As the government strives to implement healthcare reform and is approaching many hurdles, the 2011 National Electrical Code (NEC) is well into the development process. Technical committees have acted upon all NEC change proposals and comments. This month, the National Fire Protection Association (NFPA) will host its annual conference and exposition where the final NEC technical session will take place. At this meeting, the membership is afforded one last opportunity to shape the Code for the coming cycle, as final revisions can happen by floor actions.
Part VI of Article 517 provides rules for communications, signaling systems, data systems, fire alarm systems and systems operating at less than 120 volts. The requirements in this part of Article 517 are in addition to other applicable rules in Chapters 7 and 8 that apply generally to all healthcare occupancies. Section 517.80 of the NEC indicates that equivalent insulation and isolation to that required for the electrical distribution system in patient care areas shall be provided for communications, signaling systems, data system circuits and fire alarm systems in healthcare facilities. This section also provides clarification for users that raceways, such as rigid-metal conduit or electrical-metallic tubing, are not required unless it is specifically called for in either Chapter 7 or 8. A new second sentence has been added to this section that clarifies that Class 2 and Class 3 signaling and communications systems and power-limited fire alarm systems are not required to comply with the redundant grounding requirements of 517.13 because these are not branch circuits by definition. Even though these systems often are connected to the essential system, they are not required to comply with the mechanical protection requirements of 517.30(C)(3) or (C)(5). Former Section 517.30(C)(5) has been renumbered as (C)(6) to allow for a new list item (2) that recognizes listed MC cable as providing equivalent mechanical protection for the essential electrical system. This revision in 517.30(C)(6) now provides a definitive correlation between this rule for essential systems and Part VI covering low-voltage and limited-energy systems. Section 517.80 has been revised to clarify that Class 2 and Class 3 signaling and communications systems and power-limited fire alarm systems do not have to comply with the grounding requirements of 517.13, to comply with the mechanical protection requirements of 517.30(C)(3)(6), or to be enclosed in raceways, unless otherwise specified by Chapter 7 or 8. This change should reduce the misapplication of this section by enforcement officials and other users and allow this installation exemption for limited-energy systems as intended.
Power-limited fire alarm systems also are included based on the power limitations of such circuits and the reduction of shock hazards. The revision to this section also correlates with similar changes in Section 517.30(C)(6) that recognize these systems being installed with or without raceways as a means of physical protection whether part of an emergency system or not. Obviously, where these systems are subject to physical damage and the need for physical protection is predicated, it should be provided as a general requirement. A nurse call system is an example of a limited-energy system that would fall under the requirements in Section 517.80. An acceptable alternate means of providing isolation for patient/nurse call systems is by the use of nonelectrified signaling, communications or control devices held by the patient or within reach of the patient.
Although the NEC relaxes the requirements for installing metal raceways for communications systems, signaling systems, and other limited-energy circuit wiring, these systems must always be installed in accordance with the job plans and specifications. An interesting dynamic is taking place between NFPA 99 and NFPA 70. It should be understood that although performance requirements should drive installation requirements, they should not be trumped by important safety requirements that have been determined through the NFPA and ANSI consensus process. Often an owner and design team have already determined the desired level of quality for the electrical wiring system. So although the Article 517 of the Code generally calls for more restrictive wiring than Chapters 1 through 4, these requirements are still the minimum. Always verify with the designing professional for the project if there is any doubt about what the plans and specifications require for installation of these systems.
JOHNSTON is NECA’s executive director of standards and safety. He is former director of education, codes and standards for IAEI; a member of the IBEW; and an active member of the NFPA Electrical Section, Education Section and the UL Electrical Council. Reach him at firstname.lastname@example.org.