Can a Microwave run continously?

[Chetlaham]

Can a countertop microwave oven run for half an hour+ without overheating, tripping a thermal switch or burning out the magnetron?

https://www.amazon.com/gp/product/B00345V43K/ref=ox_sc_act_title_1?smid=A1YJ4VH1RTKH0Y&psc=1

I've always assumed microwave ovens were intermittent duty devices <6 minutes run time. I have various frozen family size dinners that call for 20-45 minutes for heating time.

 

[combo52]

Yes

Nearly all major appliances and smaller appliances can run continuously, without any harm or overheating.

What appliance cannot run continuously this is a quiz, see who gets the answer first.

John

 

[Chetlaham]

Thank you. I love your experienced replies on appliance matters!

Its good to know I can use my countertop to cook full family size meals. My current Sharp R21LCFS doesn't have a power level function but I know that might not even be a setback. It is good to know I can set the knob to a full 6 minutes 3 or 4 times in a row without significantly shortening the life of the oven.

I'm actually debating on purchasing a second microwave oven but one with a keypad so that I can cook for longer than 6 minutes while having the option of multi stage cooking. I can cook lasagna, casseroles, pies, ect in the touch pad in an hour while heating rolls, gravy, sacuses, ect in the knob version side by side.

 

[petek]

Well back in the day, 70s & early 80s , microwave cookbooks touted cooking whole meals and roasts in them which could run around 45 minutes.

One small appliance you can't run for long though are KA and Kenwood planetary mixers. They're good for about 10 minutes maybe even less with a heavy load before requiring a cool down period.

 

[Chetlaham]

Good to know that its also applicable for countertop micros. They did a Whole chicken here in an over the range unit, turned out really good:

https://www.google.com/url?sa=t&rct...usg=AOvVaw3ch-ABBaTuKDP1ewR4Djdb&opi=89978449

I'm so blown away at the even thorough cooking of my Sharp R21LCFS that it has opened avenues into considering microwaving meals more often.

 

[Chetlaham]

GE Thermo Probe Models

Before I forger, I remember in the 90s GE offered over the range models with a temp probe that plugged into the side of the cavity. The idea behind it was I'm guessing like that in the video. You cook the chicken until it hits temp in the thickest part then you let the cooking process finish. Rather ingenious now that I think about it- but I admit that I've never seen or heard of anyone taking advantage of the temp probe feature or if it is even offered new.

 

[petek]

When we moved to Calgary in 86 I bought the full size GE (Baycrest rebadge) which had auto everything including the probe. It was by far the best mw I've ever had. It had no turntable yet cooked everything evenly. It was always the top scorer in CR's ratings as well. It had a metal shelf, auto roast with the probe, auto defrost, auto cook. You just put your food in covered, hit the appropriate auto button and that was it, no need to add the weight or amount. I'm a bit forgetful but I'm sure we had it when we moved here in 2006 but it eventually died. Could be wrong about that. After which I used my old Amana Radarange for a while till it had some issues and went down into the basement where it sits today.

 

[mrboilwash]

Actually I`ve got countless of appliances that are not supposed to run continuously from vintage to brand new.

Picture #1
my 50`s kitchen motor has "KB 10 min" on the rating plate which means "Kurz Betrieb 10 min" or "Short term operation" in English.

#2 is a cheap modern file shredder wich calls for a 30 min cooldown after a 1 min use.

#3 is my new Oster blender that should not run for longer than 2 minutes.

Could go on and on with this quiz but I think I made my point already.

As for microwaves I think to recall the older ones with mechanical timers went up to 45 minutes maybe even longer, so I`d assume that continuous operation should not be a problem.
Except for maybe the food catching fire after a while.

 

[gizmo]

Reply to John's quiz

Lots of small kitchen appliances aren't rated for continuous operation.

I have seen mainly food processors, stick mixers and blenders with short on cycles - the worst I've seen was a cheap stick mixer with 30 seconds on / 5 minutes off cycle. (Max usage time 30 seconds, then must rest for 5 minutes before being used another 30 seconds max!)

 

Slightly off topic... It's not exactly a duty cycle, but just last week I got rid of a good quality Panasonic bread maker (gave it to an opp shop) because after baking a loaf, you can't do ANYTHING until it has cooled to below 40 degrees C. If you try, it flashes a "hot" message till it has cooled. Not even a bake only function - which means if your bread comes out a bit undercooked, you can't just put the loaf back for another 15 minutes baking. I bake gluten free bread which often needs a bit longer than the standard cycle. I have replaced it with a Breville which has a better shaped loaf pan and does allow an extra bake-only cycle immediately after a loaf has completed a cycle, so I can give it an extra 15 min or so if needed.

(Though I am finding gluten free bread is much better baked in a proper bread pan in an oven, than in a bread machine. Even special GF cycles don't rise long enough or bake long enough.)

 

[henene4]

The "hot" message is probably to prevent the yeast from dieing if you try to cook 2 loafs after each other.

That feature being active on the just bake setting seems like a programming oversight.

On the topic of microwaves duty cycle: If I can set my microwave to 90min, I don't see why the duty cycle would be less.

I know that for example the EU BSH Oven/Microwave combos step the power down from "Max" which is either 800 or 900 watts to 600W of the course of 90s.
But it can sustain that continuously.
With any bake mode selected that is limited to 360W, but also continuously.

