Although the characteristics of current-limiting fuses are represented in peak let-thru charts, peak let-thru tables are easier to use.

Based on peak let-thru charts, the tables reflect fuse tests at 15% power factor at rated voltage, with prospective fault currents as high as 200,000 amperes. At each prospective fault current, let-thru data is given in two forms—I_RMS and I_p.

Where I_RMS is the apparent RMS symmetrical current and I_p is the maximum peak instantaneous current passed by the fuse, the l_p let-thru current is 2.3 times IRMS. This relationship exists between peak current and RMS available current under worst-case test conditions (i.e., closing angle of 0° at 15% power factor).

Using let-thru tables saves time and reduces the possibility of errors. The tables are also helpful when comparing the current-limiting capability of various fuses.

Click on the fuse name to view its peak let-thru table: Amp-Trap 2000® A4BQ Class L Fuse Amp-Trap 2000® AJT Class J Fuse Amp-Trap 2000® A6D Class RK-1 Fuse