Type of Open Motor Enclosure/ Description General Purpose Open Motors (GPO) A General Purpose Open Motor (GPO) has ventilation openings in the end shields and main frame that allow external air to circulate through the motor cooling its internal parts. Opening location is unrestricted.
Open motor Enclosures function best in relatively clean and dry indoor areas. Open Drip Proof Open Drip-Proof (ODP) motor enclosures have vents in the end shields and main frame similar to an open enclosure. The vents are located near the bottom of the frame to prevent drops of liquid or solid particles from falling into the motor.
Open Drip-Proof motors are intended for use in reasonably dry, clean, and well-ventilated indoor settings. These motors tolerate a certain degree of moisture; however, they require a water-repellent cover that does NOT restrict the airflow necessary for cooling the motor (when used outdoors).
Open Splash Proof An Open Splash-Proof Motor (OPS) has ventilation openings designed to prohibit drops of liquid or solid particles coming towards the motor at any angle greater than 100° from entering the motor enclosure. OSP motors are intended for use in reasonably dry, clean, and well-ventilated indoor settings. When used outdoors, they require a water-repellent cover that does NOT restrict the airflow necessary for cooling the motor.