How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Kevin Your Own Question
Kevin
Kevin, Master Electrician
Category: Electrical
Satisfied Customers: 259
Experience:  15 yrs field experience with 11 yrs as self-employed contractor specializing in home repair\upgrades
18324022
Type Your Electrical Question Here...
Kevin is online now
A new question is answered every 9 seconds

I am an electrician that works for a LED lighting store installing

This answer was rated:

I am an electrician that works for a LED lighting store installing all types of LEDs. A couple months ago we installed LEDs in an assisted living complex. All the occupancy sensors and most of the LEDs are performing as expected. However we have a problem with the LEDs inside the residence's rooms. We seem are having a failure rate of over 25% and growing. We replaced all the bulbs A19s with new ones that have a higher power factor but are still getting huge failure. The bulbs start flickering, get hot, then burn out. Maintenance personal are not happy and the bulb manufacture will eventually stop replacing the bulbs. We want to fix this issue. I do know that each residence has it's own 20amp circuit. The recepticles and lights are on the same circuit. We suspect that the harmonic distortion is greater in the rooms since the other loads are also on the lighting circuit. I was also told by maintenance that the CFLs burned out quicker in the rooms prior to our work. One electrical engineer said to install Metal Oxide Varistors (MOVs) in the panels for each of the affected branch circuits, but I want a second opinion. I cannot find any information that this application has been used or will solve our problem. Any ideas or solutions will be greatly appreciated. Tim

Kevin :

Hello, and welcome to JA!!

Kevin :

What type of switch controls the lights in the resident rooms, and could you elaborate on the occupancy sensors?

Customer:

Just a general use snap switch for the residence. Occupancy sensors are for areas in the hallways and common areas. These areas are not where the problem is. Hallways and common areas are different branch circuits. I already checked all the normal issues like switches, voltage, connections ect. I am looking for someone who may have experienced failure of LED lighting on a large scale with high failure rate and possible solutions.

Kevin :

Alright. I will opt out of this question so that other experts can see it. But I will continue to give it some thought and if I can come up with another idea, I will let you know.

Customer:

okay thanks for trying. I think I need an electrical engineer to varify if my previous advice of using MOVs to suppress voltage spikes is the solution.

Kevin, Master Electrician
Category: Electrical
Satisfied Customers: 259
Experience: 15 yrs field experience with 11 yrs as self-employed contractor specializing in home repair\upgrades
Kevin and 2 other Electrical Specialists are ready to help you

Hi, I'm Norm and I'd like to help. I've looked up LED failure modes and two things keep coming up: excess temperatures and voltage spikes. Since the failures occur only in the resident's rooms, there is something unique in those rooms' electrical or physical environment. First, I would look at the fixtures themselves and possibly take some local temperature measurements inside the fixtures, comparing the readings with the LED manufacturer's specs. The electrical environment is tougher to evaluate, but one thing I would look for is inexpensive dimmer switches on other lights in the residences. Low-cost dimmers can produce repetitive spike voltages when they operate at less than full intensity. If there is no apparent temperature problem and no dimmers, I would pick a room or two and apply the recommended MOV';s or other surge protection on those circuits to see if it helps. If it does, obviously, the problem is voltage spikes. Please let me know what you think and whether or not you have the dimmer switches or other spike voltage sources present.

 

Here is a link to a paper on LED failure modes:

 

 

http://www.digikey.com/us/en/techzone/lighting/resources/articles/Understanding-and-Preventing-LED-Failure.html


Norm

Customer: replied 4 years ago.


Thanks Norm, this is what I needed. I appreciate the help. Tim

If I can help further, just return to this question and I'll get the message. Thanks.

Norm

Related Electrical Questions