
CLASS H, K & R  250 & 600 VOLT/FUSE BLOCKS
CLASS H, K AND R FUSE BLOCKS
Ferraz Shawmut Class H, K and R Fuse Blocks 
accommodate all Class H, K and R 250 and 600V 
power fuses. A choice of screw, pressure plate, 
box and special order stud connectors fit a wide 
range of stranded or solid copper or aluminum 
wire. Insulators are either molded glass-filled 
polycarbonate (GFPC) or phenolic with verified 
dielectric strength in excess of 2500V. 30, 60 
and 100A fuse blocks feature a unique adder 
block which can be snapped onto 1-, 2- or 3-pole 
blocks to form multi-pole segmented blocks of as 
many poles as desired. All fuse clips are made of 
high conductivity tin-plated copper, with a choice 
of spring reinforced or non-spring reinforced clips 
in 30A and 60A. Clips 100A and above are spring 
reinforced.
RECOMMENDED FUSE USAGE
Class R Blocks (250V). . . . . . . . use with A2D-R, A2K-R, TR-R
Class R Blocks (600V). . . . . . . . use with A6D-R, A6K-R, TRS-R
Class H & K Blocks (250V) . . . . use with OT, RF, A2Y types 1 & 3
        OTN, CRN, NRN
Class H & K Blocks (600V) . . . . use with OTS, RFS, A6Y types 1 & 3
        CRS, NRS
Clip & Connector Types
30A & 60A CLIPS
SPRING 
REINFORCED: 
CLASS R
CONNECTORS
NON-SPRING
REINFORCED:
30A & 60A BOX
CONNECTORS
SPRING
REINFORCED:
30A & 60A BOX
Ratings
250VAC:   
➤
30A, 60A, 100A,  
200A, 400A, 600A
600VAC:   
➤
30A, 60A, 100A,  
200A, 400A, 600A
Short Circuit  
➤
Current Ratings: 
250 & 600VAC  
w/class H fuses - 10kA 
w/class K fuses - 50kA 
w/class R fuses - 200kA
CONNECTORS
SPRING
REINFORCED:
100A BOX
Approvals
All fuse blocks meet 
➤
the requirements of 
UL Std. 512
UL Listed,   
➤
Guide IZLT, File E52283
UL Recognized  
➤
Component   
Guide IZLT2, File E52283
CSA Certified  
➤
Class 6225, File 32169
CONNECTORS
SPRING 
REINFORCED: 
400A BOX 
IN-LINE CLIP
H
H
CLASS H & K
NON-SPRING 
REINFORCED
30A SCREW
30A PRESSURE 
PLATE
30A SCREW (R)
30A SCREW 
30A PRESSURE 
PLATE
H 21
H 21
200A BOX 
SIDE-CLIP
400A BOX 
SIDE-CLIP
600A BOX 
IN-LINE CLIP
 

CLASS H, K & R  600 VOLT/FUSE BLOCKS
Figure 1 Figure 2 Figure 3 Figure 4
Recommended mounting screws for all 30A and 60A fuse blocks: 1/4” (.250” dia.)
600 Volt, 30 & 60 Ampere Class H, K and R Fuse Blocks
            CATALOG NUMBER 
                 CONNECTOR     TYPE OF CLIP
          CLASS H & K  CLASS H & K  CLASS R    CONNECTOR 
 AMPERE      WIRE  NON-SPRING  SPRING  SPRING  FIG.  TORQUE 
 RATING  POLES  TYPE  RANGE  REINFORCED  REINFORCED  REINFORCED    In - lb
    ADDER      60300  60305  60305R  1 
    1  BOX  Al/Cu  60301  60306  60306R  2  35 
    2    #2-14  60302  60307  60307R  3 
    3      60303  60308  60308R  4
    ADDER      60310  60315  60315R  1 
    1  SCREW  Cu  60311  60316  60316R  2  20 
  30  2    #10-14  60312  60317  60317R  3 
  GFPC  3      60313  60318  60318R  4 
 INSULATOR 
    ADDER      60320  60325  60325R  1 
    1  PRESSURE  Cu  60321  60326  60326R  2  20 
    2  PLATE  #10-14  60322  60327  60327R  3 
    3      60323  60328  60328R  4
    ADDER      -  60355  60355R  1 
    1  BOX  Cu*  -  60356  60356R  2  35 
    2    #4-14  -  60357  60357R  3 
    3      -  60358  60358R  4
    ADDER      60600  60605  60605R  1 
    1  BOX  Al/Cu  60601  60606  60606R  2  45 
    2    #2-14  60602  60607  60607R  3 
  60  3      60603  60608  60608R  4 
  GFPC 
 INSULATOR  ADDER      -  60655  60655R  1 
    1  BOX  Cu*  -  60656  60656R  2  45 
    2    #4-14  -  60657  60657R  3 
    3      -  60658  60658R  4
H
H
Note: To convert 30A or 60A adder pole to single pole, use end barrier #U09361. 
* Fuse blocks have copper box connectors and clips and are for copper wires only. These are specifically designed with the same coefficient of expansion as copper wire 
 for improved heat cycling and meet or exceed OEM “no aluminum” specifications.
H 25
H 25
 

