The Energy Standards specify in §110.11 that low-voltage dry-type distribution transformers may be installed only if the manufacturer has certified model information to the Commission as required by the Title 20 Appliance Efficiency Regulations. In addition, §110.1 specifies that appliances regulated by the Title 20 Appliance Efficiency Regulations may be installed only if the appliance fully complies with those regulations, and both medium-voltage dry-type and liquid immersed transformers are included in the Appliance Efficiency Regulations. Products that are successfully certified as complying with Title 20 are listed in the Appliance Efficiency Database along with their efficiency.
This means that builders, building design team engineers, or owners who wish to install a distribution transformer will generally need to check the Appliance Efficiency Database to confirm that the model they are selecting has been certified by its manufacturer as required by law. A link to the Database is below:
https://cacertappliances.energy.ca.gov/Pages/Search/AdvancedSearch.aspx
The following types of transformers are exempt from certification requirements, and are not required to be listed in the Database:
1. autotransformers;
2. drive (isolation) transformers;
3. grounding transformers;
4. machine-tool (control) transformers;
5. nonventilated transformers;
6. rectifier transformers;
7. regulating transformers;
8. sealed transformers;
9. special-impedance transformers;
10. testing transformers;
11. transformers with tap range of 20 percent or more;
12. uninterruptible power supply transformers; and
13. welding transformers.