6 28. three 33. nine 36. eight 39. 6 forty five. 2 50. four fifty six. five sixty five eighty five. eight ninety five. four 111. four 114. five 127. 2 one hundred forty five. five 151 167. nine 201. four — — — 2. 07–2. forty nine 2. 65–2. ninety nine three. 15–3. forty eight three. 57–3. ninety eight four. 40–4. ninety eight five. 31–5. ninety seven five. 81–6. forty seven 6. 22–6. ninety seven 7. 13–7. ninety six eight. 05–8. 87 eight. 96–9. ninety five — — — — — — — — — — — — — forty three. eight fifty two. 6 sixty one. 2 70 87. 6 118. 2 128. 1 a hundred thirty five 157. 6 one hundred seventy five. 6 197 — — — — — — — — — — — — — resource: Courtesy of normal electrical. one hundred twenty bankruptcy SIX to flee. If the motor is lower than third horsepower, the enclosure should be explosion-proof nonventilated (EPNV); if the motor is greater, an explosion-proof fan-cooled enclosure (EPFC) is generally used. Open Enclosure. Open (OP) enclosures are used interior in fresh destinations. air flow openings in finish shields and/or within the shell allow the passage of cooling air over and round the windings. the site of the openings isn't really constrained. absolutely Enclosed. In a wholly enclosed (TE) housing, there aren't any openings within the motor housing, however it isn't hermetic. this sort of housing is utilized in destinations which are soiled, oily, and so forth. There are forms of completely enclosed housings: completely enclosed fan-cooled (TEFC), that have a fan to blow cooling air over the motor, and absolutely enclosed non-ventilated (TENV), which aren't outfitted with a fan and rely on convection air for cooling. 7 energy assets strength is generated commercially as three-phase. it really is allotted from the producing plant to the substation close to the group that makes use of it as three-phase. Then it truly is taken from the substation as single-phase and disbursed in the neighborhood to houses and farms. it really is generated at 13,800 volts on the producing plant after which stepped up from 138,000 to as excessive as 750,000 volts to be dispensed over lengthy distances. See determine 7-1. THREE-PHASE (3Φ ) strength Three-phase strength is out there from electric utilities. it may be delivered to the farm, office, tuition, or commercial plant and used as three-phase, or it may be introduced as such after which damaged down into single-phase for the apparatus positioned at the premises. Three-phase strength is pricey to put in inasmuch because it makes use of varied transformers and extra wires than single-phase strength. so much farms use three-phase provided that the farm is found close to a college or manufacturing unit with that carrier. they can use single-phase given that they don’t frequently have cars rated over five horsepower. POLYPHASE turbines those turbines are often hired through hospitals and industries for emergency strength. those turbines are huge devices pulled Copyright © 2005 by way of The McGraw-Hill businesses, Inc. click on right here for phrases of use. bankruptcy SEVEN excessive voltage distribution in towns Transformer Substation huge factories residences workplace constructions and big shops Underground cable Manhole producing plant Generator Oil change 13,200 volts Steam Steam turbine Coal Boiler Flue Water High-voltage transmission 13,200 volts 122 Condenser 132,000 volts 2,300/4,000 volts Transformer Step-up substation zero/ 12 Step-down substation zero 24 lts vo Farms 120/240 volts houses shops colleges Low-voltage residential and advertisement distribution determine 7-1.