Refrigerating and Air Conditioning Pressure and Temperature Controls – Commercial
Automatic, hydraulic bellows actuated, dual function, high pressure and low-side temperature control with extended capillary tube, for commercial and industrial refrigeration equipment applications, equipped with fully adjustable, user friendly range and differential settings, and tilting mercury bulb switching, in attractive, streamlined heavy, plated steel enclosure, now telling the many stories of natural use on a farm milk cooler in York Region, Minneapolis-Honeywell, Circa 1945.
Features:
Attractive, simple elegant styling with plated steel, bright enclosure, long radius streamlined corners and decorated nameplate cover in green.
A mercury bulb controller, with precision mechanism, it includes calibrated scales for cut-out and differential field adjustment and out-board replaceable and interchangeable bellows.
With miniature, built-in pendulum to help ensure plumb mounting needed for the precise operation of the mercury bulb at designated control point.
Once beautifully engineered, it is enclosed in stream lined, formed steel, bright plated enclosure with, full front, access cover: but now stained and spotted with white paint telling the stories of many years of use on Ontario farm near Aurora, on a typical, early, mechanically refrigerated, water bath milk cooler
Technical Significance:
Representative of leading practice in the engineering of sophisticated state of the art, dual function, automated refrigerant high pressure cut-out and low-side temperature controllers of the mid 20th century.
Built on a platform that was readily adaptable to a wide range of functions and applications it represented a significant advance in the field, enabling an ever widening range of functionality, and equipment manufacture’s needs. [See also ID # 163, 7.02-8]
New also for the period was the attention given by leading control manufacturers to product support. The L series, in its many variations, is well documented in company catalogues and in field instruction sheets, variously dated through the latter 1940’s and 50’s.
The control was made in a number of versions for industrial, as well as commercial refrigeration applications, including farm milk coolers, refrigerated display cases, walk-in coolers and freezer cabinets.
Industrial Significance:
The Minneapolis-Honeywell L control series represented well the mid-century control technology of the times, enabling the development of a vast range of new refrigeration applications by the Canadian refrigeration industry.
