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Joe Nelson
NEC 2017 680.26(B) states that conductive pool shells shall be bonded. 680.26(B)(1) states that, "Vinyl liners...shall be considered to be nonconductive materials." Some pool construction methods that utilize nonconductive vinyl liners also utilize a (unreinforced) concrete base (or shell) between native soil and the vinyl liner material. … (Show more)
in Electrical
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ahmed elgazar
moke system activation, signal to  activte  smoke system  cab sent from  smoke detector  of  water flow  switch  in  sprinkler system  i ask  about  case that recommended used onley water flow switch  instead of  detectors.
in Fire Protection Systems
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Akhil Anand
i would like to know the minimum diameter of pipping allowed for sprinkler system if it is made up of galvanized steel or iron ?
in Fire Protection Systems
tine dolinsek
Our design is dealing with sprinkler protection for rack storage of cartoned group A plastics. Due to a height of over 25 ft (7,6m) the arrangement drawn in Figure 17.3.1.5 (b) has been chosen for single and double row racks. What is the maximum  vertical distance between in-rack sprinklers for this arrangement? My question is: Is it 10ft (3,0m)… (Show more)
in Fire Protection Systems
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Jennifer Hildebrand
I was recently at a residence where they had two separate and distinct switch boxes stacked on top of each other.  The upper switch box was recently put in by another electrician and the lower switch box has been in use for a few years.  Does this stacking of switches (One on top of the other spaced by approximately 1.5 inches) violate the NEC?… (Show more)
in Electrical
Gregory Mercer
I am trying to determine whether or not there are any retention period requirements for the Infrared Inspections. I found under 11.17.5 of 70B the Infrared Information, but it does not mention best practice on how long to store records from the testing. Is there a time period to keep these records?     Thanks again, Tyler
in Electrical
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Steven Dube
Has anyone come across this in a fire investigation:   LONDONDERRY — Officials say a refrigerator is the likely source of a two-alarm garage fire Tuesday evening in Londonderry.   Crews arrived around 5:36 p.m. at 19 Chandler Drive to find a fully involved structure fire in a standalone garage, but the flames had not yet reached the main… (Show more)
in Emergency Response
Jason Tomsett
For one-off/custom built pieces of manufacturing equipment that can be simply unplugged before servicing, is it still necessary to have a lockable power switch? My local AHJ says that as long as the switch is within sight of where the servicing is being done then it's OK to not have a lockable switch.  However much of the equipment gets shipped to… (Show more)
in Electrical
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Fred Durso
Have you listened to our five-part podcast series, "The Survivors"? It humanizes NFPA's statistics on home fires by underscoring the ordeal and aftermath of one family after they lost two children to home fire.    Please reply to this blog and let us know if you've listened to all or any of the episodes. Were you moved by the family's story? Did… (Show more)
in Public Education
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Jesus M Carrasquillo
I am very aware that NFPA 25 inspections reference and are in relation to NFPA 72 standards. The question is: Is it require to verify the proper activation of notification appliances during a routine NFPA 25 inspection granted the building is equip with a full functional fire alarm system. If so, disabling such during the inspection can be… (Show more)
Jonathan Wong
A wonderful discussion with my friend michael.civitello inspired this conversation.   Michael pointed out that moderate sedation is permitted in both NFPA 99 2015 and 2018 Category 2 and 3 medical gas systems.  Meanwhile, in the new Chapter 15 Dental Gas and Vacuum Systems of NFPA 99 2018, Category 3 systems allow only minimal sedation and… (Show more)
in Building & Life Safety
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