Violating my UL Listing...
I hear this alot. We sell Initiating Devices, Notification Devices, even some non-propriety Addressable SLC Devices. On rare occasions we can source hard to find parts for obsolete Fire Alarms (new in the box, never used).
Inevitably, someone will ask if swapping out a module or component will "violate" their UL Listing by making a change in the panel.
The short answer is No!
Here is how this works, UL, FM, ETL, any of the National Recognized Testing Laboratories (NRTL) work off of a set specification for the product they List/Approve/Whatever. In the case of Fire Alarm Control Systems, it is UL864 (and ANSI Spec). This tells the manufacturer everything they need to know about how a control must function, how it can be interfaced and programmed and how each circuit must be designed so that it is safe and relaible.
Soup to nuts, so to speak, all aspects of the control is designed and later on, tested to the infomation in the UL864 Document. This includes the documentation included in the control so that you know what Notification Appliances, Initiating Devices, SLC Devices, etc... are approved or Cross Listed with the panel. Thus the NRTL assumes that the technician/installer are working per NFPA 72 which states they must be factory trained, are licensed to work on Fire Alarm and will work in a good workman-like manner.
SO what does this mean to the tech in the field that is getting ready to change out a power supply, zone card or even an LCD Display? Well the NRTLs test the product and Lists or Approves it so that when the manufacturer ships it out, it is a safe and approved product. And that is the end of the story.
Once the panel is packed up with all of its documentation and leaves the shipping dock, the power of the Listing ends. NRTLs only guaranty that the product with their label on it has been manufactured per their records, wich include the component lists, document lists and the assembly and testing proceedures the product went through before it went into the box. As long as you are replacing a module/card/board/component with an exact duplicate module/card/board/component, the NRTLs couldn't care less...
Now if you are putting in a new motherboard and it is a different revision (hardware or software, it doesn't matter) you can rest assured that the manufacturer didn't ship it without the NRTL approving it first and they would have tested its backward compatibility to your system prior to sending it out to you.
I hope this clears this up for you. I have had many converstaions in the past with employees of the various NRTLs and they all say the same thing, the key is to always replace parts with new parts and be factory trained to do the work, which is just good common sense.
Have a Life Safety Day!