• Single motor protection with VFD per Article 430.130

    Looking for interpretation of Article 430.130(A)(1) and (2) with respect to Branch-Circuit Short-Circuit and Ground Fault Protective device rating for single motor applications when a VFD is installed. The article ref...
    last modified by tom.brenner
  • Emergency Egress Lighting

    Is there any code requirement to inspect path of egress light level on an annual basis?  With LED being used more often and known to fade over time, if there is not, shouldn't there be?  industrial hazards ...
  • ESD and Hazardous waste storage

    We have some 55 gal drums of flammable waste on site.  We keep them grounded with clamps to prevent static discharge.  Should we connect them through a resistor to slow the discharge and prevent sparking whe...
    created by stephen.mcdonald
  • Photovoltaic - 2017 NEC 705.12(B)(2)(3)(a) and 705.12(B)(2)(3)(b)

    The way I’m interpreting this section, the Photovoltaic installation must comply with either 705.12(D)(2)(3)(a) OR 705.12(D)(2)(3)(b):   (a) says that 125% of the inverter output circuit current (can be obt...
    last modified by chiefns830
  • Spray Rooms & Aerosols

    We have an issue with a man who built a homemade spray room in his tenant space of a shopping mall. It has no ventilation and he is blocking sprinkler heads with storage. The walls are covered with visqueen and the fl...
    last modified by ldesmares
  • Smoke detectors in multi-family building with fire alarm system

    Shall the smoke detectors in multi-family building ( individual units) to be connected to the building fire alarm system? if yes or no what's is the code section?
    last modified by kkhalifa
  • A burning question about removing leaves and other yard waste this fall

    For many, the fall months are a time for cleaning up our yards of accumulated leaves, sticks, and other vegetative debris before the long winter.  Disposing of this dried up green waste is becoming more difficult...
    last modified by faithberry
  • Egress Lighting with wireless RF switches

    Is there anything in the building codes prohibiting the use of wireless RF switches with egress lighting?  The wireless switches are powered with a button-type battery to turn on a tiny controller that ...
    last modified by chiefns830
  • Safety is at the center of NFPA’s Halloween-related materials

    Every year Halloween brings out excited children dressed in costumes running door to door to trick-or-treat as well as adults who dress up and head out to parties or make their own rounds through the neighborhood to a...
    last modified by lisabraxton
  • Minimun size for standpipes

    Good day, I need someone help me with the minimum size for a class II standpipe and branch lines. According to NFPA 14 7.6.1 class I and class III standpipe shall be at least 4 in. I have a class II design (by others)...
    created by maykol8850
  • Does PRV require by pass arrangement?

    Project location: Bangladesh Pump Capacity: 1500 GPM Pump Head: 14 bar. According to code for sprinkler pressure should not exceed 12 bar. So we need to use PRV upto certain height. If each PRV require to use by pa...
    last modified by istiaque.emcs
  • NFPA 410 - Electriicaly Grounded

    NFPA 410 section requires "To reduce the hazards associated with static electricity, aircraft shall be electrically grounded when parked in aircraft hangars."   Boeing Aircraft are statically ground...
    last modified by jeff.l.tjernagel
  • Elevator Recall

    Does Fire Sprinkler riser's water flow switch initiate elevator emergency recall? In NFPA 72 "Table A." Typical Input/Output Matrix" shows water flow switch on first or second floor initiate elevator emer...
    last modified by zara.mosavat
  • Are Sprinklers Required Above False Ceilings?

     Are sprinklers required above false ceilings? If required, What should be the Minimum Space above False Ceiling to consider sprinkler installation?
    last modified by hasparkar
  • NFPA terms (division/Zone)

    Hi,  In the NFPA 497 we speak about "division" and "zone". But, the area around figures still the same even if we speak about zones or divisions. Someone can tell what is the differences between this two terms ...
    last modified by ddufour
  • Kitchen Exhaust Ductwork Termination Through Roof

    NFPA 96-2011 (2) regarding roof top terminations states "roof top terminations shall be arranged or provided with the following... (2) a minimum of 1.5m (5ft) of horizontal clearance from the outlet to any com...
    last modified by jbraun
  • Hydraulic Calculation in big rooms having concealed Spaces (upright and pendent sprinklers)

    When doing the hydraulic calculations for an open space (having only upright sorinklers), we calculate the No. of sprinklers based on the Max. protection area and the Area of coverage (ex: 1,500 ft2 / 130 = 11.5 = 12 ...
    last modified by patrickbouchedid
  • DIGITAL inspection for annual fire extinguisher maintenance (seeking AHJ opinions)

    Hello,   We are looking at ways to make the annual maintenance process easier for more people, especially those in remote or rural areas who may have a hard time getting a service company to come and check their...
    last modified by mjpeters
  • MC cable for PV installation

    Article 330.12 prohibits MC cable when exposed to mechanical damage. 690.31(D) allows MC cable when intalled in an area that is not readily accessible.  My client wants to install MC cable across the open roof of...
    last modified by jeffrey

    - KITCHEN EXHAUST HOOD FIRE SUPPRESSION SYSTEMS - We get training from FPC- (Fire Protection Certification ltd.)  - Are there other companies that offer the same training? Thanks,
    last modified by frankterranova