Lighting & Lighting ControlsCommented on: 1 year ago (July 7, 2014)
The connected load is = to the input wattage from the ballast chart divided by the power factor. Assuming a 90% power factor, the connected load = 100 / 0.9 = 111.1 volt-amperes.
Lighting & Lighting ControlsCommented on: 1 year ago (June 25, 2014)
I’d like to make a few comments regarding the report published in the May 24 issue.
Two situations must be considered.: 1): the service is supplied in low voltage, or 2): the service is...
National Electrical Code (NEC)Commented on: 1 year ago (June 25, 2014)
Thank you for your observation. The strange thing is that the usual copy and paste procedure didn't work this time, since the previous 2011 and 2008 editions had the correct title for Table 220-44...
National Electrical Code (NEC)Commented on: 1 year ago (May 6, 2014)
I’m referring to NEC Annex D Example D5(b). The result shown for the Main Feeder neutral load (107,650VA) is copied from the result in Example D4(b). However, D4(b) is served at 120/240V (where...
Software & AppsCommented on: 1 year ago (March 11, 2014)
Electrical calculations for a project based on the many, many requirements of the NEC is not an easy task (for example: wire & conduit size, OCP, VD, derating factors, continuous /...
Actually, demand factors for electric welders is discussed in NEC, Article 630.
Great article, where the author explains the procedure of the calculations in a step-by-step fashion, referring each step to the applicable NEC rule.
I agree that this procedure is...
Isn’t there a method to do those tedious and time consuming NEC Annex D calculations via a computer program?
For other than dwellings, the calculated lighting load is the larger of the actual lighting load or the VA per sq ft from Table 220.12.
Thank you. A useful primer on Arc Flash.