Philips Lighting 928601143590 C100S54/M PH 12PK

At 100 watts the Philips HPS series uses the BD-17 envelope. The BD-17 shape covers the 35, 50, 70, 100 and 150 watt ratings in the series, so if a fixture already takes a 70 or 150 watt lamp of this family the 100 watt drops into the same physical space. The larger ED-18, T-14 and ED-37 envelopes only appear at 225 watts and above.

Not without changing the ballast. High pressure sodium lamps are matched to a wattage-specific ballast, and a 150 watt HPS ballast will not correctly operate a 100 watt lamp even though both use the same BD-17 envelope in this series. Match the lamp wattage to the ballast label, or change the fixture ballast at the same time.

It is sold as a 12 pack, which is why the catalog designation reads C100S54/M PH 12PK. That suits a property manager or MRO stockroom relamping a run of parking lot or warehouse fixtures in one pass rather than buying singles.

Rated average life is 24,000 hours. On a dusk to dawn photocell burning roughly 4,000 hours a year, that is about a six year relamp cycle, which is the main reason HPS still gets specified for pole-mounted security and roadway lighting where access is expensive.

HPS remains a low cost per lumen option: this series runs up to 140 lumens per watt with a 24,000 hour rated life, which is why it is still common in security, roadway, warehouse and industrial use. The trade-off is color, HPS produces the familiar amber light with poor color rendering, so it is a poor choice anywhere color recognition or interior occupant comfort matters. Where the existing ballast and fixture are sound, relamping with HPS keeps cost of ownership down; where the fixtures are being replaced anyway, that is the point to evaluate a different source.

At 100 watts, HPS lamps of this type use a mogul screw base, and the series is offered across a range of bases and wattages. Check the socket in your fixture against the base on the lamp you are replacing before ordering a case of twelve, since the same wattage family can be built on more than one base.