Jay, Is the question when is a transfer switch required or when is alternate power required ?. A transfer switch will always be required when there is more than one source of power, there has to be a method of selecting one source of power over another.
Not sure what your adopted codes and standards stipulate, but with regards to existing buildings one often has to research where the alternate power source requirement came from in the first place and not necessarily current code requirements unless of course your jurisdiction has retroactivity provisions. Assuming there's not a prescriptive requirement (IBC/IFC/Local Amendment/Prior Approval) otherwise, one could make a case where a power source was deemed to be not reliable in the past and improvements made where the source is now reliable. For example, overhead service conductors that have been relocated underground. In any case here's the NEC language; NEC 695.1 Scope (A) Covered. This article covers the installation of the following: (1) Electric power sources and interconnecting circuits (2) Switching and control equipment dedicated to fire pump drivers (B) Not Covered. This article does not cover the following: (3) Transfer equipment upstream of the fire pump transfer switch(s) Informational Note: See NFPA 20-2013, Standard for the Installation of Stationary Pumps for Fire Protection, for further information. The requirements covering reliable power supplies for electric fire pump motors correlate with those in NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection. However, the NEC and NFPA 20 have a distinct division of responsibility for fire pump requirements. Performance issues, including the determination of power supply reliability, are under the jurisdiction of the NFPA Technical Committee on Fire Pumps, while electrical installation requirements are within the purview of the National Electrical Code Committee. The scope of Article 695 speaks to this division of responsibility. 695.3 Power Source(s) for Electric Motor-Driven Fire Pumps Electric motor-driven fire pumps shall have a reliable source of power. The determination of whether the serving electric utility is a reliable source of power is an issue for the AHJ. The following excerpt of A.9.3.2 in Annex A of NFPA 20 elaborates on several key characteristics of a reliable power supply: A.9.3.2 A reliable power source possesses the following characteristics: (1) The source power plant has not experienced any shutdowns longer than 4 continuous hours in the year prior (2) Power outages have not routinely been experienced in the area of the protected facility caused by failures in generation or transmission (3) The normal source of power is not supplied by overhead conductors outside the protected facility. (4) Only the disconnect switches and overcurrent protection devices permitted by 9.2.3 are installed in the normal source of power Hope this helps, John Drucker, CET Assistant Construction Official Fire Protection Subcode Official Building/Fire/Electrical Inspector Borough of Red Bank Red Bank, New Jersey Email: [email protected] Cell/Text: 732-904-6823 -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Jay Stough Sent: Thursday, March 19, 2015 7:54 AM To: Sprinkler Forum Subject: Pump transfer Switch When is a transfer switch required by the IBC or IFC? We have a customer that has a 7 story building with a fire pump (only 50 psi @ 750 with a street static of 52). It has a problem with the controller and parts are no longer available. We gave them a price to change out with a new controller, like for like, which includes a transfer switch. Now they want a price to replace without a transfer switch. I see that NFPA 20 (2007) 10.8.1 says to install a transfer switch if required by the AHJ or 9.3.2. 9.3.2 lays out the requirements for alternate power. I see that 9.3.1 says an alternate power is required when the height of the building is beyond the pumping requirements of the fire dept. Of course as part of the contract he wants us to get the approvals for removing the transfer switch. I am trying to see what I am up against in trying to remove this switch. *Jay Stough* NICET IV LAYOUT NICET III ITM _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
