Rockwell Automation 2361 Armature SCR Replacement (R, S-Frames) - Manual (Page 5)

Armature SCR Replacement (for 1250 and 1650A 1395 DC Drives) 5
Publication 2361-5.25 - July 1998
Use the following procedures to remove and replace each SCR.
Removing SCRs 1. Disconnect the SCR leads from the armature-pulse transformer
board terminals (not necessary for SD3100 drives).
2. Remove the two clamp nuts.
3. Pull apart the heatsinks and remove the SCR.
Replacing SCRs 1. Apply silicone oil to the contact surfaces of the new SCR.
2. Properly position the new SCR securely between the heatsinks.
3. Fit rollpins into the SCR indentations (take care not to damage
the SCR). The gate leads should extend out through the front of
the assembly to the armature-pulse transformer boards, as shown
in the heatsink assembly diagram on the previous page.
4. Fasten the two clamp nuts. Torque the clamp nuts to 10,000 lb-ft
(10 on the clamp indicator).
5. Connect the SCR leads to the armature-pulse transformer board
terminals. (For SD3100 drives, crimp connectors onto the gate
leads and plug the connectors onto the pulse-gate adapter boards.)
Verify all wiring.
!
ATTENTION: Ensure that the SCRs are installed with
the proper polarity (as shown in the following diagram).
Improper installation will result in damage to the power
bridge and may damage other externally connected
equipment.
SCR Polarity (Front View)
S
nubbe
rs
DC
H
e
at
si
nk
AC
H
ea
ts
in
k
AC
H
e
at
si
n
k
Red
White
1395 Drives SD3100 Drives