Final answer:
A closed three-phase bank requires a single transformer and has a higher capacity compared to an open three-phase bank.
Step-by-step explanation:
The statement in the question is True. A closed three-phase bank requires a single transformer to supply three-phase power, whereas an open three-phase bank requires multiple transformers. Additionally, the capacity of the bank, or the amount of power it can handle, is different for closed and open banks. Closed banks typically have a higher capacity compared to open banks.