The type SF switch-fuse combination is ideally suited for providing circuit protection while the recloser is having maintenance performed on it, and when used in conjunction with one of Southern States hookstick operated switches they also provide isolation of the recloser for maintenance. The SF consists of Southern States type PBO hookstick operated switch and Southern States type BP power fuse (on types SF50 and SF51) or Southern States type HPA power fuse (on types SF52 and SF53).
If the circuit is important enough to have protection via a recloser during normal service conditions isn't it important enough to still have protection during recloser maintenance? Choose the SF switch-fuse combination, protection and isolation in one compact package.