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?
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
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.
I understand that NFPA 24 does not include ASTM 53 steel pipe to be used underground for firewater main piping for a private fire protection service (Table 10.1.1.1) but does allow via referenced to NFPA 13 for above ground piping (Table 18.104.22.168) to be of ASTM 53. What is the reasoning behind not allowing ASTM 53 steel pipe, even cathodically… Show more
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.
I know that for utilities, there is a minimum radial separation distance. But there isn't anything like that in NEC. Maybe a gas person can chime in and let us know about their code. This next go-round in the NEC, I may try for radial separation distance in the same trench. The code panel might approve that.
All 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, 22.214.171.124.3.1 where listed quick-response sprinklers, including extended coverage quick-response sprinklers, are used… Show more
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.