After many years of working with various motor manufacturers, it is still surprising that so few customers understand the UL process. And for many of us, including our customers, it is not what we might have thought we were getting.
I have known several people to use laboratories such as QPS, Intertek, International Certification Services or others. All of these companies can perform Electromagnetic Compatibility (EMC), Conformity Marking (CE), Electrostatic Discharge (ESD), Canadian Standards Association (CSA), Underwriters Laboratories Standards (UL). This means that these companies can test to the “standard”, but it does not mean that the product or component is “listed” or “certified”. ONLY UL can List or Certify a product. Listing typically means a component, Certification is for all of the components tested together in the system or final product.
As it turns out, according to UL, only UL can provide a UL approval / listing with UL doing the testing. QPC, Intertek and other like companies only test to UL specification standards but can’t provide the UL sticker or say the product is UL approved / listed, only that it’s been tested to UL standards.
If your motors have UL Listed electrical insulated components (lamination bonding, stator insulation, magnet wire, varnish, motor leads, shrink tubing, cable, splices, tape, etc.) you might have a motor that is UL Compliant. Nothing more.
If any customer requires UL Certified motors, we can perform these tests at the customer’s expense. These UL tests are done at our facility under UL supervision. The costs for testing to a UL Standard is around $20,000 and if the CSA is required it is an additional $2,000. Whether you test to a standard or become listed or certified. You are also required to pay for quarterly internal audits on your processes to ensure that you are maintaining product reliability. The quarterly audits average $3,000 per year not including expenses.
UL1004-1 UL Standard for Safety Rotating Machines which assumes motor is not immersed in oil under normal use conditions. Assumes enclosure is metallic only and all critical components are individually recognized appropriately. The following test list is likely to apply; any additional tests found necessary during the construction evaluation will be performed under a change order: Rating Tests, Temperature, Mold Stress, Conduit hubs, Overcurrent, Hi-pot, Commutator Conditioning, Limited Short Circuit, Grounding & Locked Rotor.
UL1004-4 UL Standard for Electric Generators, assumes manufacturer does not wish to run the running heating test (optional) and product does not have intentionally weak traces. Assumes motor does not have automatic reset features for any thermal safety functions. Tests: locked rotor temperature test and locked rotor endurance test.
CSA Motors with Inherent Overheating. All testing to be performed concurrent or in place of UL 1004.