Third-Party Ballasts:
- Philips Advance: Xitanium 70W CMH electronic ballasts
- Osram: PT-FIT 70/220...480 I (M139/M85 family)
- Sylvania: Quicktronic QTP6C70
- Universal Lighting: UC70 series (M139 rated)
Compatible Replacements & Industry Equivalents
The GE 92585 (G8.5 base, 70W, 3000K) is electrically compatible with:
| Brand | Part Number | Notes |
|---|---|---|
| Philips MasterColor | CDM70/TC/830 (#373738) | T6 shape, G8.5 base |
| Osram Powerstar | HCI-TC 70/830 WDL PB G8.5 | Warm Deluxe, 3000K |
| Sylvania Metalarc | MC70TC/U/G8.5/930PB (#64825) | 930 = 3000K |
| ILCOS Standard | MT/UB-70/30/1B-H/E-G8.5-13/57 | International coding |
| Ushio | UM70/G8.5/TC/830 | JP manufacture |
Note: All listed lamps operate on ANSI M139/M139E/C139 ballasts and provide equivalent 6,000-6,200 lumens at 3000K.
Safety Information & Compliance
⚠️ UV Radiation Hazard
- Emits UV radiation during operation
- Must use in enclosed fixtures meeting UL 1571/1574
- Requires UV-blocking lens or glass shield
- Not for residential living areas with prolonged exposure
- Automatic shutoff recommended for envelope breach protection
? Operating Temperatures
- Arc tube operates at extremely high temperatures
- Allow 15-minute cool-down before handling
- Use only high-temp ceramic G8.5 sockets
- Maintain minimum 3-inch clearance from combustibles
- Maximum base temperature: 250°C (482°F)
? Standards Compliance
- ANSI M139 / C139 compliant
- UL 1571 / 1574 enclosure requirements
- Universal burning position certified
- RoHS compliant construction
Premium Features & Technology
- ConstantColor™ Technology: Maintains 3000K ±100K throughout 15,000-hour life. Unlike standard metal halide, does not shift toward green/blue.
- Compact T4.5 Arc Tube: Ceramic discharge tube provides precise optical control for accent and display lighting.
- Superior Color Maintenance: 80+ CRI maintained at end of life vs. degradation in standard MH lamps.
- UV-Block Outer Jacket: Enhanced safety with UV-filtering quartz envelope (still requires enclosed fixture).
- Universal Burn Position: Operates reliably base-up, base-down, or horizontally.
- Pulse Start Efficiency: Faster warm-up (2-3 minutes) and better lumen maintenance than probe-start systems.
Professional Applications
High-End Retail
- Merchandise display cases
- Fashion boutique accent lighting
- Jewelry counter illumination
- Window display spotlights
- Track lighting systems (G8.5 compatible)
Museums & Galleries
- Artifact display lighting
- Artwork accent (when UV-filtered)
- Sculpture illumination
- Rotating exhibit track systems
- Color-critical exhibition spaces
Commercial & Architectural
- Hotel lobby accent lighting
- Restaurant ambiance lighting
- Corporate reception areas
- Recessed downlights
- Wall washing applications
Frequently Asked Questions
What is the difference between G8.5 and G12 bases?
The G8.5 base on this GE 92585 has 8.5mm spacing between pins and is used for 35W-70W CMH lamps. G12 has 12mm spacing and is typically for 70W-150W lamps. They are not interchangeable. Verify your fixture socket: G8.5 is smaller and more compact than G12.
Can I use this lamp in an open track light?
No. This CMH lamp emits UV radiation and operates under high pressure. It must be used in fully enclosed fixtures with UV-filtering glass. Open track heads expose users to harmful UV and risk of arc tube rupture. Look for "enclosed rated" or "CMH compatible" fixtures only.
What does ANSI C139 vs M139 mean?
ANSI M139 is the standard code for 70W pulse start metal halide systems. C139 is often used interchangeably or refers to the ceramic metal halide variant of the same electrical specification. Your ballast should be labeled M139, M139E, or C139 for compatibility with this GE 92585 lamp.
How does ConstantColor compare to standard Metal Halide?
GE's ConstantColor uses a ceramic arc tube instead of quartz. This maintains stable chemical composition, preventing the color shift (greening) common in standard MH lamps. Standard MH may shift 1000K+ over life; ConstantColor stays within 3000K ±100K (2900-3100K) for its entire 15,000-hour life.
Is 80+ CRI good enough for art galleries?
80+ CRI is acceptable for general gallery lighting, but critical color evaluation (painting restoration, photography studios) typically requires 90+ CRI. For general museum illumination where budget is a concern, 80+ CRI provides good color rendering. For premium exhibitions, consider 90+ CRI CMH or LED alternatives.
