UL and NFPA, what do they cover and when do I need them?
Here is a reference document that many of our customers have found useful. (PDF the secrets of UL and NFPA)
The enclosure I am looking to buy says UL, is that all I need to have a UL Certified Control Panel?
The UL Certified label on the enclosure is just for the enclosure. For a UL Certified Control Panel, you need a UL Certified Panel Shop to verify compliance, build, and certify. See this link for a useful article related to UL Certifications. (Dark secret about certified control panels)
PNP & NPN, which is which and when should I use one vs the other?
Here is an excellent article that breaks down and answers this question well. (How to decide between PNP and NPN)
