Older coil elements

[fan-of-fans]

I remember seeing a few times older electric hotplates would have wire coils in a grooved porcelain ring, instead of the Calrod or Corox style elements. Never actually saw one turned on, but they always kind of scared me. Seems it would be easy to get a shock or possibly have the coil contact the pot or pan and short.

Were these kind of burners only used on hotplates or for other useage? Seem to recall reading that these were never allowed in some other countries and that's where the solid disc elements that were so popular in European countries and probably others came into being. While in the United States the rod style elements were introduced earlier on.

 

[combo52]

Open Coil Surface Elements

These were used on early 240 volt electric ranges, they worked well but had obvious problems with spill overs and cleaning, they were also not as safe or durable.

 

John

 

[norgeway]

Monarch

Used them much longer than anyone else, into the 50s on some ranges, like John said, touch one with a spoon or fork and it will light up your world, but people used to have enough common sense not to do things like that,,lol, they were used in deep well cookers on less expensive ranges into the 50s also,

 

[tomturbomatic]

It was the inherent dangers of these open wound coils in either firebrick or porcelain  holders that caused the European nations to mandate the cast iron elements with which research and progress stalled for decades. Of course, in this country, research continued and Hotpoint engineers developed the sealed rod element which enclosed the open wound coil in a stainless  steel tube. The open coil was insulated electrically with magnesium oxide and improvements were continuous. The magnesium oxide insulation is why there is the bright yellow light when a sealed rod element shorts internally. Hotpoint's discovery led to General Electric's purchasing the company to get the Calrod element which is why you see the note in Hotpoint ads of old that it was a subsidiary of the General Electric Co.

 

One nice thing about the old open coil elements sunk into channels in the firebrick or porcelain holders was that the intense heat of the element did not touch the pan so Pyrex and other brands of heatproof glass cooking vessels could be used without danger of thermal destruction on the elements. The sealed rod elements, unless used on slower speeds, had to have the wire used between them and the glass vessel to prevent breakage from thermal shock due to the fact that glass does not transmit heat very well from a place of high heat to a place of lower heat. Another nice thing about the open coil elements was that the firebrick absorbed a LOT of heat, which was not good for efficiency in the initial heating, but could be used to cook with the current off. When we were using a hotplate to cook in lodgings, I remember my mother using the percolator on it. She brought the water to perking on high then she shut if off and there was enough heat to perk the coffee for 8 minutes or so. Early marketing of electrical cooking used to emphasize the savings to be had of cooking while the current was off. The European cast iron elements held even more heat.

 

[northwesty]

I

have wondered if like deep fat frying over these, and then it spills over -- seems like a fire hazard if not a mess to clean up. Prefer the Calrod unit in the GEs

 

[tomturbomatic]

Well, with any electric surface unit, you are supposed to choose the size unit that is covered by the pan so that you do not have a hot ring exposed beyond the base of the pan, but a hot sealed rod element will set fat on fire if it boils over the top of the pan or is otherwise spilled on a hot surface unit. If the unit is not red hot, it usually just goes up in smoke.

 

With a gas burner, it is even more fun because oil at frying temperatures also vaporizes and the fumes can ignite if they come in contact with an open flame. Check for stories around Thanksgiving.