Fuse and fuse block cross reference, and index 16 Contents Section Description page Fuse sizing for 600 V building electrical systems 2-3 Selective coordination 4 Low voltage, branch circuit fuse types and classes 5 We make what Glossary of common electrical terms 6-7 Electrical formulas 7 matters work * FuseFinder fuse and fuse block cross reference 8-9 Catalog number index 10-14 For information on products not contained in this catalog, contact Customer Satisfaction, toll-free, at 855-287-7626 (855-BUSSMANN) between 7:00 a.m. 6:00 p.m. Central time, M-F, or email Horseless carriages. World War BussCustSat Eaton.com. * II aircraft. NASA space shuttles. Electric vehicles. Over the past 100 years, Bussmann series products have protected the things that have propelled our world forward. And theyll continue to protect for the next 100 years. Because we never lose sight of what matters. And its our job to make sure it works. BUSSMANN SERIES FULL LINE CATALOG 1007 OCTOBER 2018 Eaton.com/bussmannseries 16-1 Cross reference and index16 Fuse and fuse block cross reference, and index 4. Feeder circuit with mixed loads. (430.63) Size fuse at sum of: Fuse sizing for 600 V building electrical systems a. 150% to 175% of the largest motors full-load current**, General guidelines are given for selecting fuse amp ratings for plus most circuits. For specific applications warranting other fuse sizing, b. 100% of all other motors full-load current**, plus the load characteristics and appropriate NEC sections should be considered. The selections shown here are not, in all cases, c. 125% of the continuous, non-motor load, plus the maximum or minimum amp ratings permitted by the NEC. d. 100% of the non-continuous, non-motor load Demand factors as permitted by the NEC are not included. Study the pertinent NEC sections noted by () and reference pertinent 5. Branch circuit with no motor load. (210.20) The fuse size footnotes. must be at least 125% of the continuous load plus 100% of the non-continuous load. Do not size larger than the conductors ampacity*. Recommended fuses: Low-Peak KRP-C Class L, time-delay, 601 to 6000 A 6. Motor branch circuit with overload relays. Where overload Low-Peak 250 V LPN-RK/600 V LPS-RK Class RK1, dual element, time-delay, up to 600 A relays are sized per 430.32 for motor running overload Fusetron 250 V FRN-R/600 V FRS-R Class RK5, protection, there are various alternatives: 1 dual element, time-delay, up to 600 A 6a. Motor branch circuit short-circuit and ground fault protection. (430.52) (most common). Size the fuse between 150 to 175% of the full load current.** Provides Feeder Feeder Feeder branch circuit short-circuit and ground fault protection only. Fuse with no with all with 10 8 2 3 4 11 > 600 A motor motor combo 6b. Motor branch circuit short-circuit and ground fault load load motor/ protection (430.52) as well as backup overload no motor Motor load protection. Size FRN-R and FRS-R Class RK5 dual-element, starter time-delay fuses at 125% and LPN-RK-SP and LPS-RK-SP overload relay Class RK1 dual-element, time-delay fuses at 130% of motor 6a 6b 7 12 full-load current or next higher size. This results in closer Large fuse sizing and provides some backup running overload M motor protection. In addition, it provides motor branch circuit short- circuit and ground fault protection. Sizing in this manner may result in better motor protection if the overload relays are not properly sized or calibrated. 5 5 5 M M M 7. Motor branch circuit with only fuse protection. Where the fuse is the only motor protection, the following FRS-R and FRN-R, Class RK5, fuses provide motor running overload protection (430.32) and short-circuit protection (430.52): Cont. Non- loads, cont. Motor 1.15 ser vice factor or 40C rise. Size the fuse at 110% lighting/ loads 7 5 7 7 5 to 125% of the motor full-load current on the name plate heating 430.6(a)(2) . Motor less than 1.15 ser vice factor or over 40C rise. Size M M M fuse at 100% to 115% of motor full-load current on the name 9 Continuous plate 430.6(a)(2) . loads Power factor 8. Large motor branch circuit. Fuse larger than 600 A. 436.52(c) correction and 430.52(c)(1) Exceptions 2(d) . For large motors, size Low- capacitor Peak KRP-C-SP time-delay fuse at 175% to 300% of the motor Dual-element, time-delay fuses full-load current**, depending on the starting method i.e., part- winding starting, reduced voltage starting, etc. Class CF (up to 400 A), and J, RK1 and RK5 ( up to 600 A) 9. Power factor correction capacitors. 460.8(b) . Size dual- For fuses above 600 A, use Class L time-delay fuses with element fuses as low as practical, typically 150% to 175% of ratings from 601-6000 A. While these fuses are not dual-element capacitor rated current. construction, the Bussmann series KRP-C-SP is a time-delay fuse. 10. Transformer primary fuse (without secondary fuse 1. Main service. Size fuse according to method in 4 below. protection). 450.3(b) When transformer primary current is equal to or greater than 9 amps, the dual-element, time-delay 2. Feeder circuit with no motor loads. (215.3) The fuse size fuse should be sized at 125% of transformer primary current or must be at least 125% of the continuous load plus 100% of the next size larger if 125% does not correspond to a standard the non-continuous load. Do not size larger than the conductors fuse size. Note: Secondary conductors must be protected from ampacity*. overcurrent damage per Article 240. 3. Feeder circuit with all motor loads. (430.62) Size the fuse at 11. Transformer primary fuse (with secondary fuse protection). 150% to 175% of the largest motors full load current** plus the 450.3(b) May be sized at 250% of transformer primary current full-load current** of all other motor s. if the secondary is fused per 12 below. 12. The secondary fuse is sized at no more than 125% of secondary full-load current. 450.3(b) Note: Secondary conductors must be protected at their ampacities per Article 240. 16-2 BUSSMANN SERIES FULL LINE CATALOG 1007 OCTOBER 2018 Eaton.com/bussmannseries