These requirements cover unit coolers intended for use in refrigerators@ freezers@ refrigerated warehouses@ walk-in coolers@ and the like. They are designed for connection to alternating current (ac) circuits rated not more than 600 volts. These requirements do not apply to fan-coil units intended for comfort cooling@ heating@ or both@ or to other air-conditioning equipment or components covered by individual requirements. Requirements for installation of unit coolers are included in the National Electrical Code@ NFPA 70@ and the Safety Standard for Refrigeration Systems@ ASHRAE Standard 15.