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Routine Maintenance and Repair
8-5
590+ Series DC Digital Converter
In-Situ Replacement Procedure
1. Disconnect the relevant fuse microswitch assembly by unplugging the lead assembly from
the rear trunking.
2. Remove the M12 screw (A), and the 4 screws (F, G, H, I). Remove the CT plate and
handles.
3. Remove the relevant screws (B, C or D, E) and lift the fuse busbar assembly from the phase
assembly.
4. Replace the fuse on the busbar and re-connect the microswitch. Fully tighten the fuse to the
busbar.
5. Fit the fuse busbar assembly on to the phase assembly. Don’t fully tighten the screws yet.
6. Position the CT plate on top of the fuses. The slack in the fuse busbar assembly will allow
the fixing holes to be aligned. Insert the screws.
7. Fully tighten all screws (including those in 5 above).
8. Re-connect the fuse microswitches.
591+ 2Q Product (Non-Regenerative)
D
E
B
C
A
Phase Assembly
Current
Transformer
AC Incoming
Busbar
Fuse
CT Plate/Fuse
Fixing Screws
CT Plate/CT Boss
Fixing Screw
FRONT VIEW
Fuse Assy/Phase Assy
Fixing Screws
SIDE VIEW
Figure 8-2 591+ Fuse Replacement Diagram
IMPORTANT:
When re-assembling the unit, apply a `zinc-loaded’ jointing compound between the
fuses and busbars, and between the busbars and phase assemblies (BICC BX1 - SSD
Part No. EA466241)
Observe all tightening torque levels, refer to Chapter 11: “Technical Specifications” -
Fixing Types and Torques.
Bench-Top Replacement Procedure
Working on the relevant fuse assemblies:
1. Remove the M12 screw (A).
2. Release the two M12 screws (B, C) and remove the CT plate.
3. Remove the two M10 screws (D, E) fixing the fuse assembly to the phase assembly.
4. On the bench, replace the relevant fuse on the fuse assembly.