|HHCC Accession No. 2006.192||HHCC Classification Code: 16.04-5B|
A mid 20th century, 60 cycle, Canadian made, shaded pole, induction motor, with custom three point, vibration isolating, vertical mount, engineered for fan coil applications on refrigerated self-service display cases, used throughout the 1960’s and beyond, helping to change the face of Canadian food merchandising in Canada, with greater range of fresh vegetables and meat products as well as frozen foods, all now available self-service, Electrohome, Circa 1963. [two of a matched set of 3, all new and unused, see also ID#315 and 317]
Image Gallery (2 Images)
16.04 Electric Motors - Single Phase, Shaded Pole and Universal
Electrohome, Kitchener, Ont
5 x 3 ‘ round
Exhibit, education, and research quality, illustrating the engineering and construction of a mid 20th century, highly customized, shaded pole, 60 cycle induction motor, designed by a uniquely Canadian electrical manufacturer, specifically for fan-coil cooling unit applications on self service refrigerated display cases,
From York County (York Region) Ontario, once a rich agricultural hinterlands, attracting early settlement in the last years of the 18th century. Located on the north slopes of the Oak Ridges Moraine, within 20 miles of Toronto, the County would also attract early ex-urban development, to be come a wealthy market place for the emerging household and consumer technologies of the early and mid 20th century.
This artifact was discovered in the 1950’s in the used stock of T. H. Oliver, Refrigeration and Electric Sales and Service, Aurora, Ontario, an early worker in the field of agricultural, industrial and consumer technology.
Type and Design:
Mid 20th century, classic, shaded pole induction motor, engineered for fan duty on an early generation of self service refrigerated display cases. 0.2 amps. 220 volts, 60 cycle Sleeve bearings, oilers
Ferro-magnetic two piece body No base plate, designed for body strap mounting Three point, vibration isolating, vertical mount,
Control and Regulation:
Targeted Market Segment:
Representative of a new generation of sleek, compact, more electrically efficient and customized shaded pole motor technology for the 1960’s Designed for vertical mounting these motors, would typically be found in multiples of two, three, four or more arranged along the length of the refrigerated display case. New for the times, as a protection against personal and property damage due to over heating, these motors are equipped with ‘lock rotor protection’, ensuring that motor exciting current would not exceed safe levels even if the motor stalled.
By the 1960’s the success of shaded pole motor technology would help move the Canadian commercial refrigeration industry solidly into a new generation of more compact and efficient forced air cooling units, making possible a wide range of new refrigeration appliances and fresh and frozen food merchandizers. The single phase alternating current induction motor has a public face of great simplicity - no commutator, brushes, governor nor switching mechanism to get it started, simply a field winding and solid state [squirrel cage] rotor mounted between two bearings. Its ‘shading pole(s)’ consisting of single turn of wire strategically placed around its pole face(s), is all that is required to start rotation. Yet the shaded pole induction motor is a marvel of early 20th century electrical design engineering. [See Reference No. Chapter XIII, P. 297]
One of a matched set of three motors, all of the same serial number, suggests that they came from the same production run in Electrohome’s Kitchener Ontario plant in 1963. The set of three identical motors represents the mode of application in which multiple motors where used together in a single refrigerated self service case All new, unused and pristine the set provides an authentic reflection of the engineering, production, materials and manufacturing processes of the period
A marker of the ‘golden’, post W.W.II years of refrigeration manufacturing in Canada, which among other things would encourage electric appliance and equipment manufacturers, like Electrohome, to enter the small motor’s [see also ID#312]. Its low cost and unique speed-torque characteristics made the shaded pole induction motor ideal for small fan applications of 1/20th HP or less. A ‘one-of-a-kind’, ‘just-in-time’ technology, it quickly found a special place in 20th century appliances and electrical equipment, where air circulation and ventilation where imperatives.
The shaded pole induction motor quickly became an integral, often unobtrusive, component part of the appliances and equipment that increasingly invaded the Canadian home and place of business starting in the early 20th century. Typically custom engineered as component part of a larger piece equipment to ensure air circulation and ventilation, the shaded pole induction motor has enabled much and in so doing has change much of life for Canadians, as an essential part of our 20th and 21st century technological experience. Of equal significance is the ‘shaded pole synchronous motor’, which made possible the electric clock and a multitude of automatic time controlled devices throughout the 20th century [see for example Group 12.08 and 12.10 control devices]
G. Leslie Oliver, The T. H. Oliver HVACR Collection
HHCC Storage Location:
‘Fractional Horsepower Electric Motors’, Cyril Veinott, McGraw Hill New York, 1948, Chapter XIII, P.297 ‘Rewinding Small Motors’, Daniel Braymer and C.C. Roe, McGraw Hill, 1932 ‘A course in Electrical Engineering, Volume II, Alternating Current’, Chester Dawes, McGraw Hill, 1934, Starting single Phase Induction Motors, P. 362. ‘The Fractional Horsepower Motor and its Impact on Canadian Society and Culture’, G. Leslie Oliver, Material History Review, Vol. 43, Journal National Museum of Science and Technology, 1996.