Medium Voltage. Fuses. Fuses Medium Voltage Contents

Transcription

1 September Sheet 000 smedum Voltage.0- s Medum Voltage Contents smedum Voltage General Descrpton Lmtng s Expulson s Techncal s Specfcatons See Eaton s Product Specfcaton Gude, avalable on CD or on the Web. CSI Format: Secton Secton Lmtng s CA000E For more nformaton, vst:

2 .0- smedum Voltage September Sheet 000 General Descrpton Medum Voltage s Eaton s entry n the power fuse busness began over years ago under Westnghouse Electrc. In, Westnghouse ntroduced the medum voltage borc acd expulson fuse followed by the medum voltage current lmtng fuse. Even today, medum voltage fuses contnue to use the core Westnghouse technology. Eaton contnues to buld on the Westnghouse technology legacy by engneerng hgher performance, cost-effectve power fuse products. Eaton medum voltage fuses are manufactured and tested to the requrements of the ANSI C.X seres of standards. Eaton s the only North Amercan manufacturer of both current lmtng and expulson medum voltage power fuses. A full range of general purpose, backup and borc acd fuses s avalable for dstrbuton and power applcatons. All Eaton medum voltage fuses are thoroughly tested and conform to ANSI specfcatons. Some motor starter fuses are UR recognzed, and both current lmtng and expulson fuses have been approved n UL rated swtchgear. lmtng and expulson fuses can be used to meet any overcurrent protecton need. At any pont along the medum voltage electrcal dstrbuton system, Eaton has a fuse to satsfy your overcurrent protecton needs. The followng fuse termnology wll assst n understandng and selectng the correct fuse. The followng s a bref overvew of those terms. Power vs. Dstrbuton The dfferentaton s ntended to ndcate the test condtons and where fuses are normally appled n a power system, based on specfc requrements for generatng sources, substatons and dstrbuton lnes. Each class has ts own unque set of voltage, current and constructon requrements (see ANSI C.,. and.). Low vs. Medum vs. Hgh Voltage Whle fuses are defned n the ANSI standards as ether low or hgh voltage, Eaton s Electrcal Sector has elected to name ther fuses to correspond wth the equpment n whch they are nstalled. Therefore, per ANSI C, fuses are named as follows: Low Voltage Medum Voltage Hgh Voltage 00V and below Greater than 00,000V Greater than,000v Expulson vs. Lmtng Expulson : An expulson fuse s a vented fuse n whch the expulson effect of the gases produced by nternal arcng, ether alone or aded by other mechansms, results n current nterrupton. An expulson fuse s not current lmtng and as a result lmts the duraton of a fault on the electrcal system, not the magntude. Lmtng : A current lmtng fuse s a fuse that, when ts current responsve element s melted by a current wthn the fuse s specfed current lmtng range, abruptly ntroduces a hgh resstance to reduce current magntude and duraton, resultng n subsequent current nterrupton. Table.0-. General Comparson Expulson Lmtng Vented Electromechancal Interrupts at current zero, lmts fault current duraton Generally hgher voltage ratngs Dfferent tme/current characterstcs Sealed Statc Lmts fault current magntude and duraton Generally hgher nterruptng ratngs Dfferent tme/ current characterstcs For more nformaton, vst: CA000E

