UL Jim

A company that put together a Classified retrofit kit can use any combination of LED module and LED driver by any manufacturer. We do check to make sure the LED modules are not being driven by an LED driver that has an output that exceeds the Class 2 limits. Under Classification, should a manufacturer want to change from their own LED driver to an LED Driver by another manufacturer, they can. We will document the change and no testing is required.

To start with there are two basic types of LED Drivers or power supplies. They are constant voltage and constant current. Constant voltage is the common power supply that most have been familiar with since they are used in most appliances and computer applications. However, the LED industry has been turning to Constant Current LED Drivers for optimum LED performance. Constant current is how neon power supplies, fluorescent ballasts and HID ballasts are designed. In the first one, constant voltage, the circuitry is designed to maintain the same output voltage, for example 12 V dc. This voltage level will be maintained up to a point where the load is too great which results in greater current and less voltage. However, as long as the output current is rated or less, the output will stay at rated. The second one, constant current, the circuitry is where the current is set for a value and regardless of the load, the output will adjust to stay at that current. For LEDs, the most common current levels are 350 ma and 700 ma since these are the most common current ratings for LEDs. As the number of LEDs added to the output increases, the voltage goes up to maintain the same current rating. However, the voltage limit can reach the maximum and adding more LEDs can result in less current output unless a protective device trips. Both of these types of LED drivers can be used interchangeable with LEDs, but not for the same LED load. For Class 2 LEDs, the load for each type will likely be different so this will have to be adjusted as needed to meet the rated output. As to LED Recognition and LED drivers the LED modules and the LED Driver are interchangeable. Class 2 LED Drivers are tested separately from Class 2 LED modules as individual components. They are not required to be evaluated by UL together as a system. In fact, there are many manufacturers of LED modules that are UL Recognized for use on a Class 2 circuit and the manufacturer neither makes a LED driver for them or provides one. For a Class 2 Constant Voltage LED driver - As long as number of LEDs does not cause the current rating of the LED driver to be exceeded, it is acceptable for powering any Class 2 LED modules. For a Class 2 Constant Current LED driver - As long as the current rating of the LEDs matches the current output of the LED driver and does not cause the rated voltage to be exceeded due to too much load, it is acceptable for powering any Class 2 LED Modules. As to Classification, this is only applied where a retrofit of an existing sign is involved. This covers a combination of LED Driver and LED modules with installation instructions on how to remove what is in a channel letter and replace it with LED drivers and Modules. The individual components are still Recognized individually. UL Classifies this combination rather than Listing it because there is no audit of how well the installer followed directions in retrofitting the sign. So we qualify the product as related to the effectiveness of the installation. Many manufacturers place the Classification Mark on their power supply for when it is used in for the retrofit Classification, but it is not exclusive. There are manufacturers who obtain LED Drivers and LED Modules from others and package them with installation instructions and as long as the instructions are correct, UL will extend Classification to the Retrofit Kit.

It is true that any LED system that exceeds the Class 2 limits must have the wiring and parts enclosed in an enclosure rated material. The reason LEDs have been Class 2 powered is for 2 basic reasons: 1) If the LEDs are powered by other than a Class 2 power source, they are required to be enclosed. In signs this means polycarbonate sign face. Acrylic sign faces are slow burning polymers that cannot qualify as enclosure grade material. Additionally, the sign manufacturer has to provide a marking on the inside of the sign warning service personnel of the need to use enclosure rated sign face material should the sign face be replaced. 2) If the LEDs are powered by other than Class 2, they must be mechanically secured in place. double sided tape would not be acceptable as should the tape let go, as it does at times, there is then high energy components mixing it up within the sign. This increases the likelihood of a fault and thus an arc to ground. Several years ago a manufacturer was insistent on using other than a Class 2 power source. The sign manufacturers time and time again were held up because the sign face was acrylic and unacceptable. This can be a real problem and it is the sign manufacturer who gets tripped up. Ventex has at least one product that I know of that is powered by other than Class 2. Therefore, make sure that when using Ventex products what the power source is and be prepared to adjust the sign face and LED securement method as necessary.

