Fuse Description and Manufacturer Cross Reference
Below is a summary table of the main branch fusing and control fuses used in Shift Controls temperature control panels and equivalent fuses from the recommended manufactures. Always replace fuses with the same type, size, and speed. This is to ensure the safety of personnel, protect equipment, and maintain the Short Circuit Current Rating of the panel. If you have any questions regarding the fusing in the panels, feel free to contact our knowledgeable staff.
Fuse Manufacturer Cross Reference Table
| Manufacturer Equivalent Fuse | ||||||
| Fuse Description | Fuse Type | Speed | Voltage | Edison | Bussmann | Littlefuse |
| ISPA Series Fuses | ||||||
| Supplementary, Control Circuit (F2) |
5x20 mm 1 Amp |
Fast-Acting | 250VAC | GMA | GMA | 235 |
| Main Power Branch Fusing (F1) | Class CC 1-20 Amp |
Fast-Acting | 600VAC | HCLR | KTK-R | KLKR |
| IFPA Series Fuses | ||||||
| Supplementary, Control Circuit |
5x20 mm 1 Amp |
Fast-Acting | 250VAC | GMA | GMA | 235 |
| Control Transformer, Primary (480VAC models) |
Midget Class 1 Amp |
Time-Delay | 500VAC | MEQ | FNQ | FLQ |
| Control Transformer, Secondary (480VAC models) |
Midget Class 1 Amp |
Fast-Acting | 250VAC | MOL | BAF/BAN | BLF |
| Main Power Branch Fusing | Class J Amp Varies |
High Speed | 600VAC | JHL | DFJ | N/A |
Fuse Reducer Application Guide
IFPA Series control panels use Class J current limiting branch fuses for the main fuse protection. Class J fuses are different physical dimensions based on the fuse current rating. Class J fuses rated 1-30 Amp, 35-60A, and 70-100A are 3 different physical dimensions. For example, a fuse reducer is required for using a 60A fuse in 100A rated fused disconnect holder.
Fuse Current Rating Reducer Requirement Table
| Power Circuit Fuse Rating | |||||
| 1 - 30A Fuse | 35 - 60A Fuse | 70 - 100A Fuse | |||
| Shift Controls Model | Fuse Disconnect Holder Rating | Max Fuse Size | Fuse Reducer Model Required | ||
| ISPA-120-1P-15A | 30A, Class CC | 20A | None Required | N/A | N/A |
| IFPA-XXX-3P-24A | 30A, Class J | 30A | None Required | N/A | N/A |
| IFPA-XXX-1P-35A | 60A, Class J | 45A | Littlefuse LRUJ63 | None Required | N/A |
| IFPA-XXX-3P-64A | 100A, Class J | 80A | N/A | Littlefuse LRUJ16 | None Required |
Note: -XXX- in Model Number represents the control panel voltage.
Fuse Sizing Diagrams and Tables
Below are the fuse sizing diagrams and tables for Shift Controls ISPA and IFPA series temperature control panels. Find the model number of your panel and lookup either your heater full load current (top x-axis) or the full load power (bottom x-axes). Next, determine the correct size of fuse for your application, by finding the fuse size box which intersects on the y-axis. If your heater is between fuse sizes, it is typically better to use the larger size.
Never exceed the maximum allowable fuse size for your control panel. Always use correctly sized fuses, rated for the speed and voltage of the application. Reference the control panel’s wiring diagram for more information on recommended fuse sizes for your control panel.