3 September Sheet 000 smedum Voltage.0- Table.0-. Eaton Medum Voltage Famly Lmtng HLE: Helcal confguraton current lmtng, E-rated : lmtng, E-rated CLS: lmtng starter (motor starter) HCL: lmtng, clp-mount, E-rated CX: lmtng, C-rated CLPT: lmtng, E-rated Expulson RBA: Refllable, borc acd RDB: Refllable, dropout, borc acd DBU: Dropout, borc acd, ndoor/outdoor S&C equvalent Table.0-. Applcaton Gude Type Voltage Ampere Range (kv) Lmtng Maxmum Interruptng (ka Sym.) Class Use Indoor/Outdoor.. 0A General purpose ndoor/outdoor CLPT. 0.E 0 General purpose ndoor CLS.. R R 0 Backup dstrbuton ndoor CX/CXI...C 00C 0 General purpose dstrbuton ndoor HCL.. A 00A General purpose dstrbuton ndoor HLE.. General purpose ndoor/outdoor Expulson s RBA. 0.E. Borc acd power ndoor RDB. 0.E. Borc acd power outdoor DBU. E, K 0K 0 Borc acd power ndoor/outdoor Appled n: d swtches, feeder crcut sectonalzng, power transformers, dp poles, substaton capactor banks. Potental transformers. BAL- mountngs and clps are no longer avalable. AMPGARD and non-ampgard motor starters. HCLS verson s the same as the CLS except hermetcally sealed for hazardous locatons. Pad mounted dstrbuton transformers, Substaton servce transformers, and fused swtches. Drect substtuton for McGraw s NX fuse. d swtches, feeder crcut sectonalzng, power transformers, dp poles, substaton capactor banks. d swtches, feeder crcut sectonalzng, power transformers, dp poles, substaton capactor banks. d swtches, feeder crcut sectonalzng, and power transformers. Feeder crcut sectonalzng, power transformers, substaton servce transformers, dp poles, potental transformers, and substaton capactor banks. Outdoor verson of the RBA. Feeder crcut sectonalzng, fused swtches, power transformers, substaton servce transformers, dp poles, and potental transformers. Drect equvalent for S&C s SMU- fuse unts. Table.0-. Power Ampere Characterstc s Defnton E s rated or below wll melt n 00 seconds at some current value between.0 and. tmes the E number. s rated above wll melt n 00 seconds at some current value between. and. tmes the E number. R The fuse wll melt n to seconds when the current equals 0 tmes the R number. C The fuse wll melt n 00 seconds at some current value between. and. tmes the C number. A Class A fuses have parameters that do not fall wthn the C, E, or R defntons above. X Meet C.0 temperature requrements, but not the E ratng. CA000E For more nformaton, vst:

4 .0- smedum Voltage September Sheet 000 Lmtng s Lmtng Types There are three current lmtng fuse types: backup, general purpose and full range. It s mportant that the user have an understandng of these defntons to ensure proper applcaton of the fuse (Fgure.0-). Backup : A fuse capable of nterruptng all currents from the rated maxmum nterruptng current down to the rated mnmum nterruptng current. Backup fuses are normally used for protecton of motor starters and are always used n seres wth another nterruptng devce capable of nterruptng currents below the fuse s rated mnmum nterruptng current. General Purpose : A fuse capable of nterruptng all currents from the rated maxmum nterruptng current down to the current that causes meltng of the fusble element n no less than one hour. General purpose fuses are typcally used to protect feeders and components such as transformers. Range : A fuse capable of nterruptng all currents from the rated maxmum nterruptng ratng down to the mnmum contnuous current that causes meltng of the fusble element, wth the fuse appled at the maxmum ambent temperature specfed by the manufacturer. lmtng fuses are constructed wth pure slver fuse elements, hgh purty slca sand fller, and a glass resn outer casng. A hgh fault current melts the slver element almost nstantly and loses energy to the surroundng sand. The sand melts and forms fulgurte, a glass-lke substance. The arc voltage rapdly ncreases to nearly three tmes the fuse voltage ratng and forces the current to zero. Low fault current melts a solder drop on the slver fuse element that, n turn, melts the slver. The element burns back untl there s a suffcent nternal gap to nterrupt the current. Ths s known as the M-effect. Eaton offers current lmtng fuses n two basc types: backup and general purpose. Backup fuses are appled n seres wth another crcut protectve devce, such as a contactor or an expulson fuse, to nterrupt hgh fault currents beyond the other devce s range. General purpose fuses are desgned to nterrupt low fault currents that cause them to melt n one hour or less. Mult-Range s and HLE fuses are also avalable n user-selectable mult-range versons 0A, 0 A and 0A. Dsconnect End Fttngs and Dsconnect Lve Parts Accessores A wde assortment of mountngs, lve parts and end fttngs are avalable to facltate power fuse nstallaton. Mountngs Mountngs nclude a base, porcelan or glass polyester nsulators, and lve parts. They help enable the fuse to be safely attached to the gear. Mountngs can be ether dsconnect or non-dsconnect. Lve Parts Lve parts attach the fuse to the nsulators and are consdered part of the mountng. All parts above the nsulators are lve parts. Lmtng Type max. rated maxmum nterruptng current mn. rated mnmum nterruptng current hr. current causng element meltng n hour any current meltng element wth no tme lmt mn. Backup General Purpose Range Interruptng hr. max. Fgure.0-. Lmtng Types Protecton Range For more nformaton, vst: CA000E

