Rockwell Automation 20D Power Module/SCR Replacement - Frame 6 - Manual (Page 2)

2
SCR Replacement
A. Locate SCR to be replaced. Note cable placement and
disconnect Gate Leads.
B. Disconnect the “SCR+” and “SCR–” cables. Remove
the SCR Bus Bars and Snubber Board.
C. Disconnect the “R,” “S” or “T” cable from the SCR
being replaced.
D. Remove the SCR by taking the appropriate screws out.
E. Thoroughly clean the SCR mounting surface. Apply a
thin coating of the supplied thermal grease to the new
SCR. Install with the supplied screws and tighten
using the sequence below.
F. Replace the Gate Leads and verify correct lead
placement. Note: Placement is the same for all SCR’s.
G. Re-assemble in reverse order. Tighten bus bar screws
to:
125-150 HP 5.6
±0.8 N-m (50 ±8.0 lbf.-in.)
200 HP 11
±1.6 N-m (95 ±15.0 lbf.-in.)
Tighten Snubber Board screws to 1.7
±0.4 N-m (15
±4.0 lbf.-in.).
H. If no further replacement is needed, re-assemble drive.
Tighten sheet metal screws to 3.2 N-m (28 lbf.-in.).
Brake IGBT Replacement
A. Locate Brake IGBT (see photo). Note cable placement
and disconnect cables/leads. Retain Module.
B. Remove the IGBT by taking out the four screws.
C. Thoroughly clean the IGBT mounting surface. Apply a
thin coating of the supplied thermal grease to the new
IGBT. Secure with the supplied screws and tighten
using the following sequence.
4
Gate Leads
SCR Bus
Bars
Snubber
Board Brake IGBT
(Not on All drives)
Module
125-150 HP Shown
1
4 2
3
First Sequence: 0.7 ±0.2 N-m (6.0 ±2.0 lbf.-in.)
Final Sequence: 5.0 ±0.7 N-m (44 ±7.0 lbf.-in.)
200 HP SCR Torque Sequence
1 2
First Sequence: 0.7 ±0.2 N-m (6.0 ±2.0 lbf.-in.)
Final Sequence: 6.0 ±0.9 N-m (53 ±8.0 lbf.-in.)
125-150 HP SCR Torque Sequence
R
S
T
“T” Lead from “X2”
Lead Assembly “T” Lead from “X3”
Lead Assembly