Fuse Sizing Diagram (ISPA-120-1P-15A)
Fuse Sizing Table (ISPA-120-1P-15A)
| Fuse Size | ||||||||||||||
| 2A | 2.5A | 3A | 3.5A | 4A | 5A | 6A | 8A | 10A | 12A | 15A | 17.5A | 20A | ||
| Power, Watts |
Min | 150 | 188 | 225 | 263 | 300 | 375 | 450 | 600 | 750 | 900 | 1125 | 1313 | 1500 |
| Max | 192 | 240 | 288 | 336 | 384 | 480 | 576 | 768 | 960 | 1152 | 1440 | 1680 | 1800 | |
| FLA, Amps |
Min | 1.25 | 1.56 | 1.88 | 2.19 | 2.50 | 3.13 | 3.75 | 5.00 | 6.25 | 7.50 | 9.38 | 10.94 | 12.50 |
| Max | 1.60 | 2.00 | 2.40 | 2.80 | 3.20 | 4.00 | 4.80 | 6.40 | 8.00 | 9.60 | 12.0 | 14.0 | 15.0 | |
Fuse Sizing Diagram (IFPA-120-1P-35A)
Fuse Sizing Table (IFPA-120-1P-35A)
| Fuse Size | ||||||||||||||
| Littlefuse® LRUJ63 Fuse Reducers Required for 1-30A Fuses | No Fuse Reducers | |||||||||||||
| 5A | 6A | 8A | 10A | 12A | 15A | 17.5A | 20A | 25A | 30A | 35A | 40A | 45A | ||
| Power, kW |
Min | 0.38 | 0.45 | 0.60 | 0.75 | 0.90 | 1.13 | 1.31 | 1.50 | 1.88 | 2.25 | 2.63 | 3.00 | 3.38 |
| Max | 0.48 | 0.58 | 0.77 | 0.96 | 1.15 | 1.44 | 1.68 | 1.92 | 2.40 | 2.88 | 3.36 | 3.84 | 4.20 | |
| FLA, Amps |
Min | 3.13 | 3.75 | 5.00 | 6.25 | 7.50 | 9.38 | 10.9 | 12.5 | 15.6 | 18.8 | 21.9 | 25.0 | 28.1 |
| Max | 4.00 | 4.80 | 6.40 | 8.00 | 9.60 | 12.0 | 14.0 | 16.0 | 20.0 | 24.0 | 28.0 | 32.0 | 35.0 | |
Fuse Sizing Diagram (IFPA-208-1P-35A)
Fuse Sizing Table (IFPA-208-1P-35A)
| Fuse Size | ||||||||||||||
| Littlefuse® LRUJ63 Fuse Reducers Required for 1-30A Fuses | No Fuse Reducers | |||||||||||||
| 5A | 6A | 8A | 10A | 12A | 15A | 17.5A | 20A | 25A | 30A | 35A | 40A | 45A | ||
| Power, kW |
Min | 0.65 | 0.78 | 1.04 | 1.30 | 1.56 | 1.95 | 2.28 | 2.60 | 3.25 | 3.90 | 4.55 | 5.20 | 5.85 |
| Max | 0.83 | 1.00 | 1.33 | 1.66 | 2.00 | 2.50 | 2.91 | 3.33 | 4.16 | 4.99 | 5.82 | 6.66 | 7.28 | |
| FLA, Amps |
Min | 3.13 | 3.75 | 5.00 | 6.25 | 7.50 | 9.38 | 10.9 | 12.5 | 15.6 | 18.8 | 21.9 | 25.0 | 28.1 |
| Max | 4.00 | 4.80 | 6.40 | 8.00 | 9.60 | 12.0 | 14.0 | 16.0 | 20.0 | 24.0 | 28.0 | 32.0 | 35.0 | |
Fuse Sizing Diagram (IFPA-240-1P-35A)
Fuse Sizing Table (IFPA-240-1P-35A)
| Fuse Size | ||||||||||||||
| Littlefuse® LRUJ63 Fuse Reducers Required for 1-30A Fuses | No Fuse Reducers | |||||||||||||
| 5A | 6A | 8A | 10A | 12A | 15A | 17.5A | 20A | 25A | 30A | 35A | 40A | 45A | ||
| Power, kW |
Min | 0.75 | 0.90 | 1.20 | 1.50 | 1.80 | 2.25 | 2.63 | 3.00 | 3.75 | 4.50 | 5.25 | 6.00 | 6.75 |
| Max | 0.96 | 1.15 | 1.54 | 1.92 | 2.30 | 2.88 | 3.36 | 3.84 | 4.80 | 5.76 | 6.72 | 7.68 | 8.40 | |
| FLA, Amps |
Min | 3.13 | 3.75 | 5.00 | 6.25 | 7.50 | 9.38 | 10.9 | 12.5 | 15.6 | 18.8 | 21.9 | 25.0 | 28.1 |
| Max | 4.00 | 4.80 | 6.40 | 8.00 | 9.60 | 12.0 | 14.0 | 16.0 | 20.0 | 24.0 | 28.0 | 32.0 | 35.0 | |
