The main flow switch, while I don't think is reqd, provides redundancy AND can monitor for someone opening a hose valve on a standpipe. If there's no pump, there'd be no pump run signal, and could have a lot of flow without alarm. We install them routinely as protection from vandalism and the redundancy confidence increase gained with "backup" master flow switch.
George Church' Rowe Sprinkler [email protected] 570-837-7647 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of David de Vries Sent: Friday, December 10, 2010 12:16 AM To: [email protected] Subject: RE: "main" flow switch On this issue of alarm system zoning, it is important to look at the Annex of 72, which has text applicable to sprinkler systems: A.4.4.6.6 (5) If a floor area exceeds 22,500 sq ft, additional zoning should be provided. The length of any zone should not exceed 300 ft in any direction. If the building is provided with automatic sprinklers throughout, the area of the alarm zone should be permitted to coincide with the allowable area of the sprinkler zone. I would have to dig, but I think other editions of 72 had the sprinkler zone exception in the main body of the text. Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated --- On Thu, 12/9/10, John Drucker <[email protected]> wrote: From: John Drucker <[email protected]> Subject: RE: "main" flow switch To: [email protected], [email protected] Date: Thursday, December 9, 2010, 10:02 PM 2007 NFPA-72 4.4.6.6.1 For the purpose of alarm annunciation, each floor of the building shall be considered as a separate zone. If a floor is subdivided by fire or smoke barriers and the fire plan for the protected premises allows relocation of occupants from the zone of origin to another zone on the same floor, each zone on the floor shall be annunciated separately for purposes of alarm location. John Drucker, CET Fire Protection Subcode Official Fire/Building/Electrical Inspector Fire Marshals Office Borough of Red Bank, NJ Not the official position of any agency, association, committee or otherwise. Verify all applications and approvals with your local authority having jurisdiction. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Chris Cahill Sent: Thursday, December 09, 2010 9:13 PM To: [email protected] Subject: Re: "main" flow switch Consider the FF's if you do one. Try to set the retard the shortest so it's not on the panel when the FF's arrive. If they see the zone actually causing the alarm it will get the water mitigation started faster. Chris -----Original Message----- From: David de Vries <[email protected]> Sender: [email protected] Date: Thu, 9 Dec 2010 17:06:27 To: <[email protected]> Reply-To: [email protected] Subject: Re: "main" flow switch Ed: Unless a high-rise, 13 only requires a single flow switch for an entire building. I am not aware of a "main" flow switch as a code requirement, but as an engineer I have often spec'd one, typically in the pump room downstream of the pump, where there are multiple systems, or floors, supplied through a feed main. Flow switches have been known to fail and having redundancy provides a level of comfort, especially if there is a long run of feed main. I do know that the pump controller is wired for supervision, but if the building is monitored by an alarm service, that signal comes in as a supervisory, not an alarm that rolls the trucks. Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated --- On Thu, 12/9/10, Ed Kramer <[email protected]> wrote: From: Ed Kramer <[email protected]> Subject: "main" flow switch To: [email protected] Date: Thursday, December 9, 2010, 4:52 PM Apologies if this has been discussed previously. Is anyone aware of a code requirement for a "main" flow switch? This would only occur in a building with multiple systems (such as 1 wet and 1 dry, or 3 wet, etc). The "main" flow switch would be located upstream of the individual system risers and would be in addition to the flow switches/pressure switches on the wet/dry systems. I've seen a number of projects where they are called for, but am curious if it's a code requirement or not. Ed Kramer Littleton, CO _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
