At GreenStar, we design our products to the highest quality and use condition standards.
Unfortunately, even with the highest quality standards in place, poor electrical line maintenance and power quality issues can result in catastrophic damage to LED luminaires.
Utility distribution lines that provide power to streetlights were installed to manage street lights from a different era. They were generally designed to power high pressure sodium (HPS) street lights, not LEDs. LED streetlights are essentially mini computers with sensitive electronic components that are sensitive to power fluctuations that deviate from the voltage rating.
Updating the distribution grid can be challenging from a load design perspective, expensive and time consuming. Utility providers have therefore placed the burden on manufacturers to help protect their LED luminaires in these harsh power quality environments.
GreenStar provides one of the most robust warranties in the industry and integrates high-quality surge protection in all of our luminaires to protect against high-voltage events, such as lightning strikes. Surge events are analogous to a heart attack. They can kill quickly. When the voltage rises above the rated clamping voltage, the surge protector suppresses the excess voltage to prevent it from causing harm. Specifically, the internal components called metal oxide varistors (MOVs) absorb the excess voltage and divert it to the ground wire, preventing it from reaching the connected equipment. When connected in serial, surge protectors will continue to absorb the energy in a surge and divert the extra voltage into the ground until they finally reach their end of life rating at which time the surge protector will fail and open the circuit therefore preventing the flow of all power to the streetlight’s LED driver. The surge protector is a consumable device, like the brake pads on your car. It is much more cost effective to change the surge protector than replace the entire LED luminaire.
However, surge protectors do NOT protect against under voltage (sag) or over voltage (swell) events. Sag and Swell events are analogous to cancer, they kill slowly over many years. Under voltage (SAG) events occur when the average voltage of a three-phase power system drops below intended levels and is sometimes referred to as a brown-out. Electro-mechanical devices are designed to be operated at very specific voltage levels. If these devices are allowed to operate at reduced voltage levels they will draw higher currents. The increase in current causes increased heat which can damage sensitive components in LED drivers causing them to fail prematurely. Often times when this happens, component failure occurs causing LED lights to blink, cause “day burners” due to a damaged photocell or the lights may stop working completely. Over voltage (swell) events are the opposite of sags and describe surges in voltage of 10% or more above normal or recommended usage. Swells can occur when a large load is turned OFF and voltage on the power line increases for a short period of time. The principal causes of swells are switching events such as the connection or disconnection of a current and short-circuiting to the ground. Surge protectors are unable to protect against SWELL events due to their clamp ratings being higher than the swell event. For example, a surge protector may have a clamp rating of 600v. An electronic component may have an operating range of 300v. There is a gray area of 300-599 volts that the surge protector allows voltage to pass through prior to clamping taking place, which can cause serious damage to electronic components.
Sag, swell and surge events can happen when tree limbs hit distribution lines, when ice or snow sits on distribution lines and even when car wrecks knock over street light poles. These are all instances that can’t be controlled, yet the LED light is expected to work in these dirty power environments for over 15-20 years without issues. GreenStar has the solution to protect against under voltage (sag) and over voltage (swell) events with our Autonomous Voltage Interrupter (AVI).
Customers can feel confident that GreenStar luminaires are protected against even the most rigorous electrical infrastructure design or poor power quality environments, surge, swell and sag voltage events.
Take a moment to learn how the Autonomous Voltage Interrupter (AVI) works by watching this video.