The Frigidair Flair Custom Imperial range was light years ahead of its time. In fact, so much so, its still quite futuristic even today, some 50 years after its introduction. One reason it was so advanced was its control system. Beyond the traditional duty cycle controllers common to contemporary ranges, the Flair also had a speed heat mode, and a heat minder mode. The focus of this entry is on the speed heat functionality.
Speed heat is pretty cool, in that it provides for much much faster initial heating than one would encounter with a standard burner. In a nutshell, speed heat flash powers a 120V burner at 240V during initial heatup. In effect, the 1250Watt burner becomes a 5000Watt burner… which makes it get hot super fast. Granted, such is a very time limited operation, or the burners lifespan would be incredibly short as its effective watt density is 4x greater than the normal design criteria.
The time of 230V operational status is a function of the initial setting of the burner control knob after coming from an off position such as shown in the following table.
230V Flash time
- High 31 Sec
- M. High 31 Sec
- M. Low 22 Sec
- Low 17 Sec
- Simmer 15 Sec
In addition, it should be noted that interrupting the flash time, or trying to repeat the flash interval without an extended period of time with the knob at the off position will have only a minimal effect.
While I am not privey to the internal details of the speed heat burner, my guess is it was subject to a higher degree of quality control/inspection than regular 1250Watt 120V burners. The reason being, with 4X greater watt density, the presence of a void and or differences in magnesium oxide insulator density would likely seriously reduce the MTBF (mean time before failure) of the burner, where as such would have minimal affect on a regular burder.
In todays design world, such would be impossible. Marketing guys and bean counters primarily focus on cost, not on quality nor on 20 year + MTBF as of eras long past. Even quality methodologies focus on consistency and inspection / sorting processes are severely looked down upon. My guess is inspection / sorting was likely a key aspect of the speed heat burner assembly process 50 years ago.