28
Rockwell Automation Publication 1512A-UM101B-EN-P - December 2021
Chapter 3 Installation – Arc-Resistant
Opening the Medium Voltage Door
A medium voltage door is shown in
1. Electrically open the contactor by pressing the STOP button on the
starter or at the remote control location.
2. Move the isolation switch handle to the OFF position.
3. Turn the black release handle for the upper right-hand MV door, counter-
clockwise 90°(to a 3 o’clock position). Only rotate the arc latching handle
when the door locking bolts are tightened (see
). The arc
latching-mechanism can be damaged by forcing the arc latching handle.
4. Unscrew the locking 3/8-1.75 bolts for the upper right-hand MV door.
5. Swing open the door that is now released.
6. Turn the black release handle, for the lower right-hand MV door,
counter-clockwise 90°(to a 3 o’clock position).
7. Remove the 3/8-1.75 bolts for the lower right-hand MV door.
8. Swing open the door that is now released.
9. Reverse the procedure to close the door. Tighten the 3/8-1.75 door lock-
bolts by hand until threads are engaged.
10. Verify all four 3/8-1.75 door locking bolts, on the right-hand side of the
MV doors, are in place and tightened until there is no gap between the
side sheet flange and door-locking bolt collar. DO NOT CROSSTHREAD
OR OVER TIGHTEN.
11. Turn all black release handles counterclockwise 90°(to a 3 o’clock
position). Failure to place the black handles in this position render the
cabinet arc resistant capabilities ineffective.
IMPORTANT
The medium voltage door has its own isolation switch handle and
interlocking safeguards. The low voltage panel compartment and
power cell are separated by an isolation barrier.
IMPORTANT
Failure to follow the MV door opening procedure could damage or
jam the mechanical door interlocks. This could result in the
mechanical interlocks not operating as intended and could result
in the door becoming jammed in the closed position.
On all ArcShield starters, the sticker in
is
attached to each door for your reference.