CLASS H, K & R  600 VOLT/FUSE BLOCKS
Figure 1 Figure 2 Figure 3 Figure 4 Figure 5
Recommended mounting screws: 
  All 100A-1/4” (.250” dia.) 
  200A, 1-pole - #10 (.190” dia.)
600 Volt, 100 & 200 Ampere Class H, K and R Fuse Blocks
                      CATALOG NUMBER 
                 CONNECTOR                 TYPE OF CLIP 
          CLASS H & K  CLASS R    CONNECTOR
 AMPERE      WIRE  SPRING  SPRING  FIG.  TORQUE 
 RATING  POLES  TYPE  RANGE  REINFORCED  REINFORCED    In - lb
    ADDER      61035  61035R  1 
    1  BOX  Al/Cu  61036  61036R  2  120 
  100  3    2/0-#6  61038  61038R  3 
 PHENOLIC 
 INSULATOR  ADDER      61005  61005R  1 
    1  BOX  Cu*  61006  61006R  2  50 
    3    2/0-#12  61008  61008R  3 
    1  BOX  AL/Cu  62001  62001R  4  375 
  200  3  SIDE-CLIP  350kcmil-#6  62003  62003R  5 
 PHENOLIC         
 INSULATOR  1  BOX  Cu*  62051  62051R  4  275 
    3  SIDE-CLIP  350kcmil-#6  62053  62053R  5     
  200A, 3-pole - 5/16” (.313” dia.)
Note: Adder poles can only be added to other fuse blocks. There is no end barrier to convert them to single pole fuse blocks. 
 * Fuse blocks have copper box connectors and clips and are for copper wires only. These are specifically designed with the same 
 coefficient of expansion as copper wire for improved heat cycling and meet or exceed OEM “no aluminum” specifications.
H 26
H 26
 

CLASS H, K & R  600 VOLT/FUSE BLOCKS
Recommended mounting 
screws for all 400A and 
600A fuse blocks: 5/16 
(.313” dia.)
Figure 1 Figure 2
Figure 5
Figure 3 Figure 4
Figure 6
600 Volt, 400 & 600 Ampere Class H, K and R Fuse Blocks
                       CATALOG NUMBER 
                 CONNECTOR                 TYPE OF CLIP
          CLASS H & K  CLASS R    CONNECTOR 
 AMPERE      WIRE  SPRING  SPRING  FIG.  TORQUE 
 RATING  POLES  TYPE  RANGE  REINFORCED  REINFORCED    In - lb
    1  BOX*  Al/Cu  64001  64001R  1  375 
    3  SIDE-CLIP  1000-250kcmil  64003  64003R  2 
    1  BOX*  Cu**  64051  64051R  1  375   
  400  3  SIDE-CLIP  1000-250kcmil  64053  64053R  2 
 PHENOLIC   
 INSULATOR  1  BOX  AL/Cu  64031  64031R  3  275 
    3  IN-LINE CLIP  (2) 350kcmil-#4  64033  64033R  4 
    1  BOX  Cu**  64061  64061R  3  275 
    3  IN-LINE CLIP  (2) 350kcmil-#6  64063  64063R  4     
H
H
    1  BOX  Al/Cu  6631  6631R  5  500 
  600  3  IN-LINE CLIP  (2) 500kcmil-#4  6633  6633R  6 
 PHENOLIC 
 INSULATOR  1  BOX  Cu**  6661  6661R  5  375 
    3  IN-LINE CLIP  (2) 500kcmil-#4  6663  6663R  6
* Not UL Listed or CSA Certified 
** Fuse blocks have copper box connectors and clips and are for copper wires only. These are specifically designed with the same 
 coefficient of expansion as copper wire for improved heat cycling and meet or exceed OEM “no aluminum” specifications.
H 27
H 27