ARCHIVED REPORTS LEC APPLICATION FOR CERTIFICATION

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SECTION 3.0:ELECTRIC TRANSMISSION The electric field gradient is greatest at the surface of the conductor. Large-diameter conductors have lower electric field gradients at the conductor surface and,hence,lower corona than smaller conductors,everything else being equal. Also,irregularities (such as nicks and scrapes on the conductor surface) or sharp edges on suspension hardware concentrate the electric field at these locations and, thus,increase corona at these spots. Similarly,contamination on the conductor surface, such as dust or insects,can cause irregularities that are a source for corona. Raindrops, snow,fog, and condensation are also sources of irregularities. 3.4.2.3 EMF,Audible Noise, and Radio and Television Interference Assumptions It is important to remember that EMF,audible noise, and radio and television interference near power lines vary with regard to the line design,line loading, distance from the line, and other factors. Electric fields,corona, audible noise,and radio and television interference depend on line voltage and not the level of power flow. Because line voltage remains nearly constant for a transmission line during normal operation,the audible noise emanating from the 230-kV lines in the area will be of the same magnitude from the incoming transmission line and the outgoing transmission line from the LEC. Corona typically becomes a design concern for transmission lines having voltages of 345-kV and above. Since the LEC will be connected at 230-kV voltage level,it is expected that no corona-related design issues will be encountered. The magnetic field is proportional to line loading(amperes),which varies as demand for electrical power varies and as generation from the generating facility is changed by the system operators to meet changes in demand. The construction and operation of the LEC,including the interconnection of the LEC with PG&E's transmission system, are not expected to result in significant increases in EMF levels,corona,audible noise, or radio and television interference. 3.4.2.4 Induced Current and Voltages A conducting object such as a vehicle or person in an electric field will experience induced voltages and currents. The strength of the induced current will depend on the electric field strength,the size and shape of the conducting object,and the object-to-ground resistance. When a conducting object is isolated from the ground and a grounded person touches the object,a perceptible current or shock may occur as the current flows to ground. The mitigation for hazardous and nuisance shocks is to ensure that metallic objects on or near the right-of-way are grounded and that sufficient clearances are provided at roadways and parking lots to keep electric fields at these locations low enough to prevent vehicle short- circuit currents from exceeding 5 milliamperes. Magnetic fields can also induce voltages and currents in conducting objects. Typically,this requires a long metallic object, such as a wire fence or aboveground pipeline that is grounded at only one location. A person who closes an electrical loop by grounding the object at a different location will experience a shock similar to that described above for an ungrounded object. Mitigation for this problem is to ensure multiple grounds on fences or pipelines,especially those orientated parallel to the transmission line. 3-8 SAC/371322/082350006(LEC_3.0_ELECTRANS.DOC)