Complex sentence: With Panel having no such restriction, its dimensions were determined solely by the needs of the switch, and the design of the exchange, as the driving electric motor can be made as large as is necessary to move the switch elements.
Split into simpler sentences: With Panel having no such restriction, its dimensions were determined solely by the needs of the switch, and the design of the exchange. The driving electric motor can be made as large as is necessary to move the switch elements.