Low Voltage Wiring

Q: We recently underwent a mock survey in preparation for a full survey soon. The Life Safety mock surveyor cited us for failure to cover low voltage junction boxes. We had differing opinions about the requirement. A member of our team feels that the NEC requirements do not apply in Montana. I was not able to verify that statement. My question is twofold: 1. What experience & opinion do you have about the treatment of low voltage under the same code as high voltage? 2. Are you aware of state (or other codes) which are less stringent taking precedence over more stringent codes?

A: You can never take a less stringent code or standard, over a more stringent code or standard. You always have to comply with the most restrictive requirement. And yes, the National Electrical Code (NEC) NFPA 70-2011 does apply at your facility, regardless if your state requires it or not. This is because you are required to comply with the 2012 Life Safety Code and sections 18.5.1 and 9.1.2 require that you to comply with NFPA 70-2011.

In regards to low-voltage electrical wiring NFPA 70-2011 has many different Articles, depending on the application. Article 300.2 (A) says the requirements in chapter 3 apply to all voltages 600 volts or less. Article 411 is a standard on low-voltage lighting systems operating on 30 volts or less. But Article 517.80 is the one that you will be interested in: It says in healthcare patient care areas, low voltage wiring for communication systems and fire alarm systems less than 120 nominal volts, have to have an equivalent level of insulation and isolation to that required for electrical distribution systems in patient care areas, but the Class 2 and Class 3 signaling and communication systems do not have to comply with the grounding requirements or with the mechanical protection requirements, including raceways.

So, according to the NEC, you are not required to cover low voltage wiring junction boxes… But I advise that you do. Most surveyors will not know be able to tell low voltage qualifying under Article 517.80 when they see it, and will likely cite you for non-compliance.