UL Question Corner: Luminaires & Energy Codes

Question. Energy codes require that residential recessed cans be tested for air leakage. If I have a Listed recessed can that is also marked...

Consequences of Harmonizing Low Voltage (600, 1000 and 2000 V) Ratings...

Abstract National electrical codes provide the necessary recognition for products and stipulate the installation requirements for their applications to ensure safety of personnel and property....

How electricians test continuity of protective conductors

For all protective conductors, including main and supplementary bonding conductors, electricians must perform a continuity test using a low-reading ohmmeter. For main equipotential bonding,...

UL Question Corner: Are there “UL Authorized” Service People?

Are there “UL Authorized Service People” who can modify UL Listed equipment in the field with no need of a UL field inspection or...

UL Question Corner: Generator Enclosures

I have a typical UL 2200 Listed generator installation set on a concrete pad. The generator has an overall enclosure, and inside that enclosure...

Medical Grade Strip Requirements, an Overview

Due to the many safety standards that apply to medical grade power strips, identifying the correct set of standards for a patient care application...

Ask the UL 3DP Expert

I am ready to buy a 3D printer for my home or company. Do I need to be concerned about personal safety while operating...

UL Question Corner: New Understanding HazLoc App

I rarely deal with hazardous location installations and find it difficult to grasp the concepts each time I have to inspect one.  Does UL...

Field Evaluations: An Inspector’s Point of View

I remember 20 plus years ago working as an electrician at several Boeing facilities in Seattle Washington, and having the State Inspector at the...

An Approved Degree of Detail

I  AM FORTUNATE that I work for an AHJ that allows me to express myself so freely. I can write just about whatever I...