In any case where a worker is provided with board or lodging by his employer, the deduction in respect thereof by the employer shall not exceed such amount as will reduce the worker’s wages calculated at the appropriate minimum rate by more than the cash value thereof as fixed by or under any Act, award, collective agreement, or agreement relating to the worker’s employment, or, if it is not so fixed, the deduction in respect thereof by the employer shall not exceed such amount as will reduce the worker’s wages (as so calculated) by more than 15 percent for board or by more than 5 percent for lodging.”