The rack must use grounding-type power cords. For example, Oracle's Sun Rack II has three-wire, grounding-type power cords. Always connect the cords to grounded power outlets. Because different grounding methods are used, depending on location, check the grounding type, and refer to documentation, such as local electrical codes, for the correct grounding method. Ensure that the facility administrator or qualified electrical engineer who verifies the grounding method for the building performs the grounding work.