Rockwell Automation 2361 Armature SCR Replacement (R, S-Frames) - Manual (Page 3)

Armature SCR Replacement (for 1250 and 1650A 1395 DC Drives) 3
Publication 2361-5.25 - July 1998
Preliminary Steps Before replacing the heatsink assembly, shut off the drive power, wait
five minutes for the voltage to discharge, open the bridge bay door,
and remove all Lexan™ guards shielding the heatsink assemblies.
Removing the Assembly 1. Using a voltmeter, test the voltage across the three phases, then
across the heatsink assembly components (including the SCRs).
2. Unplug the thermoswitch connector (upper assemblies only).
Note: Unplug thermoswitch connectors for any other assemblies
if they are in the way.
3. Unplug the gate lead connector from J1 on each armature-pulse
transformer board. (For SD3100 drives, disconnect the pulse-
gate amplifier boards.)
Note: Unplug gate lead connectors for any other assemblies if
they are in the way.
4. Remove the two fuses from the front of the assembly.
5. Remove the mounting bolts from the top and bottom of the
assembly.
6. Lift the heatsink assembly out of the drive.
!
ATTENTION: If there is any voltage present, remove
the source of the voltage and check for voltages again
before proceeding to the next step.
!
ATTENTION: Heatsink assemblies weight 60-75 lbs
each. Take the necessary precautions (adhere to your
company procedures for material handling) before
lifting to avoid injury and equipment damage.