IEEE C57.32-2015 pdf free.IEEE Standard for Requirements,Terminology, and Test Procedures for Neutral Grounding Devices.
The clearance requirements are of three types: electrical, ventilation, and magnetic.
As the normal dry-type air-core neutral grounding reactor has exposed livc parts at essentially all points on its outer surface, provision must be made for electrical clearance from the reactor surface to nearby grounded surfaces and to other adjacent energized conductors. Standard electrical clearances to live parts arc adequate. No spccial precautions over and normal substation practices arc required.
Ventilation clearance requirements may vary somewhat depending on the reactor manufacturer. For instance, in the case of reactors employing vertical cooling ducts, provision must be made ftr the unimpeded entrance and exit of cooling air at the bottom and top of the cooling ducts, respectively. In some cases baffles are required for establishing sufficient cooling convection through the reactor ducts during conditions of consistent crosswinds. Generally, the ventilation clearance will be less than the magnetic clearance requirements and, as such, it will not prove to be a limiting factor when installing the unit. Irrespective of this fact, it is still important to recognize that there is a requirement for sufficient ventilation and the blockage of the cooling ducts with any Ibreign material, metallic or non-metallic, or interference with normal convective airflow must be avoided.
Magnetic clearance requirements arise since dry-type air-core reactors have no iron core to capture the magnetic field. However, since continuous kVA ratings and hence continuous stray magnetic fields of neutral grounding reactors arc relatively small, electrical clearances arc usually greatcr than magnetic clearances. Nevertheless, during conditions when reactors carry thermal and mechanical peak currents, induced forces in large metallic objects or closed electrical loops near the reactors should be evaluated. Information regarding recommended magnetic clearances can usually be obtained from the equipment manufacturer and is otlen supplied on reactor outline drawings.
Neutral grounding reactors may also be mounted directly on transformer tanks. In this case, possible elevated ambient temperatures and the magnetic clearance required to the transformer tank need to be taken into consideration in the reactor design. Therefore, it is important that the reactor specification includes details regarding the reactor mounting site on the transformer lank, tank dimensions, and expected ambient temperature range at the location where the reactor is to be installed.
4.4 Mechanical considerations
l)cpending on the scope of supply, special attention should be given, by either the manufacturer or purchaser, to the interactive electromagnetic forces between the reactor and current carrying auxiliary parts (such as buswork) and between the reactor and bus or cable connections to the reactor. Support structure and bracing elements must be designed to resist the resultant loads.
As standard practice. unless otherwise specified, peak wind loads and seismic loads or other specified loading arc typically assumed to act on a non-coincidental basis.
Reactors should be designed to facilitate lifting and should be provided with lifting eyes or similar devices to allow safe and rapid installation. Lifling and handling instructions should be clear and readily available.IEEE C57.32 pdf free download.