S&C VacuFuse, Installation And Operation Manual

16    S&C Instruction Sheet 465-500

Operation

To Close:

 Pull the pull-ring of the yellow OPEN/CLOSE 

lever down firmly using the straight prong of the Talon 
tool or a distribution prong. The vacuum interrupter inside 
the VacuFuse interrupter will close, and the POSITION 
indicator will show the red target. See Figure 16. If the 
VacuFuse interrupter is inadvertently closed into a fault, 
the vacuum interrupter will trip open independently of any 
force still applied to OPEN/CLOSE lever.

To Reset the OPEN/CLOSE Lever After Manually 

Closing into Fault Current:

 If the transformer is manu-

ally closed into fault current, the VacuFuse interrupter 
will trip open in response, leaving the lever in the 

Closed

position when the vacuum interrupter is in the 

Open

position. The lever can be “reset” by operating it into the 

Open

 position while the vacuum interrupter is in the 

Open

 position.

Setting the MODE SELECTOR Lever

Before leaving the VacuFuse Self-Resetting Interrupter, 
verify the MODE SELECTOR lever is in the desired 
position. The MODE SELECTOR lever has two positions. 
Figure 17 shows the MODE SELECTOR lever up in the 

Auto

 mode position. Figure 18 on page 17 shows the 

MODE SELECTOR lever down in the 

NR

 (non-reclose) 

mode position.

Auto Mode

—In the 

Auto

 mode, the VacuFuse inter-

rupter will respond to fault current according to its preset 
TCC curve. The VacuFuse interrupter will perform one 
reclosing operation (two trip operations total) to lockout. 
The open interval between trip operations is user-specified 
and factory set between 0.5 and 5 seconds. 

The protection sequence reset time is a user-specified and 

factory-set interval between 30 seconds and 15 minutes. If a 
fault persists to the end of the protection sequence, the vac-
uum interrupter inside the VacuFuse interrupter will remain 
in the 

Open/Lockout

 state until manually closed. The 

VacuFuse Self-Resetting Interrupter will NOT drop out 
of the mounting and will remain upright in the cutout 
mounting.

The VacuFuse Self-Resetting Interrupter is in the 

Auto

mode when the curved label on the side of the VacuFuse 
interrupter’s housing is fully covered and the label on the 
bottom of the lever aligns with the label on the bottom 
of the VacuFuse interrupter’s housing. See Figure 17 and 
Figure 11 on page 14.

Figure 16. Closing the VacuFuse interrupter by pulling down on 
the OPEN/CLOSE lever. 

Figure 17. The MODE SELECTOR lever in the Auto mode 
position. 

MODE 

SELECTOR 

lever