An example of innovative, mid 20th century combustion safety control technology that would dominate the field of household automatic oil heating through much of the balance of the century; stack mounted, bimetal heat actuated safety switching, electro-magnetic relay controlled; equipped for intermittent ignition, heat anticipation, 3 wire room thermostat, Type RA117, 60 cycle, Minneapolis Honeywell, Toronto Circa 1948. [See also ID#234]<\/p>\n\n\n\n
Features:<\/strong> Technical Significance:<\/strong> Industrial Significance:<\/strong> An example of innovative, mid 20th century combustion safety control technology that would dominate the field of household automatic oil heating through much of the balance of the century; stack mounted, bimetal heat actuated safety switching, electro-magnetic relay controlled; equipped for intermittent ignition, heat anticipation, 3 wire room thermostat, Type RA117, 60 cycle, Minneapolis Honeywell, Toronto Circa 1948. [See also ID#234]<\/p>","protected":false},"author":1,"featured_media":20886,"comment_status":"closed","ping_status":"closed","template":"","cpt_portfolio_group":[209,206],"class_list":["post-20885","cpt_portfolio","type-cpt_portfolio","status-publish","has-post-thumbnail","hentry","cpt_portfolio_group-heating","cpt_portfolio_group-residential"],"yoast_head":"\n
\u2013 Cabinet in black \u201cripple\u201d finish part of the look of the day, based on the metalic coatings technology of the day
\u2013 Handsome corporate monograph in distinctive Minneapolis Honeywell Red
\u2013 Original instruction sheet
\u2013 Original field installed wiring ends
\u2013 Original porcelain cable box connector
\u2013 Original wiring diagram on inside of cover<\/p>\n\n\n\n
\u2013 Of special significance is the 60 cycle engineering of this controller, built for the Ontario market following frequency standardization, which took place in the closing years of the 1940\u2019s in much of the province. These devices, being electro-magnetic, were frequency sensitive. The much smaller rear mounted transformer used to provide control circuit power tells the story. The 25 cycle equivalent is shown on item ID#234.
\u2013 With the introduction of new generation of integrated, relatively reliable control systems for household heating in the early 1940\u2019s a new era of mass produced technology had arrived, setting the stage for a new, Canadian mass market.
\u2013 It combined up-dated, bimetal combustion control technology with the three wire, heat anticipating thermostat, \u2013 providing comfort, safety and reliability levels unheard of a decade earlier.
\u2013 By the early 1940\u2019s Minneapolis Honeywell\u2019s unitary designed, combustion controller, the RA117A Protectorelay, had arguably become a kind of standard of achievement for the home, automatic, oil heating industry in much of Canada.
\u2013 The fragile and potentially poisonous mercury bulb switching of earlier combustion controls was replaced here with quiet, reliable, electro-magnetic and bimetal driven snap action contacts,
\u2013 A significant design consideration in the development of unitary, stack-mounted controls was the high ambient temperatures to which they were subjected. High temperature wiring and heat shielding were new design requirements to be dealt with.
\u2013 These embryonic, electric automated systems were representative of the earliest introduction of complex systems into the Canadian home. See Note #2<\/p>\n\n\n\n
\u2013 The control cabinet cover in black \u201cripple\u201d finish is representative of the trendy look of the day, based on the new, metallic coatings technology of the period
\u2013 By the mid 1940\u2019s the HVACR industry recognized that a new era in the popularization of automatic home heating equipment was under way. Unitary designed, oil home heating equipment had evolved into a \u201chome appliance\u201d, on which many householders would now become heavily dependent.
\u2013 This new, widespread dependency on automatic heating, throughout Canada\u2019s long cold winters, would require the industry to strive for enhanced performance in matters of reliable, maintainable and readily serviceable equipment, with readily obtainable replacement parts.
\u2013 Public expectations for 24 hour emergency service was part of the new world of popular technology that had been created. Honeywell and other manufacturers would respond by providing a line of rebuilt controls for field service people to stock for emergency purposes.<\/p>","protected":false},"excerpt":{"rendered":"