Power Bus Splicing of 2500 A Bus with 100,000 A Short Circuit Rating

This section provides instructions for splicing the power bus of one section with 2500 A bus braced for 100,000 A to the power bus of another section of the same type. Splicing material is captive on the integral splice assembly unless the section is equipped with offset bus.

DANGER

Hazard of Electric Shock, Explosion, or Arc Flash Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, NOM-029-STPS-2011, or CSA Z462. This equipment must only be installed and serviced by qualified electrical personnel. Turn off all power supplying this equipment before working on or inside equipment. Always use a properly rated voltage sensing device to confirm power is off. Replace all devices, doors, and covers before turning on power to this equipment. Failure to follow these instructions will result in death or serious injury.

To splice the power bus, follow these steps:

1. Turn off all power supplying this equipment before working on or inside the equipment, and follow lockout/tagout procedures. Always use a properly rated voltage sensing device to confirm the power is off.

2. Remove the horizontal wireway covers and slide the horizontal bus barriers to gain access to the captive splice connectors (see Wireway Covers Removed and Horizontal Bus Barriers Open). See Appendix A—Removal and Installation of Horizontal Bus Barrier Panels for the steps for removing horizontal bus barriers.

   NOTE: On the integral splice bar assembly, located on the left side of each phase bus, the number of splice bars used on each phase is one greater than the number of main horizontal bus bars. Splice bars are held captive on the horizontal bus by a splice bar carrier assembly. The rear of the carrier assembly includes captive nuts (see Wireway Covers Removed and Horizontal Bus Barriers Open).

   Wireway Covers Removed and Horizontal Bus Barriers Open

   

3. Remove all four bolts from each splice assembly (see Remove the Bolts from the Splice Assembly).

   Remove the Bolts from the Splice Assembly

   

4. Slide the splice assembly to the left until the two left holes are in line with the corresponding holes in the horizontal bus on the left section (see Align the Splice and Bus Holes).

   Align the Splice and Bus Holes

   

5. Reinstall all four bolts through the splice assembly and into the horizontal bus (see Insert the Splice Bolts); make sure the original conical washers are reinstalled with the concave side facing the splice bus (see Place a Conical Washer Under the Bolt Head).

   Insert the Splice Bolts

   

   Place a Conical Washer Under the Bolt Head

   

6. Torque all bolts on both ends to 31–32 lb-ft (41.87–43.22 Nüm). See Torque All Bolts.

   Torque All Bolts

   

7. Repeat Steps 2–6 for all phases and the neutral bus (if supplied).

8. Before energizing the equipment, replace all covers and barriers.