Regarding the inspection frequency being tied to the number of Listing Marks used, I am providing the Inspection Frequency instructions for signs. You will note that it identifies that all of the Sections of a Section Sign are collectively considered to be one sign. If however, a signle letter such as an "M" for McDonalds is a stand alone sign, then it counts as one sign. One inspection Applies to signs produced in lots of less than 50 units as follows. For section signs consisting of two or more sections that are not self-contained signs, all sections are to be considered as one unit. For letters or blocks of letters that are a self-contained sign, each one is to be considered a unit. For all other self-contained signs (e.g. neon window signs and menu boards) where 50 or more units possess a common construction that, except for sign face art work, are exactly the same (including size, shape and components used), the lots can be inspected once per quarter. In conclusion, additional inspections would not be triggered by 3 Section Signs as they would only be considered to be a total of only 3 signs. Also note that should you produce the same sign over and over again, such as an "OPEN" sign, even though you might make them by the thousands, they only need to be inspected once a quarter.

I am not going to try to convince anyone that the way the cost increases have been presented was anything but poor to a failure. Equally, the timing was terrible. It is unfortunate that all of these costs converged at the same time. I was equally shock when I found out. As a side note on the inspection fee, I know that this has been building for many years. The fee being charged to UL clients I understand, has not kept up with increasing costs over the last several years. Many might only see the increased cost of gas. However, all costs are going up including vehicles, food and it seems everything else these days. Since the Field Rep. is on the road all day, all of these expenses need to be covered along with their salary. Also, in a lot of ways costs have increased a little bit at a time on a more subtle daily basis. However, Inspection Fees are set once a year so it comes at you all at once. Compare the cost of a pizza between last year and this year. It is significant. As to the financial people in UL, when I asked how could they have made such a large increase, their answer is that the increase to the client is not as big as seen on the surface. With a $1060 annual maintenance fee and 4 $188 inspection fees the annual cost, not counting Listing Marks, is $1812 and now the annual cost is $1060 plus $1600 for a total of $2660. Therefore, they say comparing the yearly cost of $1812 to $2660 is a significant increase, but not as much as everyone thinks. Myself, I am technical only and want to keep it that way. I only provide these cost responses to provide as much as an explanation I can get from people in UL. Remember to not kill the messenger.

As to the timing of the cost increase, yes it is pretty dramatic and if it had been my choice, the increase would have been phased in gradually over a couple years. I agree that the many in the sign industry do not get down to the 1000th of an inch. Most of the time the minimum enclosure thickness is much less than sign manufacturers structurally need to use so the thickness is not exactly as critical as it seems. However, there are some who use the absolute minimum thickness specified in the standard. Even if you do not go down to the minimum, accreditors want to know precisely what went out the door in case there is a field problem. This need for all of the details such as calibrated equipment is not easy for me either. I have been with UL for 33 plus years and have seen UL go from little documentation to a lot of documentation. It forces me to try to stay flexible in my older age.

There are 2 concerns that have been expressed. I deal with the technical side of things, so I can only provide limited information on what is going on. Equipment and calibration - Product safety has become a global issue. This involves the need for third party testing labs to be internationally and nationally accredited. Accredition is important because without it, the mark of a third party testing lab such as UL is not acceptted. UL has always been accredited, but with the number of labs worldwide, more equipment documentation and calibration is being required to make sure that the results of testing and measuring are correct. Therefore, UL is being required to calibrate regularly all test equipment used to determine compliance. The requirement for equipment calibration is across the board for all industries. UL made it easier for the sign industry by allowing in-shop testing and measuring, versus sending the signs in to UL for testing. However, with this convenience comes the need for the sign industry to maintain the equipment they use for testing and measuring. Accreditation is not on a spot basis such that UL can say to the accreditors, the sign industry is not as global so they do not need to comply. The requirement is to make sure the that test equipment is accurate andnot an unreliable knock off piece of equipment. The cost increase is as I understand it to cover the expense for Field Sevices staff to be trained and to spend more time at the sign shop. Many of you probably have seen that Field Services is spending more time in your facillities. The extra time is for the purpose of stopping what some manufacturers who are cutting corners selling Listing Marks and other activities that make it more difficult fo the sign industry as a whole to be cost competitive from shop to shop. In the future, UL is also looking to providing better sign shop staff training. As noted above, I was not involved with the decision for the cost increases. I am sure there are number of reasons behind this across the board increase that has not been shared with me. What other industry do you know of makes house calls for only $188 or even $400.