5 September Sheet 000 smedum Voltage.0- Lmtng s Table.0-., HLE, HCL and CLS s Descrpton Famly HLE HCL CLS General Class General purpose General purpose General purpose Backup Use Power Power Power Power Maxmum kv Maxmum ka 0 0A 0A 00E R R Mountng Clp Clp, bolt-on, hookeye Clp lock, bolt-on Clp, bolt-on, hookeye Indcator Standard Standard Standard Standard Approvals IEEE, ANSI IEEE, ANSI IEEE, ANSI UL, IEEE, ANSI Applcatons Feeder crcuts Motor starters PTs and CTs LV breakers Substaton servce Transformers Capactor banks d swtches Table.0-. CLPT, CX, CLT and DSL s Descrpton Famly CLPT CX CLT DSL General Class General General General Back-up Use Power/dstrbuton Dstrbuton Dstrbuton Power Maxmum kv V Maxmum ka E.C 00C Mountng Clp Clp Stud bolt-on Bolt-on Indcator Optonal None None None Approvals IEEE, ANSI IEEE, ANSI IEEE, ANSI UL Applcatons Feeder crcuts Motor starters PTs and CTs LV breakers Substaton servce Transformers Capactor banks d swtches CA000E For more nformaton, vst:

6 .0- smedum Voltage September Sheet 000 Expulson s RBA E-Rated Refllable Borc Acd Eaton s expulson fuses use borc acd as the nterruptng medum. Under a fault condton, arc heat decomposes the borc acd nto water vapor. The water vapor blast deonzes the arc path preventng arc re-gnton after a natural current zero. Type RBA ndoor expulson fuses must be ftted wth a dscharge flter or condenser that moderates the dscharge exhaust. The dscharge flter lmts the exhaust to a small and relatvely nert amount of gas and lowers the nose level wthout affectng the fuse nterruptng ratng. Steam dscharge, that can effect the nterruptng, s fully restrcted by the condenser. Type RDB outdoor dropout fuses nclude an ejector sprng that forces the arcng rod through the top of the fuse. The arcng rod strkes a latch on the mountng that forces the fuse to swng outward through a 0 arc nto the dropout poston. Refll unts can be feld nstalled nto RBA and RDB expulson fuses. Once the operated unt has been removed, the separately purchased unt can be easly nstalled nto the fuse holder. Accessores The followng accessores are avalable for expulson fuses: Mountngs Mountngs nclude a base, porcelan or glass polyester nsulators, and lve parts. They help enable the fuse to be safely attached to the gear. Mountngs can be ether dsconnect, non-dsconnect or dropout. Non-dsconnect mountngs are avalable n ether bolt-on or clamptype arrangements. s may be vertcal or underhung. Lve Parts Lve parts attach the fuse to the nsulators and are consdered part of the mountng. All parts above the nsulators are lve parts. End Fttngs End fttngs are metal parts that attach to each end of the fuse at the ferrules. They are used only on dsconnect fuses or when convertng a non-dsconnect to a dsconnect fuse. RDB E-Rated Refllable Outdoor Dropout Borc Acd Type DBU fuse unts are desgned for new and aftermarket utlty applcatons. End fttngs are avalable, n both ndoor and outdoor versons, as well as lve parts and mountngs. Mufflers confne the arc wthn the fuse and substantally reduce the nose and exhaust when the fuse nterrupts. DBU Dropout Borc Acdfor Use Indoors, Insde Swtchgear or Outdoors For more nformaton, vst: CA000E

7 September Sheet 000 smedum Voltage Techncal s.0- Techncal s Table.0-. Transformer Prmary Applcaton System Maxmum Transformer kva Voltage Type Self-Cooled Forced Ar 00 lmtng lmtng 00 lmtng 00 lmtng 0 lmtng 0 0 Expulson 00 0 Expulson Expulson 0 0 Expulson 0 Expulson Maxmum transformer kva ratngs are based on ratos of maxmum fuse current ratng to transformer full load current (I F /I T ) as lsted. For a C rse lqud-flled transformer, use the kva ratng for C rse ( C ratng x.). For suggested mnmum fuse applcatons, see Tables.0-,.0- and.0-. The type RBA nterruptng ratngs shown are those of the dscharge flter type, n whch the nose s mnmzed and deonzaton of expulson gases s assured. These applcatons are subject to modfcaton when specfc factors such as transformer characterstcs, other protectve devces, coordnaton requrements and load varatons may ndcate a dfferent I F /I T rato Famly/Characterstcs Type Range -0-0 RBA-0 RBA-00 RBA-00 DBU- /HLE /HLE -0-0 RBA-0 RBA-00 RBA-00 DBU- /HLE /HLE -0-0 RBA-0 RBA-00 RBA-00 DBU- /HLE RBA-0 RBA-00 RBA-00 DBU- /HLE /HLE /HLE RBA-0 RBA-00 RBA-00 DBU- Cauton: Prmary fuses must not be reled upon for clearng secondary ground faults Maxmum kv Interruptng Amperes (Symmetrcal).,000,000 0,000,00..,000,00,00.,000.,000,000 0,000,00..,000,00,00.,000.,000,000 0,000,00..,000,00,00,000..,000,00,00,000..,000,00,00.,000 CA000E For more nformaton, vst:

