Fertraso - 400W HPS Lamp

This 400 watt high pressure sodium lamp gives 52,000 lumen at 2000 kelvin, with an E40 cap and a nominal life of 24,000 hours.

The lamp on its own does nothing

An HID lamp is not a device you screw into a socket and switch on. It is a gas discharge tube, and it needs something to strike the arc first and then limit the current. That is the ballast, and without one either nothing happens or something breaks.

A ballast does two things in sequence. At switch-on the igniter delivers a voltage pulse high enough to make the gas conduct. Once the arc is burning the lamp behaves as an ever-decreasing resistance, so without limiting, the current would keep climbing until the lamp failed. The ballast holds that current at the value the lamp was built for.

In practice that means three things. The wattage must match: a 400 watt lamp belongs on a 400 watt ballast and not on a 600. The type must suit, because HPS and metal halide make different demands on ignition, though many modern electronic ballasts handle both. And the ballast is a separate purchase, because in this corner lamp and ballast are sold apart and do not last equally long.

Electronic ballasts are quieter, lighter and more efficient than the old coils, and are often adjustable in steps. If you still have a coil ballast this lamp runs on it perfectly well, as long as the wattage matches.

Technical Specifications:

• Model: 21.216
• Power: 400 W
• Type: high pressure sodium, HPS
• Colour temperature: 2000 K, warm
• Luminous flux: 52,000 lumen
• Cap: E40
• Life expectancy: nominally 24,000 hours
• Ballast: 400 W required, not included

Frequently asked questions

Can I run this lamp on a 600 watt ballast?
No. Lamp and ballast wattage must match.

Will it run on an old coil ballast?
Yes, as long as it is a 400 watt HPS one. Electronic is quieter and more efficient, but not a requirement.

Why is the ballast not included?
Because lamp and ballast do not last equally long. You replace the lamp several times on one ballast.

Will a metal halide lamp run on the same ballast?
On many electronic ballasts, yes. Check per unit, because it does not hold everywhere.