Fuse Sizing Diagram (IFPA-480-1P-35A)
Fuse Sizing Table (IFPA-480-1P-35A)
| Fuse Size | ||||||||||||||
| Littlefuse® LRUJ63 Fuse Reducers Required for 1-30A Fuses | No Fuse Reducers | |||||||||||||
| 5A | 6A | 8A | 10A | 12A | 15A | 17.5A | 20A | 25A | 30A | 35A | 40A | 45A | ||
| Power, kW |
Min | 1.50 | 1.80 | 2.40 | 3.00 | 3.60 | 4.50 | 5.25 | 6.00 | 7.50 | 9.00 | 10.5 | 12.0 | 13.5 |
| Max | 1.92 | 2.30 | 3.07 | 3.84 | 4.61 | 5.76 | 6.72 | 7.68 | 9.60 | 11.5 | 13.4 | 15.4 | 16.8 | |
| FLA, Amps |
Min | 3.13 | 3.75 | 5.00 | 6.25 | 7.50 | 9.38 | 10.9 | 12.5 | 15.6 | 18.8 | 21.9 | 25.0 | 28.1 |
| Max | 4.00 | 4.80 | 6.40 | 8.00 | 9.60 | 12.0 | 14.0 | 16.0 | 20.0 | 24.0 | 28.0 | 32.0 | 35.0 | |
Fuse Sizing Diagram (IFPA-208-3P-24A)
Fuse Sizing Table (IFPA-208-3P-24A)
| Fuse Size | |||||||||||
| 5A | 6A | 8A | 10A | 12A | 15A | 17.5A | 20A | 25A | 30A | ||
| Power, kW |
Min | 1.13 | 1.35 | 1.80 | 2.25 | 2.70 | 3.38 | 3.94 | 4.50 | 5.63 | 6.75 |
| Max | 1.44 | 1.73 | 2.31 | 2.88 | 3.46 | 4.32 | 5.04 | 5.76 | 7.21 | 8.65 | |
| FLA, Amps |
Min | 3.13 | 3.75 | 5.00 | 6.25 | 7.50 | 9.38 | 10.9 | 12.5 | 15.6 | 18.8 |
| Max | 4.00 | 4.80 | 6.40 | 8.00 | 9.60 | 12.0 | 14.0 | 16.0 | 20.0 | 24.0 | |
Fuse Sizing Diagram (IFPA-480-3P-24A)
Fuse Sizing Table (IFPA-480-3P-24A)
| Fuse Size | |||||||||||
| 5A | 6A | 8A | 10A | 12A | 15A | 17.5A | 20A | 25A | 30A | ||
| Power, kW |
Min | 2.60 | 3.12 | 4.16 | 5.20 | 6.24 | 7.79 | 9.09 | 10.4 | 13.0 | 15.6 |
| Max | 3.33 | 3.99 | 5.32 | 6.65 | 7.98 | 9.98 | 11.6 | 13.3 | 16.6 | 20.0 | |
| FLA, Amps |
Min | 3.13 | 3.75 | 5.00 | 6.25 | 7.50 | 9.38 | 10.9 | 12.5 | 15.6 | 18.8 |
| Max | 4.00 | 4.80 | 6.40 | 8.00 | 9.60 | 12.0 | 14.0 | 16.0 | 20.0 | 24.0 | |
Fuse Sizing Diagram (IFPA-208-3P-64A)
Fuse Sizing Table (IFPA-208-3P-64A)
| Fuse Size | ||||||||
| Littlefuse® LRUJ63 Fuse Reducers Required for 1-30A Fuses | No Fuse Reducers | |||||||
| 35A | 40A | 45A | 50A | 60A | 70A | 80A | ||
| Power, kW |
Min | 7.88 | 9.01 | 10.1 | 11.3 | 13.5 | 15.8 | 18.0 |
| Max | 10.1 | 11.5 | 13.0 | 14.4 | 17.3 | 20.2 | 23.1 | |
| FLA, Amps |
Min | 21.9 | 25.0 | 28.1 | 31.3 | 37.5 | 43.8 | 50.0 |
| Max | 28.0 | 32.0 | 36.0 | 40.0 | 48.0 | 56.0 | 64.0 | |
Fuse Sizing Diagram (IFPA-480-3P-64A)
Fuse Sizing Table (IFPA-480-3P-64A)
| Fuse Size | ||||||||
| Littlefuse® LRUJ63 Fuse Reducers Required for 1-30A Fuses | No Fuse Reducers | |||||||
| 35A | 40A | 45A | 50A | 60A | 70A | 80A | ||
| Power, kW |
Min | 18.2 | 20.8 | 23.4 | 26.0 | 31.2 | 36.4 | 41.6 |
| Max | 23.3 | 26.6 | 29.9 | 33.3 | 39.9 | 46.6 | 53.2 | |
| FLA, Amps |
Min | 21.9 | 25.0 | 28.1 | 31.3 | 37.5 | 43.8 | 50.0 |
| Max | 28.0 | 32.0 | 36.0 | 40.0 | 48.0 | 56.0 | 64.0 | |
- Brad Kettler