8 .0- smedum Voltage Techncal s September Sheet 000 Techncal s (Contnued) Table.0-. Transformer Prmary Applcaton (Contnued) System Maxmum Transformer kva Voltage Type Self-Cooled Forced Ar,000 lmtng,0 lmtng,00 lmtng Expulson 0 Expulson 0 Expulson 0,000 Expulson 0 0,00 Expulson 00 Maxmum transformer kva ratngs are based on ratos of maxmum fuse current ratng to transformer full load current (I F /I T ) as lsted. For a C rse lqud-flled transformer, use the kva ratng for C rse ( C ratng x.). For suggested mnmum fuse applcatons, see Tables.0-,.0- and.0-. The type RBA nterruptng ratngs shown are those of the dscharge flter type, n whch the nose s mnmzed and deonzaton of expulson gases s ensured. These applcatons are subject to modfcaton when specfc factors such as transformer characterstcs, other protectve devces, coordnaton requrements and load varatons may ndcate a dfferent I F /I T rato Cauton: Prmary fuses must not be reled upon for clearng secondary ground faults. Table.0-. Selecton of Mnmum Prmary for Transformer Protecton Instructons: Multply the transformer prmary full load current (FLA) tmes the multpler shown n the table to determne suggested mnmum sze fuse. Use fan-cooled prmary FLA wth forced ar transformer multpler. See Tables.0- thru.0- for suggested mnmum fuse sze. Type current lmtng fuses All ratngs Type RBA, DBU expulson type fuses Famly/Characterstcs Type Range HLE HLE RBA-0 RBA-00 RBA-00 DBU- HLE HLE RBA-0 RBA-00 RBA-00 DBU- HLE HLE RBA-0 RBA-00 RBA-00 DBU- RBA-0 RBA-00 RBA-00 DBU- RBA-0 RBA-00 RBA-00 DBU- For self-cooled transformers. x FLA of XFMR For forced ar transformers. x FLA of XFMR Maxmum kv.,000,000,000,000.,00,00,00,000.,000,000,000,000.,00,00,00,000.,000,000,000, Interruptng Amperes (Symmetrcal),00,00,00,000,00,000,000,00.0,00,00,00,000 For more nformaton, vst: CA000E

9 September Sheet 000 smedum Voltage Techncal s.0- Interruptng s of s Modern fuses are rated n amperes rms symmetrcal. They also have a lsted asymmetrcal rms ratng, whch s. x the symmetrcal ratng. Refer to ANSI/IEEE C. for fuse nterruptng duty gudelnes. Calculaton of the fuse requred nterruptng ratng: Step Convert the fault from the utlty to percent or per unt on a convenent voltage and kva base. Step Collect the X and R data of all the other crcut elements and convert to percent or per unt on a convenent kva and voltage base same as that used n Step. Use the substransent X and R for all generators and motors. Step Construct the sequence networks usng reactances and connect properly for the type of fault under consderaton and reduce to a sngle equvalent reactance. Step Same as above except usng resstances (omt f a symmetrcally rated fuse s to be selected). Step Calculate the E/X I value, where E s the prefault value of the voltage at the pont of fault normally assumed.0 n pu. For three-phase faults E/X I s the fault current to be used n determnng the requred nterruptng capablty of the fuse. Note: It s not necessary to calculate a sngle phase-to-phase fault current. Ths current s very nearly / x three-phase fault. The lne-to-ground fault may exceed the three-phase fault for fuses located n generatng statons wth soldly grounded neutral generators, or n delta-wye transformers wth the wye soldly grounded, where the sum of the postve and negatve sequence mpedances on the hgh voltage sde (delta) s smaller than the mpedance of the transformer. For sngle lne-to-ground fault; X I = X I (+) + X I (-) + X I (0) E I f = ---- X I Step Select a fuse wth a publshed nterruptng ratng exceedng the calculated fault current. Table.0- should be used where older asymmetrcally rated fuses are nvolved. The voltage ratng of power fuses used on three-phase systems should equal or exceed the maxmum lneto-lne voltage ratng of the system. lmtng fuses for three-phase systems should normally be appled so that the fuse voltage ratng s equal to or less than. x nomnal system voltage. However, the nsulaton levels on. kv systems normally allow. or. kv rated fuses to be used. Table.0-. Suggested Mnmum Lmtng s for Self-Cooled.. kv Transformer ApplcatonsE-Rated s System Nomnal kv s Maxmum kv Transformer kva Self-Cooled , E E 00E 00E 00E E E 00E E E E Note: ratngs represent the fuse that wll wthstand transformer nrush ( x FLC for 0. second and x FLC for 0.0 second) and be able to handle temporary overloads (% of FLC, % for. kv) E E E E E E E E CA000E For more nformaton, vst:

