Blocks and Holders Fuse Blocks General Information 4. Determine if NEC, CSA, UL, or other requirements are applicable If fuse blocks will be installed in equipment to be submitted for agency approval, the requirements should be obtained from the approving agency in advance of fuse and fuse block selection. 5. Select the type of wire termination A choice of three types of wire termination is available: a) Screw* — for use with spade lugs or ring terminals. b)Screw with Pressure Plate* — for use with solid or stranded wire without terminal. Recommended where vibration will be a factor. c) Box Lug — the most durable. For use with all types of solid wire and Class B and Class C stranded wire. Not for use with welding cable or other rope-stranded conductors. * 1/4” Quick Connect terminals rated for up to 20A are available on the Midget and Class CC fuse blocks. Fuse Block Selection The following guidelines should help simplify the selection of proper fuse blocks: Screw with Pressure Plate (P) 1. Determine the system voltage Since fuses are selected on the basis of system voltage, fuse blocks are selected to match the voltage rating of the fuse. Screw (S) Box Lug (C) 6. Decide on the number of poles in each block 2. Determine the design short-circuit current Class H fuse blocks will accept Class H or K5 fuses (which have an interrupting rating of up to 50,000 amperes) and Class R fuses (which have a 200,000 A.I.R.). To prevent the possibility of inserting a fuse with the incorrect interrupting rating, the use of Class R fuse blocks is recommended for use with Class R fuses. Use Class H fuse blocks with Class H or K5 fuses. These fuse blocks are dimensionally the same, but the Class R fuse blocks incorporate a rejection feature which allows only Class R fuses to be inserted. The number of poles for each set of fuses is determined by the characteristics of the circuit. The option to gang individual fuse blocks into long strips will be determined by the available space and by the type of wire being used. Blocks and Holders Available and/or design short-circuit current is an important consideration when determining the class of fuse and fuse blocks to use. If available short-circuit current cannot be determined, or if it will vary with equipment location, select fuses with a 200,000 ampere interrupting rating (A.I.R.) and mating fuse blocks with a withstand rating of 200,000 amperes for maximum safety. 7. Determine if fuse clips need to be reinforced Fuse clips may have a tendency to lose some of their tension over a period of time. This may be prevented by specifying reinforced fuse clips. Reinforced clips are standard on certain fuse blocks (see individual product pages). Ordering Information The Littelfuse fuse block part number consists of 6 or 7 components, as shown below and in the individual fuse block data tables. 3. Determine the type and ampere rating of the fuse to be used In addition to voltage and interrupting rating as discussed above, the fuse ampere rating, opening characteristics (fast acting or time-delay) and size are other important considerations in fuse selection. Once the fuse type is selected, the mating fuse block can be chosen. Fuse blocks are available in 30, 60, 100, 200, 400 and 600 amp ratings, and may be used with a fuse rated at the corresponding amperage rating or below. For example, a fuse block rated at 30 amperes may be used with a fuse rated from 0 to 30 amperes. For all Class R, H, J, T and 15, 20 & 60A Class G Fuse Blocks © 2005 Littelfuse • POWR-GARD™ Products Catalog www.littelfuse.com For all Class CC, Midget and 30A Class G Fuse Blocks 111 Blocks and Holders Class J Fuse Blocks 600 Volt Class J 600V Amp Rating No. of Poles Catalog Number Connector Type Maximum Wire Size (Add Suffix Shown) Pressure Box Screw Plate Lug 1 LJ60030-1 S (R) P (R) C (R) 2 LJ60030-2 S (R) P (R) C (R) S & P = #10 CU 30 C = #6 CU 3 LJ60030-3 S (R) P (R) C (R) Adder LJ60030-A S (R) P (R) C (R) 1 LJ60060-1 C (R) 2 LJ60060-2 C (R) 60 C = #2 CU-AL 3 LJ60060-3 C (R) 1 LJ60100-1 CR 100 #2/0 CU-AL 3 LJ60100-3 CR 1 LJ60200-1 C 200 250 MCM CU-AL 3 LJ60200-3 C 1 LJ60400-1 CR 400 (2) 350 MCM CU-AL 3 LJ60400-3 CR 1 LJ60600-1 CR 600 (2) 500 MCM CU-AL 3 LJ60600-3 CR Note: Reinforcing springs standard on all Class J fuse blocks rated 100A and above. *For optional fuse block covers, refer to POWR-Covers section of this catalog. For reinforcing clips on blocks rated 30-60 amp, add “R” suffix to connector type. Specifications Features/Benefits Voltage Ratings: Ampere Ratings: Approvals: LJ60030 1.69" [7.6] 1.69" [42.8] 3.38" 3.38" [85.7] [85.7] [85.7] .30" TYP. 1.04" [26.4] [42.8] 3.38" .57" 1.16" JTD_ID/JTD (time-delay) and JLS (fast acting) series fuses [26.4] 1.69" [42.8] Recommended Fuses 1.04" .216[5.5] x .79[20.0] SLOT MOUNTING HOLE [14.5] [29.4] 1 POLE © 2005 Littelfuse • POWR-GARD™ Products Catalog Blocks and Holders • Phenolic blocks have side barriers for isolation. • Spring reinforced fuse clips are standard on 100A and larger blocks. Reinforcing springs are optional on 30 and 60 amp blocks. • Space saving 30A design — Up to 45% smaller than existing 30A fuse blocks. 30A interlocking adder block available to create any number of poles (consult factory for availability). Integral DIN rail mount allows this block to be securely fastened to 35 mm “hat” type DIN rails without the use of tools. 600 Volts 0 – 600 amperes UL Listed: File No. E14721 CSA Certified: File No. LR73091 .57" TYP. 2.20" [14.5] 3.25" [82.5] [56.0] 2 POLE .71" 1.95" [17.9] [49.5] 3 POLE www.littelfuse.com 117 Blocks and Holders Class J Fuse Blocks 600 Volt LJ60060 1.67" 3.20" [42.4] 4.07" .265" x .325" SLOT [6.7 x 8.3] TYP. [120] 4.07" [103] 4.07" [103] 2.03" [103] 2.03" [51.7] 2.03" [51.7] .76" [19] 4.72" [81.2] .45" [12] [51.7] .76" [19] 1.53" [38.8] 1 POLE .45" [12] 1.53" [38.8] 1.53" [38.8] 3 POLE 2 POLE .57" .76" [14 ] [19] .45" [12] 2.09" [53.0] Blocks and Holders LJ60100 1 POLE LJ60200 1.31" 3.00" [76.2] [33.39] 3 POLE .34" THRU [8.6] .75" C'BORE [19.1] x .400" DP. [10.2] 6.13" [156] .50" [13] .62" 2.00" [50.8] 118 1 POLE 6J200 2.67" [16] [67.9] www.littelfuse.com 3 POLE © 2005 Littelfuse • POWR-GARD™ Products Catalog Blocks and Holders Class J Fuse Blocks 600 Volt LJ60400 1 POLE 3 POLE 1 POLE 3 POLE LJ60600 www.littelfuse.com Blocks and Holders © 2005 Littelfuse • POWR-GARD™ Products Catalog 119