The ESP-OL style fan motors, primarily for refrigeration and HVAC condenser fan duty, represent the highest power outputs available in the effecient eccentric wound shaded pole design. The ESP design exhibits a higher electrical efficiency than the typical shaded pole motor.
The 4-pole unit bearing motors are available in three outputs – The ESP-OL50 rated at 50 watts (1/15 HP), the ESP-OL60 rated at 50 or 60 watts (1/12 HP), and the ESP-OL75 rated at 75 watts (1/10 HP). Standard performance tests reveal all models attain an electrical efficiency of 39% when tested at 1600 rpm.
The ESP-OL50 was originally designed to meet the need for a more powerful unit bearing fan motor for the refrigeration condensing unit manufacturing industry. The motor will operate without periodic service (oiling) over the full life span of a condensing unit system. This motor has been eminently successful as a quiet, cool running, long life performer.
Similarly, the ESP-OL60 and the ESP-OL75 motors have been introduced to the market where a more powerful motor is needed in order to increase the airflow in an application, or to operate over a wider range of voltage conditions. The ESP-OL60 is dimensionally interchangeable with the ESP-OL50, and is even more stable in low voltage conditions. The ESP-OL75 provides more power where a slightly larger fan is required to obtain the necessary airflow.
The ESP-OLs follow exactly the classic EM&S unit bearing design. They have the hardened steel shaft, cast iron bearing surface, hydrodynamic lubrication system, a massive oil supply and high concentricities resulting quiet running, long life performance.
The motors can be wound for 100, 115, 208, 230, and 460 volt duty to operate on 60 or 50 Hz. The direction of rotation is determined from the lead end.