What is LBC?

Lamp/ballast compatibility (LBC) is a phrase used to describe the working relationship between a ballast and a HID lamp. In most cases this phrase often refers to electronic ballasts operating HID lamps.

LBC is a hot topic because electronic ballasts can fail to consistently operate HID lamps, mainly Metal Halide lamps. Many people think the lamp is supposed to be compatible with the ballast. In reality it is the other way around and the ballasts must be compatible with the lamp.

LBC is a big concern with growers because if the lights are off, plants won’t grow. Understanding the basics of how ballasts operate HID grow lights is key to troubleshooting your lighting system when it is not operating properly.

The ballast is the power supply. In essence the ballast is the engine driving the lamp. Without the ballast the lamp is useless.

The lamp is a receiver of power. The lamp does not send any signals to the ballast or communicate in any way with the ballast. The lamp just sits there and takes what the ballast provides.

With that said, HID lamps do have voltage requirements or standards that each ballast must meet for startup and steady operation. Different lamp types and different wattages have their own standards for the ballast to provide.

This video demonstrates LBC

Signs of LBC

Potential signs of lamp/ballast compatibility include:

  • A brand new lamp that will not light up
  • A brand new lamp that starts up for a second, then shuts off
  • A brand new lamp has been working fine for a period of time and won’t light up any more
  • A lamp that doesn’t get to full brightness
  • A lamp that is a couple of months old and works inconsistently
  • A lamp that is less than a year old and has completely burned out

These are classic examples of lamp/ballast compatibility issues. The best way to troubleshoot the problem is to try running the lamp on a different ballast. If the lamp starts on the different ballast you know there is a problem with your ballast.

Timers and control systems have also been known to prevent ballasts from operating lamps properly. It is a good idea to take the timer/controller out of the system when troubleshooting. You may find the problem is within the timer/controller.

In most cases the ballast is at the center of the issue. Many of today’s popular electronic ballasts are designed to operate HPS lamps and struggle to operate Metal Halide lamps consistently.