110.24 revisited This is one for the top ten changes to the NEC

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In sections 110.24 (A)(B) the Code has made it your job to verify the available fault current at the service.  You will need to field mark the equipment with the fault current that is available at your service and with the date the calculation was performed.  These markings need to be legible and able to withstand the environmental conditions of our South Florida climate; sunlight and water resistant.

The available fault current will be calculated on the basis of a number of contributing factors like the size of the utility transformer and the location of the transformer in proximity to your service.  The type, length, and size of conductors used in your service will also figure into the available fault current.  Not marking your service will delay receiving a final inspection from your local inspector or issuance of your permit from your plans examiner. The 2011 Code goes into effect on July 1st .  All plans and permits received after this date will be governed by these new changes. I am bringing these changes to your attention so it wont be a surprise when the AHJ asks.

When you sit down to figure the price for that next service change or modification, remember that in order to perform these calculations you will need information that is not readily available to you. You will need to contact the utility for some of this information.  This will cost you time; and we all know time costs you money.

 

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