Remco's 41 range of shaded pole motors is particularly suitable for driving light to medium power fan applications.
They are produced both in 4 and 6 pole versions with outputs ranging from 8 to 80 watts. Generally the range is of single speed motors but there are available some multi-speed motors with 2 and 3 speeds. These are marked with /2 or /3 symbols in the motor identification code in the catalogue.
(As mentioned on the previous page there is one exception in the range which is a PSC motor, 41-4-38/5C, which offers five speeds in total.)
41 range shaded pole motors are suitable for a wide range of fan applications, both axial and centrifugal types. They are available both in Ventilated and Totally Enclosed bodies and may have single or double shaft extensions. Their self-aligning, lubricated for life bearings are designed to provide the quiet running required by many fan applications.
Shaded Pole Motors however, are not suitable for all types of duty. They are the simplest of the various single phase motor types, rugged and easy to manufacture.
However, the rotating magnetic field required to provide starting torque and fixed direction of rotation is produced not by a separate start winding, but by a single, permanently short circuited band of copper, the shading ring, fitted to the tip of each pole of the motor. Whilst this is simple, and conveniently, does not require either start switch or capacitors, it has two performance effects which limit the applications to which it is suited.
Firstly, the rotating field produced by the shading ring is relatively small, so a feature of all Shaded Pole motors is that start torque is quite low. This is ideal for fans and light mechanical duties, but insufficient for driving larger and heavier mechanisms with greater friction to overcome.
Secondly, the short circuited shading ring is in circuit whenever the motor is running and produces an appreciable power loss. This power loss is in the form of heat and cooling air is therefore required to dissipate the heat so generated. This is usually achieved by making the motor with ventilated construction, adding a small external cooling fan, or in the case of air moving motors, by situating the motor in the airstream of the fan. Motors are frequently referred to as being 'airstream' rated, and these should not be run without cooling air, otherwise they will quickly overheat.
Largely due to the losses caused by the shading ring, all shaded pole motors tend to have low efficiency, (25% is quite typical), and because the shading ring power loss is higher in larger output motors, the power output rating of this type of motor is generally limited to levels below 100 watts.
Fans applying less than 80 watts load to the motor, and particularly where some cooling air can pass over the motor body, are ideal applications for this simple and popular style of motor.
Ask our Technical Department if you are not sure whether a Shaded Pole motor is suitable for your application - they will be pleased to advise you.