Frigidaire Electri-Clean Ovens
FD introduced this first on a 30" free standing around two years after GE introduced this great feature about 1965. Self-Cleaning was about the best thing that ever happened to electric ovens, not only did this work saving feature really work, but the ovens baked much better [ much more even heat ] as a result of better insulation and used less power and kept the kitchen much cooler.
FD also used the Flair name on some 30" wide [ they also called these Twin 30s ] ranges with a top oven, the Flair versions had a top oven door that lifted up to open. The regular Flairs never got the SC oven feature, in fact this is a major reason that they faded from production, it was just not possible to insulate this type of oven well enough to make a SC oven out of it and people buying expensive ranges at this time usually wanted a SCO.
FDs first 30" and 40" SCOs and wall oven with EC were unbelievably complicated and as a result problem prone [ the same can be said about GE, WH and a few others first SCOs ]. Around 1969 FD and a few other companies like Thermador went to a new line voltage King-Seeley helium filled thromostat, that also used a hot-wire power relay. It was very interesting to note while every manufactures SCO worked the same way to burn food residue away by gradually heating the oven interior to around 800F they all did it with a different combination of the use of the bake and broil elements [ including some additional heating elements on some brands and designs ] they had to do this to get around patents that GE and others quickly placed on their designs.
The FD EC SCOs worked by applying 240 voltage to the broil element through a percentage switch that operated the broil element at about 80% power [ this allowed the oven to still clean well if it was connected to 208 power as the broil element would now run almost 100% of the time ]. The broil element had a catalytic converter above it near the oven vent to help burn away any smoke, meanwhile the bake element was connected to straight 120 volts which is constant on either 208 3 phase or 240 single phase power supply systems. This has the bake element putting out 1/4 the heat it would while baking [ about 650 watts ].
FDs clever trick in their SCO was a 1/4" thick plate of aluminum behind the inside of the oven door so the heat would evenly spread and assure complete cleaning of the entire heated area of the door. This was the reason that FD tried to get away from having a window in the door for so long [ and in my opinion almost no oven should have a window, they are usually just a dirty waste of power ]
I would say by a slight margin that FD SCOs did the best job of any SCO followed closely by GE-HP and Thermador, most other brands left more areas that were not completely cleaned.
John L.