The Mega® type fuse is a very popular choice for high-current / low-voltage applications. Nominal currents can range from 100A to 300A @ 32VDC.
Bussmann, Littelfuse, and of course OptiFuse all manufacture these "bolt-down" type fuses.
Bussmann and Littelfuse manufacture their fuses (AMG and MEGA®) with an opaque black plastic body that makes it impossible to see the element inside the fuse.
Bussmann - AMG
Littelfuse - MEGA®
OptiFuse, on the other hand, manufacturers its equivalent fuse (MGGA) with a tinted clear plastic body allowing easy viewing of the fuse link.
OptiFuse - MGGA
Ok...now you’re faced with an open fuse...so now you need to determine which fuse is the bad one?...if you happen to have a Bussmann or Littelfuse part...you had better have a continuity tester or ohmmeter handy or you’re out of luck...
With the OptiFuse fuse...simply hold it up to the light and take a look at the element...a pretty simple solution to a pretty simple problem
Thank you very much for your continued support of OptiFuse as we try to simplify circuit protection...
* - MEGA® fuse is a registered trademark of Littelfuse, Inc