IEEE 1827-2016 pdf download

IEEE 1827-2016 pdf download.IEEE Guide for Electrical and Control Design of Hydroelectric Water Conveyance Facilities
4.2 Environmental considerations
Operation of water conveyance facilities often poses signifcant risks to the environment. For this reason, environmental protection should be taken into consideration during every stage of water conveyance facility design. Owners and designers are obliged to mitigate environmental risks to required levels. Specifc systems may be required to achieve environmental objectives (e.g., a fsh diversion system to divert fsh away from a power intake).
Such systems typically require power, sensors, controls, alarms, and asso- ciated cables. In some cases, communication systems and automatic actuators are required. Redundancy or back-up should be considered depending on the level of risk (see 8.1, 8.2, 8.3, and 8.4 for guidelines and recommendations). A detailed discussion of environmental requirements is beyond the scope of this guide. See the following for further guidance:
— Government regulations
— Corporate policies and requirements
— Operating or water use permit or license, or other environmental commitments
— Operating environment
Devices and instruments used should be capable of operating under all expected environmental conditions. In- stallation should also include any protective shrouds to reduce damage from snow, ice, brush, or other debris.
Field device specifcations should include heavy duty and oil tight characteristics, corrosion ratings, quantity, rating, type of contacts, NEMA 4X or 6P rating, UL listing, operator lever type, type of material (e.g., steel, stainless steel), operating temperature range, copper or fber optic leads, side or top mount, standard and ex- tended operating ranges, installation instructions, and surge protection. Much of the electrical supply system may be located outdoors and exposed to harsh environmental conditions.
The following should be considered during the design and installation:
a) Extreme high water, food conditions: Power cables should be protected from fooding for the worst water conditions or designed for underwater service. The efects of seiche should be included. Under- water cable entrance and egress points should be designed for the maximum high level/fow condi- tions. Panels, junction boxes, and cables should be designed with the appropriate NEMA 250 [B21] or IEC 60529 [B12] weather rating, oriented to prevent fooding, and equipped with passive drains to remove excess water.
b) Extreme cold: Friction may increase with low temperatures, increasing loads on motors to the point where they may trip on overload or stall. Motors may need to be sized or specifc torque curves used to meet load demands with adequate safety margins. Equipment, oils, greases, etc., should be evaluated for reliable operation in the coldest conditions to be encountered. Some electronic equipment becomes unreliable or inoperable at low temperatures or can be susceptible to condensation and may require local heaters. Heat sources should be on reliable power supplies. Continuous monitoring of electrical circuits is recommended (e.g., current monitoring). Redundant power sources should be considered. Heaters for buildings, gates, gate guides, gearboxes, and other items should be considered. For further details see the Guidelines for Inspection and Evaluation, 2012.
c) Electrical storms: Lightning can disrupt power and cause surges to remote equipment. Surge protec- tion and proven grounding practices should be used to reduce damage. Lightning can disrupt power and communications to remote equipment. Lightning may cause safety issues for personnel. Equip- ment grounding should include appropriate measures for personnel protection. Step and touch po- tentials should be considered for operation of this equipment where lightning may occur. Lightning may also cause elevated local ground potential afecting electronic equipment. To protect equipment, design engineers can install direct stroke lightning shielding. Refer to IEEE Std 998. Surge protection devices and common mode voltage immunity may be required. Refer to IEEE Std 80, IEEE Std 1050, and IEEE Std 1692 for further information. Refer to NFPA 780 for installation of lighting protection systems.
d) Snow and ice: Snow and ice loading should be considered in the design of any mounting, structures, cabinets, cable routing, surfaces, or housings. Structures and equipment near bodies of water may experience ice loading higher than normal for the area. Water spray or wind, coupled with cold tem- peratures can create high ice loadings in short amounts of time. Access for maintenance and operation may be restricted by ice buildup.
Covers, snow screens, or local heating systems may be required to keep control equipment operational. Power and communications cable support, protection, and rout- ing should consider extreme ice loading in cold climates. Snow and ice may adversely impact opera- tion or exceed equipment design limitations. Conduit air vent heaters should be employed to maintain operation under iced conditions. Anti-icing bubbler systems may be utilized to reduce ice buildup on trash racks, level sensing equip- ment, submerged gates, and other structures. These systems are used to entrain air into the water up- stream of a surface to prevent formation of ice. Measures should be taken to protect gate operating mechanism power cabling and mechanical assem- bly.IEEE 1827 pdf download.IEEE 1827-2016 pdf download