Powered armour is, in essence, a mech the same scale as the pilot. The pilot climbs into and wears the powered armour as opposed to sitting in a cockpit piloting it. It functions like a mech, with a few fundamental changes:
So, a character with unarmoured toughness 9/3 and strength 3 wearing a suit of powered armour with strength 5, aluminum chassis (+3), and cerametal plate armour (+9) would in total have 18/12 toughness, as the character uses the powered armour€s armour bonus (but not chassis bonus) and his own endurance. Attacks against a character in powered armour threaten to wound the pilot directly. Neither the character€s own mass nor the mass of the vehicle€s chassis are added to encumbrance. Suits of powered armour never have multiple crew or passengers, except possibly in the case of onboard AI acting as an ECO, engineer, or even gunner.