10 .0- smedum Voltage Techncal s September Sheet 00 Table.0-. Suggested Mnmum RBA Expulson s for Self-Cooled.. kv Transformer ApplcatonsE-Rated s System Nomnal kv s Maxmum kv Transformer kva Self-Cooled , E 00E E 00E E E 00E Two -ampere fuse refll unts n parallel wth % deratng. Two 00E-ampere fuse refll unts n parallel wth % deratng. Two -ampere fuse refll unts n parallel wth % deratng. Note: ratngs represent the fuse that wll wthstand transformer nrush ( x FLC for 0. second and x FLC for 0.0 second) and be able to handle temporary overloads (% of FLC, % for. kv). Table.0-. Suggested Mnmum RBA Expulson s for Self-Cooled. kv Transformer Applcatons System.... Nomnal kv s... Maxmum kv Transformer kva Self-Cooled , E E E E 00E E E Two -ampere fuse refll unts n parallel wth % deratng. Note: ratngs represent the fuse that wll wthstand transformer nrush ( x FLC for 0. second and x FLC for 0.0 second) and be able to handle temporary overloads (% of FLC, % for. kv) E E 00E E E E E E E E E E E For more nformaton, vst: CA000E

11 September Sheet 00 smedum Voltage Techncal s.0- Table.0-. Suggested Mnmum DBU Expulson s for Self-Cooled.. kv Power Transformer Applcatons System Nomnal kv s Maxmum kv Transformer kva Self-Cooled Three-Phase Transformers E E Note: ratngs represent the fuse that wll wthstand transformer nrush ( x FLC for 0. second and x FLC for 0.0 second) and be able to handle temporary overloads (% of FLC, % for. kv). Table.0-. Suggested Mnmum DBU Expulson s for Self-Cooled.. kv Power Transformer Applcatons System.... Nomnal kv s Maxmum kv Note: ratngs represent the fuse that wll wthstand transformer nrush ( x FLC for 0. second and x FLC for 0.0 second) and be able to handle temporary overloads (% of FLC, % for. kv). Table.0-. Type DBU Expulson s, Borc Acd, Indoor/Outdoor E E Transformer kva Self-Cooled Three-Phase Transformers Maxmum Desgn kv 0 Amperes 0 E Note: Used on overhead dstrbuton transformers, substaton equpment, ndustral transformer nstallatons, and radal dstrbuton crcuts. E. K, K, K, K, K, K, K, K, 0K, 0K, 0K, K, 0K, 0K, 0K, 0K, E, E,, E, E,, E,,,,,,,,, E,, SE, SE, SE, 0SE, 0SE, 0SE, SE, 0SE, 0SE, SE, SE, SE, 0SE K, K, K, K, K, K, K, K, 0K, 0K, 0K, K, 0K, 0K, 0K, 0K, E, E,, E, E,, E,,,,,,,,, E,, SE, SE, SE, 0SE, 0SE, 0SE, SE, 0SE, 0SE, SE, SE, SE, 0SE K, K, K, K, K, K, K, K, 0K, 0K, 0K, K, 0K, 0K, 0K, 0K, E, E,, E, E,, E,,,,,,,,, E,, SE, SE, SE, 0SE, 0SE, 0SE, SE, 0SE, 0SE, SE, SE, SE, 0SE E E E E E E Interruptng rms (ka Symmetrcal). outdoor. ndoor wth muffler E E For addtonal nformaton, see: Volume, CA0000E Tab CA000E For more nformaton, vst:

12 .0- smedum Voltage September Sheet 00 Ths page ntentonally left blank. For more nformaton, vst: CA000E