Rockwell Automation 1512A MV Controllers, 400A One-High Cabinet, Standard and Arc-Resistant Enclosure - Manual (Page 69)

Rockwell Automation Publication 1512A-UM100F-EN-P - May 2013 61
Maintenance Chapter 5
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
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.
1. Once the auxiliaries have been adjusted, move the isolation switch handle
to the ON position.
2. Connect a device to indicate continuity 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.
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 58 ).
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.
ATTENTION: 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. Failure to
correctly set the auxiliary contacts may result in serious damage to the
controller and/or injury 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.
ATTENTION: This procedure may expose personnel to energized medium
voltage components. Whenever possible, lock out incoming power before
beginning this procedure. If you are unable to lock out incoming power, use the
appropriate protective equipment and work practices to avoid shock hazards.
Failure to do so may result in severe burns, injury or death.