Document bapYXGX8km1rrzR3y3dwx0NnD

INONEMAC IHN!E More TECHNICAL BRIEFS 9*qIu on psgt IH ally riimg coei of material and labor, larger equipment appears to be the best way of keeping unit capital and operatlng eosu down. ASME Paper No. S3-F-8. dittihni for trttttng ptptn to p lit El For QUALITY '.YLE-NATIOtlAL Electricity 0roundad Versus Undergroundod LowVoltage AC Syciome. By N B Thacker, Veitinghoute Electric Carp. Early Industrial-plant distribution ay* terns were almost all operated with (he neutral insulated. This permitted oper ation with a ground on some device or part of the circuit. Also, the uso of 440 or S50-v power-supplied from delta-con nected transformer banks and the higher cost of wye-connected throe-phase trans formers with the neulrol available for grounding discouraged the use of threophase four-wire grounded-neutral dlatribution systems. There has been a decided trend toward grounding low-voltage systems in industrial plants In the last ten years. Some reasons for this ore: (1) More positive location of ground faults by tripping out only the effected circuit, and (2) reduction In the possibility of multiple failures of equipment and cir cuits from overvoltages resulting from ground faults. Both of theso reasons have assumed greater importance with the tremendous growth In industrial systems and electric power use. A third reason tending to increase the use of grounded systems has been the development and use of higher-voltage lighting supplied at 265-v. This mikes attractive the uae of threephaoe, four-wire, 460 and 265-v wyeconnected distribution systems. This paper discusses advantages and disadvantages of grounded and un grounded systems bringing out that, in general, neutral grounding is preferred, but that under certain operating condi tions there are many applications where the ungrounded system provides an ad ditional and highly desirable degree of service continuity. Methods of ground ing both new and existing systems are discussed. AISE paper. No number. Cathodic Protection of Mill Oroundlng Systems. By ] F Htadlee, United State* Steel Corp. Great improvements hove been made in circuit and equipment grounding sys tems. Two sources cause electrolysis in sueh a system; stray currents from dc generators and golvanio currents from two unlike materials in electrolyte. urbines !4 to 120 h.p. The Pyle-Nalional line of highly efficient Impulse type turbines is idoal for dopondable mechanical drive of small machinery snob as pumps, fans, blowers, stoker* abrasive wheels, agitators, and generators particularly where the exhaust steam can be used for heating and othor purposes. Since 1897 Pyle-National has manufactured their turbines 'entirely within their own plant ...thus assuring positive control of quality ond work manship through all stages of production ... from row material to the final testing. BEND NOW FOB BOLLETINM containing complete informa tion on these small and me dium capacity turbines. TURBO-GENEBATOBS Also available is bulletin on Pylo-NaUonal turbogener ators (500 to 15000 watte). $THE PYLE* NATIONAL COMPANY Jr N.KOSTNII AVI CMtCAOO Si Nifrirl Offfcvt ead hpfiiwloilwi b* Prfcdpd CUIti ! lb* UnOod Stott* POWER oecembh [HI-LO (..helps to prevent SURGE or HAMMER during closure of valves .. tesij JV/JI The name L/m/forque hoi been for years synonymous with dependable MOTORIZED VALVE OPERATION In Rofineries, Pipe lines, Power Plants, Water and Sewage Worky . . . throughout the World. Now, o device Is available for use with Umlforqve which permits o valve to be operated ot 2 different speeds. This device, known as the "HI-LO" attach ment permits the speed of the valve stem to be VARIED AT ANY PRE-DETERMINED POINT ... or H required, the valve may be opened at one fixed speed and dosed ot another predetermined speed. "HI-10" Is a device which prevents! # DAMAGE to valves ond station pumps, o BREAKS In pipeline caused by "surge". 0 DAMAGE to expensive equipment. O INJURIES to personnel. "HI-LO" Is a device which minimises or com pletely ellmlrtatost O LINE "SURGE*' OR "HAMMER" during closure. O NECESSITY OF BY-PASS VALVES because of greotly Increased torque during initial valve opening. ELEMENT OF HUMAN ERROR, to o great extent, In operation. The 2-Speod "HI-LO" is new, different, exchitlve, and when comblnod with Umlforquo, gives simple, pos itive, automatic ond safe motorized volvo operation. Above illustration shows a 20" Gete Valve with first 9/IOths of travel dosed In 4J seconds--end last 1/1 Oth of travel to close In 70 seconds. However, change from high to low speed can be made at any pro-determined point of travel. Operation con alto be fixed to obtoln one speed dosing, and one speed (either foster or slower) In opening of valve. r toWCR OECEMBER 1953 INC. BRIE AVB. AND G ST., PHILADELPHIA 34, PA. saw yoRK * pimeuROM * chicaoo Houston ivnchuo. va. Industrial Gcbis,ond Speed Reducers' Limi7orQ*ue VdlvQ Controls 347