What’s with the red LED?

November 5, 2019
Tech Tuesday

If you know RIB® relays, you’ll be familiar with our use of the red LED. However, not everyone knows what the red LED means on the relay devices we offer. Let’s shed some light on this sometimes confusing detail!

First, the aim with RIB relays, and Functional Devices as a whole, is to make installation easy and convenient for the field technicians and installers. The benefit of RIB relays is that they’re offered in pre-packaged, pre-wired, and UL approved formats. This saves time and money when it comes to installation. One way we thought of passing savings on to you is by incorporating the red LED on our relays.

Typically, some kind of visual indicator of relay coil status is incorporated in any relay installation. This visual indicator says to the outside world, “Hey world, my coil is being energized!” Over the years, Functional Devices has listened to feedback, determining that our relay products are higher quality when an LED is added to the construction.

Contrary to what a red light typically means (i.e. stop, warning, etc.) the red LED on our RIB relays signifies that the coil of the relay is being energized. It does not mean that there is something wrong with the RIB relay. That can be an important detail when debugging the system using the RIB relay. For example, let’s say that a RIB2401B relay is controlling a fan motor. The building automation system (BAS) is calling for the fan to turn on. The red LED is illuminated, however, the fan is not turning. What could be happening in this system?

  • Is the motor is locked up?
  • Is the power to the motor is down?
  • Is the motor is too large of a load and the relay contacts seized?

While that list is not exhaustive, it certainly narrows down the possible issues which then helps to debug the system. When the problem is determined quickly, it means a solution may quickly be implemented to bring everything back to normal.

I hope that helps to clear up any confusion about the red LED on the RIB relay devices we offer. There are a few exceptions to this rule in some products, though, so if you have a question then give Technical Support a call!

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About the Author

Meet Samuel Klennert – you can call him Sam. He was born and raised amongst the farmland of Indiana, which included corn, soybeans, and sometimes wheat. Sam graduated from Purdue University with a Bachelors degree in Electrical and Computer Engineering Technology in 2015. He has a focus in analog circuitry and power electronics, but he’ll give software a try from time to time – just not that digital witchcraft!

Outside of work, Sam enjoys outdoor activities including (but not limited to) hiking, mountain biking (or just really-big-hill biking), and camping. Call Sam for tech support today – he’ll give his best effort to any task at hand!