I have 3 500 THHN .7073 sq. in area and I choose a 2" EMT AS THE RACEWAW WITH 2.013 Sq. in. area, and I use chapter 9 note 4 that allows me to fill the conduit to 60%, am I correct? because this looks like it's too small, but I'm doing practice quizzes on line and the person is saying 2" EMT IS THE CORRECT SELCTION?
in Electrical
Is there a requirement for a minimum distance between a buried 33 000 KV line and a natural gas line? If so what is this minimum distance? Where can further information be found on this subject? Thank you.
in Electrical
Hello all,    We recently had to upgrade all of our products to run with Design B energy-efficient motors. After a few weeks we started getting customer complaints of nuisance tripping. After investigating we discovered the new motors have much higher inrush ratings.    For example: Motor FLA was 13.1, with inrush spikes up to 194 A. Our thermal… (Show more)
in Electrical
Click to view contentAll Retail Shops are recommended to be provided with Quick Response Sprinklers. Fire Size used in the calculations is 2.5 MW considering Quick Response Sprinklers in compliance with BS 7346 Part 4 Table 3.     NFPA – 13, where listed quick-response sprinklers, including extended coverage quick-response sprinklers, are used… (Show more)
in Building & Life Safety
If I have a hypothetical 480/277V, 3 Phase, 4 wire feed to a distribution panel. (Spare panel for future use, we do not know the load) Do you de-rate because it is 4 wire? Following 310.15(B)(5)(c) If the majority is non-linear (meaning greater than 50%?) we would de-rate because of 4 wire. (Correct?) Or does this apply only to a branch circuit,… (Show more)
in Electrical
I am interested in finding the code for allowing/omitting fire hose reel connection in an electrical room containing LV switch gear. I know from an engineering prescriptive that it is not allowed/recommended but cannot find an NFPA standard reference as I am new to the construction field.
in Fire Protection Systems
Hi All,   I am making a 3 Phase power meter using a MICROCHIP IC ATM90E36A. They recommend to use neutral wire as a GND reference to measure voltages at 3 hot legs but in my loads (Air Conditioners) there is no neutral wire. We will only have an earth ground.    According to your expertise : is it safe to use GND earth instead of neutral for the… (Show more)
in Electrical
Air supply piping from and air compressor. I see that some air compressors are connected with stainless steel braided hose. Does this hose have to be listed for fire protection use? I can’t seem to locate any relevant information in NFPA 13. 
in Fire Protection Systems
Hi, I'm working on a hangar project which is a Membrane-Covered Rigid-Steel-Frame-Structure Hangar. The hangar has a 6800 m2 fire area. With regard to fire protection system design as per NFPA 409-Chapter 9, I'll proceed with high-expansion foam system as specified in states the following "The application total discharge… (Show more)
in Fire Protection Systems
Hi, the topic is fire sprinkler system in a big aquapark. What about internal swimming pool with many plastic slides. I think above swimming pool sprinklers are needed to protect construction of building. What about density in this area? I cant imagine sprinkler under slides, there will be obstruction. What about it?   Best regards Joanna… (Show more)
in Fire Protection Systems
The criteria I know are as follows   According to NFPA.13 chapter 17, ESFR protection provided with in rack sprinkler. Maximum ceiling/roof height is 45ft.   =============================================================================  Do you have the following criteria?   "no limits on building height with in-rack sprinklers."   Thank you… (Show more)
in Fire Protection Systems
In Laser Tag Arenas, there are team Bases. Each project has different themes and therefore have different designs for Bases. Most Bases have an overhead element connected to 2-4 walls.   Question: What specific rules would these structures need to follow, in-order to NOT need a sprinkler under / inside the structure?
in Fire Protection Systems
Does this building require a suppression system?    Conditions:       Existing motel built in the late 1960s    Abandoned (4-6 years)      Under remodel (new drywall, plumbing, electrical, mechanical)     60 units    12,000 sq foot building      Fire resistive (cement block) construction     Two stories     Rooms exit to the parking lot… (Show more)
in Fire Protection Systems
Load more items