Meltdown!

[RJSakowski]

Well not quite but it could have been. Our Frigidaire Gallery range by Electrolux modulates the burner by switching a relay on and off. The cycle is about 15 seconds with the ratio of on time to off time determining the burner temperature. Last Saturday, the large outer element didn't switch off. Fortunately, we noticed it soon enough so the only casualty was a slightly burned dinner.

This had happened once before and I ordered several spare relays and I happened to have a spare control circuit board as well so it was a fairly straightforward repair. The concern though, is if this had happened while we weren't in the immediate vicinity, the consequences could have been serious or even fatal. Checking on line, this is not an unusual occurrence.

The relay that failed on this occasion was a Potter & Brumfield T7CV5D-12 rated for 240 v.ac @ 10 amps. It has a average service life of 100K ops @ 600 ops/hr.. At 4 cycles/minute, this is 240 ops/hr which would imply 417 hrs of service. At 10 min/day of average use time, that equates to 6.85 years. I have no idea what the actual current draw is for each element but conceivably all four top elements plus the oven could be drawing simultaneously, along with the oven so I'm guessing something like 5 - 6 amps.

The use of a relay to switch a significant load multiple times a minute seems like poor design to me. The additional possibility of of fire in the event of failure during unmonitored usemakes this even more serious. Certainly, more reliable means of power switching is available. Triacs have been around for decades and are a proven reliable means of switching. Additionally. it wouldn't be that difficult to add reliable over temperature cutouts.

 

[matthewsx]

Frigidaire and Kenmore Smoothtop Electric Ranges Recalled Due to Fire Hazard

Contact Electrolux or register online to participate in the recall. Based on the serial number, it will be determined if consumers have a range that can be repaired or not. Consumers with impacted ranges should contact Electrolux for steps to avoid a burn injury, including not leaving...

www.cpsc.gov

get rid of it, not worth your life….

 

[Deleted member 69715]

Maybe contact the manufacturer to see if there's a "fix" or some sort of peace offering towards a new stove/range. And Matthwsx is right. Replace it before it becomes a really serious problem.

 

[C-Bag]

What were they smoking when they came up with that POS! It would drive me crazy knowing this time bomb was lurking in my stove. The least they could have done is installed a Hobbs meter, but that would be admitting their deadly design. I would have thought it would fail safe, not burn your house down. Glad I have our 75yrld gas stove.

 

[twraska]

Our 2017 Whirlpool stove top was recalled for automatically turning itself on.

 

[MrWhoopee]

Yet another example of "improving" a tried-and-true bullet-proof design. Remember when major appliances outlasted their owners? We got a "new" stove a few years ago. I insisted on the old-school coiled burners and mechanical switches.

 

[RJSakowski]

Frigidaire and Kenmore Smoothtop Electric Ranges Recalled Due to Fire Hazard

Contact Electrolux or register online to participate in the recall. Based on the serial number, it will be determined if consumers have a range that can be repaired or not. Consumers with impacted ranges should contact Electrolux for steps to avoid a burn injury, including not leaving...

www.cpsc.gov

get rid of it, not worth your life….

Thanks for that info! Funny that Frigidaire/Electrolux didn't send out a recall notice. We are registered owners and had a recall notice about a different matter pertaining to the same range.

Changing ranges isn't a simple matter since we bought the whole kitchen suite consisting of the range, the dishwasher, the refrigerator, and the microwave. Changing the range would mean that that appliance no longer matches the rest of the suite and I expect that my wife would want all new appliances. Since they are all built-in, it means a possible retrofit to a $70K kitchen.

There would be a solution to this issue. A missing pulse detector could be used to monitor the heating elements. Since they cycle every fifteen seconds, if the current didn't shut off within a period of 20 seconds or so, it would release a latching contactor which would kill power to the entire range. The high heat position on the burners is the only position that doesn't cycle and it is seldom used and never unattended. There are six elements that would need to be monitored but the front end would be logic circuitry so low cost. The contactor could be any of those commonly used for E-stop on heavy machinery.

 

[markba633csi]

I would have thrown a triac in there
We had an old Electrolux vacuum that was terrific
Wish I still had it

 

[FOMOGO]

This is just one reason I love my gas range. It's going on 30yrs, and all I've ever had to do is tighten the oven door handle. Mike

 

[matthewsx]

Thanks for that info! Funny that Frigidaire/Electrolux didn't send out a recall notice. We are registered owners and had a recall notice about a different matter pertaining to the same range.

Changing ranges isn't a simple matter since we bought the whole kitchen suite consisting of the range, the dishwasher, the refrigerator, and the microwave. Changing the range would mean that that appliance no longer matches the rest of the suite and I expect that my wife would want all new appliances. Since they are all built-in, it means a possible retrofit to a $70K kitchen.

There would be a solution to this issue. A missing pulse detector could be used to monitor the heating elements. Since they cycle every fifteen seconds, if the current didn't shut off within a period of 20 seconds or so, it would release a latching contactor which would kill power to the entire range. The high heat position on the burners is the only position that doesn't cycle and it is seldom used and never unattended. There are six elements that would need to be monitored but the front end would be logic circuitry so low cost. The contactor could be any of those commonly used for E-stop on heavy machinery.

It’s your home, and you have better than average technical ability so whatever solution is right for you is best.

For me, I’d rather have non-matching appliances or spend $70k than risk having a fire.

Stay safe my friend.

John