Case Studies
Product Safety Case Studies
Resolve challenging product safety testing projects, especially when UL/ANSI standards or NEC requirements did not clearly address new or different technologies. Wilger Testing has had many successes in this area, so if your product is braving new trails, or you’ve been rejected by an NRTL, contact us to see how we can help. Our product safety staff is knowledgeable, experienced, and creative in selecting the best path your product can take to merit NRTL compliance and acceptance.
There are many reasons to use Wilger Testing’s services, foremost of which is to get your product marketed quickly with minimal hassle and at the lowest price. More importantly, our vast knowledge of UL/ANSI requirements is irrefutable, and when technology or time is a factor, we deliver time and time again. Take a look at the following cases that we have effectively resolved:
1986 Statue of Liberty Centennial Celebration
For the 1986 centennial celebration of the Statue of Liberty, a complete makeover was needed from the outside and inside, including new dramatic interior lighting. The task was to get the stainless steel low-voltage interior luminaires listed by an NRTL in four weeks’ time.
The time frame was tight as the low-voltage transformers used were not NRTL-evaluated as components. We were expecting delivery of the luminaires to our laboratory when we were notified that the truck delivering the lights was hijacked somewhere in Brooklyn, NY. The manufacturer had no choice but to remake the samples.
Lady Liberty to the Rescue
This is where the whole project went from difficult to crazy, as we were told that we now had one week to test the luminaries and the unlisted transformers and have the NRTL list them. The insulation system on the transformers was a Recognized Class 130 system, so the key was to have the temperature tests on multiple designs remain at 110 degrees C on the coils. To our surprise, Lady Liberty luck came our way as the tests, reports, and unlisted transformers were all done on time, allowing us to meet the shipment date.
The Hickey Freeman Field Problem
The owner of Hickey Freeman reported lamp and transformer failures of approximately 50 multi-head MR-16 low-voltage halogen luminaires. Each luminaire had 8-17 lamp heads, and the installation was approximately two years old. The luminaire manufacturer, in good faith, paid to replace all of the lamps and transformers. Six weeks later, the customer complained that the lamps and transformers were failing again. Wilger Testing Company was contracted by the luminaire manufacturer to investigate.
The fixtures in question were installed at the Hickey Freeman Store on 5th Avenue in Manhattan, NY. We met the store manager, the lighting designer responsible for the installation, and the sales representative for the luminaire manufacturer at the job site.
We examined all of the luminaires, including their installation, and found that three issues needed to be addressed, all of which involved improper luminaire maintenance as described below:
* All four non-operational transformers came from the original installer but were missed by the electrical contractor when the luminaires were retrofitted with new transformers.
* Twenty-five of the 50W IR MR-16 type lamps were from the original installer but were either nearing the end of their shelf life or had already burned out. We knew that the lamps were not replaced when the luminaires were retrofitted because a different set of lamps was used.
* One of the new transformers was installed incorrectly. The luminaires insulation detector was removed from its intended location and installed in the transformer knockout. Type Non IC insulation detectors are of the self-heating type and operate at temperatures in excess of 100°C. The heat being generated by the insulation detector was causing the transformer to cycle off on thermal overload. Once the insulation detector was installed as intended, the transformer operated properly.
Cost Savings
Because we were able to determine the root cause of the lamp and transformer failures, we saved the luminaire manufacturer the cost of having to replace the entire installation. We also resolved the concerns of the store owner and the lighting designer.
Inside CNN Field Problem
A customer reported HID electronic ballast failures for recessed multi-lamp luminaires. The fixtures in question were installed at the Inside CNN Store at 10 Columbus Circle in Manhattan, NY. Wilger Testing Company was contracted by the luminaire manufacturer to determine the root cause of the ballast failures.
We examined the luminaires, including their installation, and determined the following:
* There were (20) three-lamp HID luminaires recessed in a drywall ceiling around the perimeter of the store. The ceiling was approximately 12 feet in height, and the space was climate-controlled.
* Each of the luminaire heads was powered by an electronic HID ballast, with 35W PAR20 metal halide lamps being used.
* Of the (20) luminaires, (15) had one non-operational lamp, one had two non-operational lamps, and another one had three non-operational lamps. A total of twenty (20) lamps were found to be non-operational.
* Before removing the luminaires from the ceiling to check the wiring, we shut them off and swapped one of the known good lamps with one of the non-operational counterparts to rule out any fault. When we energized the luminaires, the same lamp heads remained non-operational, which effectively ruled out a lamp problem.
* We then removed the recessed housing from one of the luminaires to check the wiring, and noticed that the factory wiring was in accordance with the ballast manufacturer’s wiring diagram. We also noticed that the building ground was not attached to the pigtail ground in the luminaire. The electronic ballast installed in the luminaire must be grounded to operate properly. Additionally, without a proper ground wired to the luminaires, the possibility of a shock hazard was high.
After properly grounding the luminaires, all of them operated normally, and the customer reported no further issues afterward.
Field Problem at White House Room 350
The project manager in charge of the remodeling project for Room 350 of the White House reported mass lamp failures in the installed recessed luminaires. We were contracted by the luminaire manufacturer to validate the issue and offer a solution.
With this project, time was of the essence because the room was to be used for televised presidential addresses while the Oval Office was being remodeled. We had three weeks to determine the cause of the problem and implement a solution. Below was our finding:
*After meeting the general contractor in charge of the installation, the senior field tech for the dimming control manufacturer, and the White House representative, we examined the fixtures in question, which were composed of 19 three-lamp AR-70 recessed luminaires, 2 four-lamp square AR-70 luminaires, and 33 one-lamp MR-16 recessed luminaires. All of the luminaires were powered by the same model integral electronic transformer. The luminaires were recessed in a drywall ceiling and wired to multiple 20A circuits of a dimming system. The ceiling was approximately 12 feet in height, and the space was climate-controlled with excellent humidity control.
* According to the contractor, he had replaced 200+ AR-70 lamps since the fixtures were installed six months prior, and they were burning out from the first day of operation in random order.
* Except for two of the one-lamp MR16 luminaires, all the other lamps were operational at the time of the meeting.
*Due to the delicate nature of the ceiling finish, we only examined three luminaires, but upon examining them, we determined that they were constructed, wired, and installed properly.
* We monitored input voltage to the luminaires and measured transformer and lamp envelope temperatures. Both voltage and lamp envelope temperatures were well within specifications.
* Since the fixtures were wired and operational, we turned our focus to compatibility issues between the low voltage transformers and the dimming system. We contacted the transformer manufacturer to see if they have had compatibility issues with the installed dimming system. They confirmed that there have been compatibility problems involving the model dimming system installed on site.
* During shutdown, the dimming system hit the transformer with a split-second ring wave pulse voltage, which stressed the transformer and instantly burned out the lamp. We then arranged a face-to-face meeting with engineers from the transformer and dimming system manufacturer to develop a solution that will not require the replacement of the luminaires or the dimming system and will not damage the room in any way.
* We determined that the pulse can be eliminated by adding a choke coil at each luminaire feed. This was a relatively low-cost solution to the problem in the control room.
Customer Comment
“Wilger Liaison has supplied us with unprecedented services over many years. Their expertise is invaluable and allows us to develop new designs, modified and custom fixtures in a timely fashion. Their professional services always come in handy whether they are specific to our listings, codes, troubleshooting, or the like. We highly recommend them as they have always been valued as a close partner in our industry.”
– Jerry Ahlin
EVP