2017 National Electrical Code
Conduit and Cables Exposed to Sunlight on Rooftops
Anyone who has been on top of a roof on a hot summer day knows what it’s like to stand in the middle of an oven. Extreme temperatures from the sun can bake everything in sight, from shingles to appliances, and even electrical conductors and conduit.
Conductor insulation is meant to provide long lasting protection from expected heat due to the flow of electricity and normal environmental factors. However, excessive heat from solar radiation can damage conductors and cause premature failures.
Field Labeled & Field Evaluation Body (FEB)
Two new terms found in Article 100, and a clarified evaluation-practice established for the 2017 NEC code-cycle
Electrical equipment is generally approved by a testing laboratory before being shipped by a manufacturer. However, sometimes electricians may need to install spe-cialized gear that has not yet been formally certified. When field certification is neces-sary due to a lack of a UL (or other approved laboratory) Listing, electricians are then required to contact a Field Evaluation Body (FEB) to receive an approval label. Fortunately, updates and new terms in the 2017 NFPA 70 National Electrical Code (NEC) help clarify what should be done when items need to be field labeled by a Field Evaluation Body (FEB).
NEC 210.52(C)(3) New Peninsular Receptacle Requirements for the 2017 NEC
The method for measuring the countertop space for peninsulas has been changed for 2017. We know that NEC Section 210.52 requires that at least one receptacle be provided for each island or peninsula countertop that fits the dimensional requirements. The intent of the Code here is to discourage the use of extension cords. For example, countertop outlets must be spaced so that the typical two-foot extension cord can reach an outlet from any part of the countertop. Previously, the minimum distance triggering the outlet requirement was measured from the junction where the peninsula abutted the front edge of the perpendicular countertop, thus usually requiring an outlet mounted in the peninsular base cabinet. The new method of measurement begins at the wall behind the countertop.
How To Apply Ohm’s Law
Electricity operates within predictable boundaries. We have come to identify these boundaries as Ohm’s Law. Ohm’s Law was developed as a means of explaining how electricity operates within a closed circuit. The Ohm’s Law formula helps to communicate the relationship between different properties within an electrical circuit. We can use Ohm’s Law to explain what has occurred, as well as what will occur, when certain conditions are imposed upon an electrical circuit.