A refrigerator appliance comprising: a cabinet having a temperature-controlled compartment defined therein; a shelf ladder disposed at least partially in the temperature-controlled compartment and providing a plurality of shelf mounting positions, the shelf ladder comprising an electrical bus including first, second, and third conductors (306, 400, 500); and a first adjustable shelf carrying a first lighting device, the first adjustable shelf being removably mountable on the shelf ladder in one of the plurality of shelf mounting positions such that the first lighting device is electrically coupled to the electrical bus; characterized in that: the shelf ladder comprises a plurality of slots providing the plurality of shelf mounting positions for the first adjustable shelf; the first adjustable shelf includes a mounting brackets which includes a first tab carrying one or more conductors configured to engage at least one of the plurality of slots and contact the electrical bus; the three conductors (306, 400, 500) of the electrical bus are supported behind the shelf ladder and are accessible through one or more of the slots but are otherwise shielded by a face of the shelf ladder, and the electrical bus and is configured to supply power at a first current level and at a second current level by the second conductor being configured to supply power at the first current level when electrically coupled to the first conductor via a conductor of the first tab and the third conductor being configured to supply power at the second current level when electrically coupled to the first conductor via a conductor of the first tab. a cabinet having a temperature-controlled compartment defined therein; a shelf ladder disposed at least partially in the temperature-controlled compartment and providing a plurality of shelf mounting positions, the shelf ladder comprising an electrical bus including first, second, and third conductors (306, 400, 500); and a first adjustable shelf carrying a first lighting device, the first adjustable shelf being removably mountable on the shelf ladder in one of the plurality of shelf mounting positions such that the first lighting device is electrically coupled to the electrical bus; characterized in that: the shelf ladder comprises a plurality of slots providing the plurality of shelf mounting positions for the first adjustable shelf; the first adjustable shelf includes a mounting brackets which includes a first tab carrying one or more conductors configured to engage at least one of the plurality of slots and contact the electrical bus; the three conductors (306, 400, 500) of the electrical bus are supported behind the shelf ladder and are accessible through one or more of the slots but are otherwise shielded by a face of the shelf ladder, and the electrical bus and is configured to supply power at a first current level and at a second current level by the second conductor being configured to supply power at the first current level when electrically coupled to the first conductor via a conductor of the first tab and the third conductor being configured to supply power at the second current level when electrically coupled to the first conductor via a conductor of the first tab. the shelf ladder comprises a plurality of slots providing the plurality of shelf mounting positions for the first adjustable shelf; the first adjustable shelf includes a mounting brackets which includes a first tab carrying one or more conductors configured to engage at least one of the plurality of slots and contact the electrical bus; the three conductors (306, 400, 500) of the electrical bus are supported behind the shelf ladder and are accessible through one or more of the slots but are otherwise shielded by a face of the shelf ladder, and the electrical bus and is configured to supply power at a first current level and at a second current level by the second conductor being configured to supply power at the first current level when electrically coupled to the first conductor via a conductor of the first tab and the third conductor being configured to supply power at the second current level when electrically coupled to the first conductor via a conductor of the first tab.