Electrical Troubleshooting Quiz — April 19, 2022

Your firm got a call from a commercial building manager. Throughout much of the winter, tenants complained that the parking lot lights were often so covered with ice that hardly any light came out. Now that the weather is warmer and the lot is safer to work in due to the absence of winter ice, they want your firm to determine the cause and provide a price quote on fixing it. Your boss assigned you to look into it and try to make that determination. What are some issues you need to investigate?

Ask the right questions

Actually, looking at the lights requires getting a bucket truck and some people onsite. Before undergoing that expense, you may be able to identify the problem with a little office-bound investigation that requires no equipment other than a pen and notebook. 

First, ask the manager if they have any photos showing the iced-up fixtures. Odds are they don’t but just asking this will help underscore the need to capture event data when there’s a problem. If they have photos, you can readily identify which lamps to focus on. If they don’t have photos, they probably never bothered to find out which lights were presenting this problem. It could be all the lights. But ask the question because the answer may save you time if you end up needing to send a bucket truck and crew out there.

Next, ask them if they have upgraded their lighting at any time in the past two years. If they say they have, ask to look at the purchase order so you can see what types of lamps were purchased. You are specifically looking for LED. The problem with outdoor LEDs is they don’t get hot enough to melt ice. That’s why their use as markers on air traffic control towers is prohibited.

Also,  ask when was the last time they had a relamping company change any of the outdoor lights. If they don’t know, then it hasn’t been done. So, another possibility is the existing lighting is nearing the end of its life and simply isn’t bright enough. People may have mistaken the lower output for iced-up lights because they saw snow and ice on the ground and just drew that conclusion. Stare up at a light in the dark, and you’ll understand why seeing what’s actually there is unlikely to happen.

If you have identified LEDs in use for this application, then you have also identified the problem. If the LED upgrade consisted only of a direct lamp replacement, the cheapest and easiest solution would be to switch to a different lighting technology. If they have replaced the entire unit to do the upgrade (generally the best approach), you should contact the manufacturer to see if they have any add-ons or other solutions; get a price estimate from them.

This is about all you can do without getting a bucket truck onsite. If the office-bound investigation doesn’t show LEDs were installed, you will need to examine the lighting. This is best done during nighttime conditions.

Physically check the lighting

Begin by measuring the lumens output and note the height and location from which each measurement was made. Compare the readings to what they should be for sufficient illumination. As for ice, any lighting technology other than LED inherently takes care of that problem so it’s not something to investigate unless there is water ingress to the fixture and that’s what’s icing up.

To go further, you will need to get a crew and bucket truck out there to start looking at lighting units one at a time. Look for the most common problem with diminished light output: dirty lenses. Note whether the dirt was only on the outside or if it was also on the inside. Cleaning the lenses will likely solve the problem. Clean one unit and look for signs of water ingress while you’re up there (cracked lens, cracked housing, water stains, rust stains, etc.).

Then take new lumen readings from the same height and location as before. If lumens are significantly greater, you have found one problem. But even with clean lenses, the lamps might not put out enough light. Replace that lamp with a new one and take readings again. If the replacement lamps put out significantly higher lumens, you have found another problem. Repeat with a couple more fixtures to prove it’s not a one-off.

But if none of the preceding steps results in greater light output, you’ll need to go deeper into troubleshooting. Maybe it’s the line voltage, the ballasts, or an adjustable shade issue.

The most likely solution is the customer needs to relamp the whole parking lot and then get set up on an appropriate relamping schedule for lighting maintenance — and also have those lenses cleaned or replaced. If your firm doesn’t do relamping, you can charge the customer for the troubleshooting and recommend a firm that does.