The DLC understands that most refrigerated and display case lighting products are sold as systems with multiple units attached to a power supply. Occasionally, this system architecture has also been seen on other product types as well. DLC does not consider these types of products as DC or PoE products, and these products are not covered by that policy. For these products, there is no provision for qualifying a product to the DLC QPL with an unspecified or field-specified driver. Qualifications and listings are always driver-specific. If a specific driver does not come with the product, model-numbers will include driver information on the QPL.
 
The DLC lists these products, when qualified, with module-level performance data for light output characteristics. Individual modules connected alone on the same power supply used in the system are understood to not perform the same as they would when the total system is connected to the power supply because of efficiency variance based on the load on the power supply. Therefore, DLC evaluates and lists metrics where driver loading plays a meaningful role (i.e. efficacy and power quality metrics) at the system-level, including appropriately loaded power supplies.

To obtain data that is accurate to all relevant metrics for an individual module and appropriately-construct the system, the DLC requires testing conducted as follows:

• Each individually unique module should be tested alone using the goniophotometer method according to LM-79 for light output and light distribution measurements. From this testing, the DLC will obtain the light output and light distribution (zonal lumen density) information.
• Additionally, the worst-case system configuration should be tested (using either the integrating sphere-spectroradiometer method or gonio-spectroradiometer method in accordance with LM-79.,for the other necessary metrics: efficacy, color, power quality, etc. This may involve multiple photometric measurements to appropriately measure the total light output of the system for efficacy calculations, along with the electrical measurements for the system as a whole. The DLC will use the measurements on this system to evaluate compliance with the DLC requirements, and determined listed test performance information, for these metrics.
  •  The worst-case system will be the configuration in your product line that would result in the lowest efficacy – typically at the worst (smallest) loading conditions for a given power supply/driver – that would meet the DLC requirements.

For listing purposes, DLC will also include a note in the “Notes” field on the QPL describing to QPL end-users the minimum system size necessary to meet DLC requirements, as based on the information provided in the application materials.

Applications for modular products with external power supplies are held to the same driver variation policies detailed in the Family Grouping policy.