Example 1 – Selection & Sizing of solar DC Fuse


Let’s consider a project with a two-string configuration. We have an array of 18 modules connected in series in a string.

System Configuration
Module Specifications


Step 1: Requirement of Overcurrent Protection Device

Requirement of overcurrent protection device (or a DC Fuse) is assessed by using below formula

[(Ns – 1) x Isc_mod] > [Imod_max_ocpr]

Putting values of parameters as provided in the problem :

[(Ns – 1) x Isc_mod] = [(2 – 1) x 12.28] = 12.28 A

Imod_max_ocpr = Max Series Fuse Rating = 20 A

Since, 12.28 A is less than 20 A, the above condition is not met.

Hence, there is no requirement of an Overcurrent device or a Solar DC Fuse in the system .


Leave a Reply

Your email address will not be published. Required fields are marked *

Let's Get Connected