If the power source is a listed Class 2 transformer or listed Class 2 power supply — or it’s in listed equipment marked to identify the Class 2 power source — you’ve got a Class 2 circuit between the ...

Article 725 provides the requirements for Class 2 circuits in Part III. The definitions for Class 2 circuits can be found in Art. 100. In the November 2020 issue, we discussed the general requirements ...

I see techs in the field get the most frustrated when they have a low-voltage short they can’t seem to locate. The challenge techs face with low voltage diagnosis is a combination of poor process and ...

Bob and Tim are discussing the job that they are about to start. They are at a residence and the system has a blown low-voltage fuse. Tim said, “Let’s just change the fuse and try it and see if the ...

The models 15951 and 15952 UL-listed Class 2 control transformers suit a variety of industrial control systems, including radio and audio. The 15951 is rated to 15 VA, and the 15952 is rated 30 VA and ...