Square D PK9GTA Qo Equipment Ground Bar Assembly Brand: Square D. Part Number: PK9GTA. Square D QO Equipment Ground Bar Assembly, For Use with: QO Load Center and Type PK Circuit Breaker, 2-Screw, 14 to 10 AWG Copper, 12 to 10 AWG Aluminum Cable Size, 12-Circuit. Additional Description: SQD -PK9GTA LOAD CENTER EQUIPMENT GROUND BAR ASSY. Catalog Description: Panelboard accessory, NQ, ground bar kit, 12 circuits, 225A max..