NPSTC congratulates the Telecommunications Industry Association (TIA) on the American National Standards Institute approval of their new standard. The TIA standard answers public safety’s need for technical information related to the design, manufacturing, and testing of battery-powered, Land Mobile Radio (LMR) equipment, typically either hand-carried or worn on the person. These radios are designed and manufactured to be incapable of being a source of ignition in Division 1 Hazardous (Classified) locations as defined in Article 500 of the National Electric Code (NEC) NFPA – 70. This standard relies heavily upon a contribution from Underwriters Laboratories, Inc.
Background: In September 2010, NPSTC learned a new version of the intrinsically safe standard affecting Land Mobile Radio (LMR) was to go into effect January 1, 2012. The standards for intrinsically safe electrical equipment apply to equipment used in hazardous locations, including LMR. A standards certification organization, FM Approvals announced their intention to replace their current, still safe standard, FM 3610:1988, with the new FM 3610:2010.
The energy constraints imposed by meeting the new FM standard would have resulted in limiting the transmit power capabilities of LMR products. The actual power reduction could vary by manufacturer because different design considerations are employed. But there is no question that power would be reduced if traditional product size, weight, and duty cycle requirements were retained. The impact of the changes would have affected more than basic product design of portable radio equipment. Significant system infrastructure expansion might have been necessary to maintain current geographic and in-building coverage.
In response to this serious issue, NPSTC’s Intrinsically Safe Working Group issued a position paper, initiated discussion with FM Approvals, and participated in meetings with the International Society of Automation (ISA). NPSTC met with the Telecommunications Industry Association (TIA), Occupational Safety & Health Administration (OSHA), Land Mobile Communications Council (LMCC), and many public safety groups to discuss this issue. In late 2011, TIA convened an Engineering Subcommittee to create a new LMR-specific standard for intrinsic safety. That new TIA standard released this month provides the same protection for the same power levels as the older FM standard. This is good news for public safety telecommunicators.