Rockwell Automation 1512B MV Controllers, 200/400A Two-High Cabinet, Standard and Arc-Resistant Enclosure - Manual (Page 74)

66 Rockwell Automation Publication 1500-UM055G-EN-P - May 2013
Chapter 5 Maintenance
6. Operate the handle several times, then recheck the 6.35 mm (0.25 in.)
clearance between the end of the cam groove and the follower pin for both
cams.
7. Verify that auxiliary contact ISb is closed when isolation switch is open.
Verify that ISb contact is open when isolation switch is closed.
Adjusting the Change-of-State Point
1. Once the auxiliaries have been adjusted, move the isolation switch handle
to the ON position.
2. Connect a conductivity measuring device across the closed auxiliary
contacts.
3. Slowly move the isolation switch handle towards the OFF position and
observe the point at which the movable isolation switch blades separate
from the incoming line stabs. The auxiliary contacts must change state
from the closed to open position before the isolation switch blades lose
contact with the incoming line stabs. This prevents the isolation switch
from being opened while the unit is energized and under load conditions.
4. If the auxiliaries do not change state before the isolation switch opens,
repeat the auxiliary contacts adjustment procedure (refer to Auxiliary
Contacts Inspection and Replacement on page 63 ).
Emergency Circumvention
Procedure for Power Cell
Entry The interlocking mechanism of the medium voltage starter is designed to
prohibit access to the power cell while the isolation switch handle is in the ON
position and the isolation switch is closed.
IMPORTANT This procedure sets the secondary electrical interlock. When properly adjusted,
the electrical interlock is designed to open the control power circuit before the
isolation switch opens as the handle is moved to the OFF position.
ATTENTION: The auxiliary contacts must be properly adjusted to avoid
opening the isolation switch under load conditions. Improper
adjustment may result in damage to the equipment and/or severe
burns, injury or death to personnel.
IMPORTANT The following procedure is intended to be used only when the isolation switch
cannot be opened as described in the Door Opening Procedure for either
standard or ArcShield enclosures.