Illustration 1 | g01272800 |
Maintenance Bypass Cabinet - Left View (1) MBP Left Panel (2) Circuit Breaker (MBP) (3) Output Bus Bar (Phase C) (4) Output Bus Bar (Phase B) (5) Output Bus Bar (Phase A) (6) Input Cable Landing (Phase C) (7) Input Cable Landing (Phase B) (8) Input Cable Landing (Phase A) (9) Cable Landing (Ground) |
There are four tin-coated copper input cable landings in the Maintenance Bypass Cabinet. There is one landing for each phase of the three-phase power supply and one for the ground. Refer to Illustration 5 for cable landing locations.
The input cable landings accommodate 500 kcmil to 750 kcmil cable.
The installer will punch the appropriate hole pattern for trade size conduit depending on the size and number of input cables.
Each of the three phase cable landings has a wire attached to the back. The wire runs to the fuse block. Then, the wire runs up to the transformers. These wires provide power through the transformers to the boards on the left panel.
Cable Landing Phase Bar Removal
- Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Maintenance Bypass Cabinet)" in order to de-energize the system and gain access to internal components.
- Disconnect the utility input cables from the cable landing.
- Disconnect the wire to the transformer that is connected to the back of the cable landing.
- Loosen the back three bolts that connect the landing to the cabinet.
- Loosen the front three bolts that connect the landing to the vertical bus bar leading into the circuit breaker.
- Remove the cable landing.
Cable Landing Phase Bar Installation
- Place the input cable landing in position.
- Attach the front landing to the vertical bus bar that comes from the circuit breaker. Insert the three bolts from the back side.
- Attach the washers and the nuts in the order that is indicated in Illustration 2.
Note: In all cases, the side of the belleville washer that curves inward should be placed facing the bus bar.
Illustration 2 | g01271171 |
(20) Nut (21) Belleville Washer (22) Grade 8 Coated Steel Washer (23) Bus Bars (24) Bolt |
- Insert three bolts and three washers at the back of the cable landing. Place bolt and washer through the cable landing, a red insulating spacer (11) and into the back of the cabinet.
Illustration 3 | g01337718 |
- Attach the wires that lead to the fuse block and supply power to the transformers to a peg at the back of the cable landing.
Show/hide table
Table 1 Wire Color     Phase     Brown     A     Orange     B     Yellow     C    
- Attach the utility input cables to the bus bar.
Refer to Illustration 7.
Illustration 4 | g01271424 |
(60) Nut (61) Belleville Washer (62) Grade 8 Coated Steel Washer (63) Bus Bars (64) Bolt (65) Cable Lug |
- Tighten all front bus bar nuts to 150 N·m (110 lb ft).
- Tighten utility input cable lugs to appropriate specifications.
Note: Always tighten the hex nut, not the bolt.
Cable Landing Ground Bar Removal
- Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Maintenance Bypass Cabinet)" in order to de-energize the system and gain access to internal components.
- Disconnect the utility input cables from the ground cable landing that is located at the top, right side of the cabinet.
- Loosen the back two bolts that connect the landing to the cabinet frame.
- Loosen the front two bolts that connect the ground landing to the right side transformer panel.
- Remove the cable landing.
Cable Landing Ground Bar Installation
- Place the ground cable landing in position.
Refer to Illustration 5.
Illustration 5 | g01272800 |
Maintenance Bypass Cabinet - Left View (1) MBP Left Panel (2) Circuit Breaker (MBP) (3) Output Bus Bar (Phase C) (4) Output Bus Bar (Phase B) (5) Output Bus Bar (Phase A) (6) Input Cable Landing (Phase C) (7) Input Cable Landing (Phase B) (8) Input Cable Landing (Phase A) (9) Cable Landing (Ground) |
- Attach the front of the landing to the right side transformer panel by inserting two bolts, each with one steel washer and one split washer, from the back side.
- Attach the rear of the landing with two bolts, through the right side of the cabinet frame, according to the diagram in Illustration 6.
Illustration 6 | g01273654 |
(60) Nut (62) Steel Washer (63) Bus Bars (64) Bolt (66) Split Washer |
- Attach the utility input ground cables to the bus bar according to the diagram in Illustration 7.
Note: In all cases, the side of the belleville washer that curves inward should be placed facing the bus bar.
Illustration 7 | g01271424 |
(60) Nut (61) Belleville Washer (62) Grade 8 Coated Steel Washer (63) Bus Bars (64) Bolt (65) Cable Lug |
- Tighten all ground bus bar nuts to 150 N·m (110 lb ft).
- Tighten the input ground cable nuts to appropriate specifications.
Note: Always tighten the hex nut, not the bolt.