Siemens I-T-E Sensitrip MD Series Information And Instruction Manual page 28

I-T-E Handle Blocking Device (MN6BL)
General
The handle blocking device, MN6BL, is provided to permit
blocking the toggle handle of an MD and ND-Frame circuit
breaker in the OFF position. The device can be field modified
to permit blocking of the handle in the ON position.
Installation of Handle Blocking Device
A. Turn power off supplying circuit breaker
B. Turn circuit breaker off.
C. Loosen the two screws (1) (#10-32 x 3/8 in.) so that the
blocking device can be positioned and fully seated over
the toggle handle, as shown in Figure 1.
Figure 1
2 6
D. With a screwdriver, turn the screws so they enter the
blind holes molded in each side of the toggle handle.
Tighten the two screws evenly so that when they engage
the bottom of the blind holes, they project an equal
distance of .094 in. (Figure 2) above the tapped surface.
Do not over torque. Maximum torque 2 in. Ib.
Figure 2
Modification and Use for Blocking the Handle ON
The lip of the blocking device (2) (Figure 1) is undercut so that
a short section can be removed. To modify the device for
blocking a handle ON, snap off this removable tab and
discard.
A. Turn power off supplying circuit breaker
B. Turn circuit breaker on.
C. Follow installation procedures, Steps C and D, of "Instal-
lation Handle Blocking Device."