For Lighting Panels, P1/P2/P3, what are the standard Ground Bar/Bus capabilities and options?

Wire size range of the EGK / ECGK / IGK / ICGK lug connections/holes:
(note:  The multiple combinations typically only apply when used as an equipment ground. 
If similar bar is used as a neutral bar, only one wire can be used in each hole.)

1. Connection count: (6) of #14-1/0 and (15) of #14-6 Connections (21 Holes total). (note: one Connection may be needed for incoming Ground Connection)
2. The Maximum wire size the standard ground accepts is: 1/0 in the Large Holes and #6 in the Smaller Holes.
3. Small Hole can accept: (1-2 wires) #14-12; (1 wire) #10; (1 wire) #8-#6.
4. The Large Hole can accept: (1-3 wires) #14-#10; (1 wire) #8; (1 wire) #6 - #4; (1 wire) #3-1/0. 
5. Max. connections if largest wire size is used:  (6 x 1) + (15 x 1) = 21
6. Max. connections if smallest wire size is used:  (6 x 3) + (15 x 2) = 48
7. Request for Ground Lug greater than 1/0 in Size requires a Special Modification in COMPAS when Line Item is entered (specify number of connections needed greater than 1/0) or Manual Line for Custom Ground (specify number of connections needed greater than 1/0).

EGK / ECGK / IGK / ICGK Installation Instructions:

Ground bus to be mounted in either left or right gutter with hardware provided. Applied torque ratings shall be 45-lbs-inch for three No. 10 AWG solid copper conductors in the large holes. For all other combinations of conductors, refer to the torque rating label on the panelboard.
Note: For IGK/ICGK, insure ground bar is attached to Glastic insulator with 2 screws before mounting insulator to enclosure.  Ground Bar mounts thru side holes oriented as shown in picture below.

This chart is on labels for P1, P2 and P3 Enclosures.

EGK  / ECGK kit parts:

IGK/ ICGK kit parts

See link below for Web Page where document can be downloaded: click here

Additionally, the factory can provide some custom solutions when needed. Contact Spartanburg Customer Support for more information.