Current requirements of UL 8750 for LED drivers provides for variability in test conditions such as load types, ambient temperatures and permissible temperatures during abnormal testing. This approach offers flexibility with the safety evaluation, but requires detailed review of the test program and partial testing of the LED driver when it is integrated into luminaires. This is also the case when an alternate LED driver is required for an existing luminaire design. In most instances, the flexibility in the certification program makes it difficult to source alternate LED Drivers without having to resubmit the luminaire for testing including the integral LED driver.
New UL Service Offering:
With the Class P driver program LED drivers are tested to determine that they operate safely under uniform normal & abnormal load and ambient temperature conditions. Additionally, certain construction features are controlled to facilitate interchangeability. The focus of the Class P driver program is how the LED driver will interface with its environment (LED luminaire) – mechanical and electrical. All Class P LED Drivers will operate at 90C case temperature or lower during normal operating conditions. Similar higher limits exist for abnormal condition testing.
The additional data gathered under the UL Class P certification will allow luminaire manufacturers to:
- Select LED drivers for new designs that have the desired parameters and limit the level of evaluation of the LED driver during evaluation of the LED luminaire.
- Use alternate Class P LED drivers, with similar characteristics, without an additional evaluation of the LED luminaire.
The Evolution of LED Drivers
1. Basic Certifications
- Listings and Recognitions, per Guide Cards
- Highest level of flexibility
2. Type TL
- Standardization of constructions features and test parameters
- Some restrictions (thermal)
3. Class P
- Builds off Type TL
- Eligible for Listing
- Minimal restrictions
- Uses Type TL as a starting point
- Many elements are identical to Type TL
- Standardized construction and testing requirements
- Modified Temperature Testing scheme
- Evaluates LED Driver under normal operating conditions and confirms that the LED Driver case temperature does not exceed 90 C
- Evaluates LED Driver case under abnormal testing and increased ambient conditions. Confirms these temperature generally do not exceed 110 C (with short excursions up to 150 C as with UL 935)
- No Measured Tref & Tref Max values to consider, no required Tc point
- Simplified interchangeability scheme
We have made a video to describe this UL class P certification.
Upowertek is the first company in China who pass UL Class P certification, please visit here for more UL class P LED Drivers