Chart
Current-limiting fuse let-through vs SCCR chart
Visualize how current-limiting fuses can reduce downstream peak current and I2t exposure for equipment SCCR review.
Does not select a fuse, raise equipment SCCR, approve a control panel, or replace manufacturer combination ratings.
let through curve
Available fault current to let-through band
The curve concept shows why two devices with the same ampere rating can create different downstream stress.
Class and amp rating change the band.
Use calculated or utility-provided fault current.
Use manufacturer charts, not generic values.
A fuse alone does not relabel equipment.
Decision table
Show the relationship between available fault current, let-through current, and downstream equipment SCCR questions.
Scroll sideways to keep row labels aligned with hidden columns.
| Curve band | What it shows | Risk cue | Handoff |
|---|---|---|---|
| Prospective current | Unlimited available current level | Can exceed equipment rating | Fault-current margin calculator |
| Peak let-through | Current-limiting peak stress | Must use manufacturer chart | Fuse data sheet |
| I2t let-through | Thermal energy stress | Combination rating needed | SCCR guide |
| Downstream SCCR | Equipment withstand context | Label and listing govern | AIC/SCCR label table |
Notes
- Treat this chart as a planning and conversation aid only.
- Confirm current utility requirements, product markings, manufacturer instructions, and local authority requirements before field work.
- Use the linked calculator or table when the task needs project-specific arithmetic.
Source links
Open the underlying public sources before treating the chart as project guidance.