UL Question Corner: Low Voltage LED Luminaire Drivers

Q. I have encountered Listed low voltage LED luminaires shipped without a driver. Do I have to use a power supply/driver...

UL Question Corner: Field modifications of UL Certified (Listed) products, tapping...

Q. When a UL Certified (Listed) product leaves the factory, the UL Mark on the product...

UL Question Corner: Leakage current

Q. I know cord and plug-connected appliances are tested for leakage current but are hard-wired appliances...

Horticultural grow lights and plant oil processing

Q. Recent legislative changes in my state have resulted in many indoor horticultural grow operations. Does...

Certification requirements for line side connectors

Q. Do wire connectors used to make line side splices or taps need to have a...

UL Question Corner: Certification requirements for line side connectors

Do wire connectors used to make line side splices or taps need to have a short circuit current rating (SCCR)? If I use a...

UL Question Corner: Installing power monitoring equipment in panelboards

NEC-2017 Section 312.8(B) was added to allow installation of Listed power monitoring equipment inside panelboards. Where can I find power monitoring equipment that is...

UL Question Corner: System combination AFCI’s

 Are there any Certified (Listed) system-combination arc-fault circuit interrupters (AFCIs) for use in accordance with NEC 210.12(A)(4)? How are they identified? Yes. UL does Certify...

Three Phase to Three Phase VFDs in a Single Phase to...

I find inspecting the wiring and branch circuit protection of a three phase to three phase VFD used in a single phase to three...

Pool Lifts and PV Connectors

Question I see in the 2017 NEC Section 680.81 requires electrically powered pool lifts to be Listed.  Does UL Certify (List) these types of pool...