• Is it simple to change electrical receptacle?

    Don't assume that even the most "simple" electrical jobs aren't dangerous:   http://archive.tcpalm.com/news/sebastian-handyman-charged-with-not-having-a-license-after-employee-dies-ep-396486835-347245332.html/
    last modified by chiefns830
  • TEST

    last modified by chiefns830
  • Lifepo4 safety

    I live off the grid and in need of new battery's for my solar system. After a long study I believe a Lifepo4 system would be the best alternative for my needs. Lifepo4 has a safety factor that is so much better than a...
    last modified by scberd
  • Cell tower cable running up have equipment grounding conductor

    I have monopole cell tower. The tower has DC conductor cables that run from equipment on ground to cell tower antennas, RRUs, etc up top. Kind of like this: or like this in web link below:   https://wireless...
    last modified by apurvadave
  • NEC information about motors

    I have had a 300hp motor shipped to me with the motor opening being to small for the amout of leads that are coming out. So small infact that the motor leads insulation was being cut by the conduit adapter on the moto...
    last modified by cclabbers
  • EXCP (EXtraneous Conductive Parts) and ECP (Exposed Conductive Parts) bonding requirements per NFPA79 and NFPA70

    Hello,   I have a question in regard to NFPA70 article 250 and NFPA79 8.2.1 with EXCP and ECP. If a machine, ECP, has a part that can not be energized but is considered an EXCP per NFPA79 definition; does the EX...
    created by stephen.hafner
  • Maximum spacing of 8' mid-roof air terminals

    Can 8' midroof air terminals be spaced more than 50' apart?
    created by otorres
  • NEC 2014 grouping

    Assume that two SWGRs A and B are in compliance with NEC 2014 Section 230.2 first paragraph which says:   For the purpose of 230.40 Exception no. 2 only, underground sets of conductors, 1/0 AWG and larger, runni...
    last modified by apurvadave
  • NEC 2014 Section 230.40 exception no. 1

    Attached sketch shows building layout bottom left corner, electrical room detail bottom right corner and Riser at top.   Building layout shows Vacant space which has not been filled and Tenant A space occupancy ...
    created by apurvadave
  • Trough busbar bonding methodology

    I have metallic trough load side of service disconnect means whose enclosure needs to be connected to the equipment grounding conductor. The trough has equipment grounding bus bar inside it.   In attached Figure...
    last modified by apurvadave
  • Two services multi occupancy building

    Attached sketch shows utility xfmr1 200A 480/277V existing which feeds the existing fdr #1 electrical room in multi occupancy bldg. The plans now show new xfmr2 800A 480/277V which feeds thru new fdr #2 Electrical R...
    last modified by apurvadave
  • Luminaire Weight

    Hello,   What is the maximum weight allowed for a luminaire that is supported by an electrical cord?   For luminaires supported by the screw shell of a lampholder, NEC 410.30 says it can't exceed 3kg or 40...
    last modified by byronc
  • Conduit for battery cables

    I'm trying to get a definitive answer about if a 48V battery bank has to have its cables in conduit. 2014 NEC 690.71(B)(2) said "Live parts of battery systems for dwellings shall be guarded to prevent accidental conta...
    last modified by rosewood
  • 230/400V Color code

    Hi, my name is Andres, I m a student in electromechanical engineering, I have a doubt about the color code in voltage system, I know that 120/208/240V is: phase A= black, phase B=red, phase C= blue and nuetral=white, ...
    last modified by andrescr54
  • Fire rate cables for LPG leak detection

    I would like to know in which NFPA that requires the cables used in the LPG detection system shall be fire rated cables? is it NFPA 54 or 70? which section exactly, please?
    last modified by eng_mikemo
  • Neutral to earth voltage is high.

    We are facing a peculier problem of Neutral to Earth voltage high.   2MVA Transformer 11KV/0.433KV , Dry type transformer is installed with LT drives.   When Drives are running in Regenerative Mode Neutral...
    last modified by vannamani.a
  • Main Bonding Jumper Location and Main service Disconnect Residential

    Hey guys,  I'm doing a 3600 sq ft residential job where there is 1800 up and almost 1800 finished basement. The homeowner wants the panel located in the utility room in the basement which is 35' (cable length) aw...
    last modified by jeff_schirmer
  • Transformer Secondary conductor - Overcurrent Protection

    Requirement (2) Transformer Secondary Conductors Not over 3m (10 ft) Long and Requirement (3)Industrial Installation Secondary Conductors Not Over 7.5 m (25ft) Long. We have fulfilled the sub-clauses but which require...
    last modified by cl_yeoh
  • Is it advisable to dress or clamping in ( LT 415V) charged cable?

    LT 15V Cables are already laid and charged in Ladder type cable trays. Is it advisable to dress or clamp the cables in charged condition? Will it be safe? What precaution is to be taken?
    last modified by vannamani.a

    Can pvc coated Mc cable  be used under pavers on a terrace In nyc
    last modified by mungret