Most of these duty cycle things are for small appliances where additional cooling would mean weight or size increase (or sometimes even cost).

Since you wouldn't use many of these things long anyway, it usually isn't an issue.
But some manufacturers take it a bit to far - can't purée a soup in 30sec, can you...

 

[Chetlaham]

@mrboilwash: Lucky. My current microwave only goes up to 6 minutes which got me double questioning if the oven has the ability to withstand 45 minutes of cooking. 2-3 minutes is typically enough for reheating, but cooking meals is asking for way longer times. I'm itching to try a plate of raw drum sticks or a whole chicken.

That 10 minute protector in pic # is really neat. Does it switch both the live and neutral since Schuko plugs are not polarized?

 

[mrboilwash]

Chetlaham
It`s not a protector switch, it`s just a rating plate which indicates voltage, watts and continuous run time. The hole in the center just seems to hold a rubber part in place to lower vibration or noise from the motor.

 

[Chetlaham]

Oh, my mistake. I thought the rubber part popped out like a circuit breaker to protect the motor if it ran beyond 10 minutes, but that was me making a bunch of assumptions.

 

[DADoES]

 
Chet, your MW is aimed at commercial use.  The limited timer range surely is related to that ... self-serve at a convenience store or hospitality station or staff heating prepared portions at a fast food venue or restaurant.

 

[DADoES]

Paper Shredders

 
All of the several office paper shredders I've used have a stated limited-time duty cycle, with an auto-reset thermostat that kills the power in instances of overheating.

 

[Chetlaham]

That makes sense. I guess its to deter someone from accidentally setting a burrito to 30 minutes?

Given that this unit could see microwaving may times in a row and being a commercial model construction wise I'm guessing this can handle 45 minutes of cooking better than a conventional domestic microwave.

It has been 20 years since I've entertained the idea of advanced cooking in a microwave, but after experiencing the performance of this one I am seriously getting a lot of ideas LOL.

 

[114jwh]

What appliance cannot run continuously this is a quiz...

Fun idea, here's my stab at it:

Although this isn't probably the answer, I believe most modern ovens have some sort of safety feature built in that will shut off the oven by default after a predetermined period of time, such as 12 hours. As I understand, there is usually a function to override this safety feature by putting the oven in Sabbath mode when necessary.

I don't think a refrigerator or freezer compressor can run continuously either (by design). It would make it way too cold. However, not sure if this counts as the fridge itself is technically still "on" even when the thermostat is cut out. On second thought I suppose the same would hold true for an oven from a technical sense so I'm stumped [this post was last edited: 1/21/2024-14:26]

 

[circlew]

If someone is planning on using an appliance such as a mixer, blender, or toaster for hours on end, it would probably be wise to buy a commercial model.

 

[parunner58]

In my kitchen in Pennsylvania we had a GE Profile Convection Microwave. The longest I ever ran it was 90 minutes straight, BUT. I used the Combination setting to cook the best meat loaves ever. It had three different setting. I used setting 3 which was the heating temp was 350 degrees and the microwave was set for 75% power. But i don't think you could count this as continuous as the heating element is cycling off/on as in a regular oven and the same for the magnetron since it was using 75% power, but the convection fan was on constantly. Am I correct in my thinking?

 

[Chetlaham]

Cycling Magnetron

I'll let John answer however IMO a power level less than 100% does not count as continuous operation. Same for alternating between microwaves and convection. The fan still runs but the tube and transformer are not generating heat during the off cycle.

My Sharp R21LCFS does not have power level however so it would be a straight run.

 

[combo52]

What major appliances can’t run continuously

When I made my quiz question, I should’ve said what major Appliance, I’m sure there are lots of small, portable electrical things that are not supposed to run continuously, although surprisingly not that many.

But I was thinking of major appliances, and things sold by a major appliance manufacturers, a refrigerator or freezer certainly could run continuously and often do with no harm to the compressor, fan motors, etc. yes it would get too cold and they normally don’t run continuously but there are thousands of refrigerators out there right now running continuously because of bad temperature controls, etc.

But there is a major Appliance in the majority of American kitchens that cannot run continuously no one’s mentioned it yet.

John

 

[gizmo]

In the majority of American kitchens...?

Garbage disposal?

(they are almost unheard of here, in fact I believe no longer sold new, but common in USA?)

 

[DADoES]

 
Cannot run continously, as that isn't possible by design of onboard safety components?

Or shouldn't run continuously, as the user is strongly advised not to do so for reason of avoiding damage?

 

[combo52]

Cannot run continously, but will not be damaged by trying.

John

 

[estesguy]

Electric oven

The heating element in the oven will not stay on continuously even though the oven is on is my only guess

 

[Chetlaham]

Trash compactor?

IF not that I'm also putting in my vote for Garbage disposal. I'm guessing (assuming) that it will run until the red button on the bottom pops out from the motor getting too hot.

 

[petek]

I would say a kitchen hood/exhaust fan could run continuously. Do I win the luggage?

 

[circlew]

Well, I don't think it's a trash compactor, as he said "in the majority of American kitchens", and that appliance doesn't fall into that category. I'm thinking a dishwasher.

 

[combo52]

I was thinking of a garbage disposal

There’s no cooling system in a residential garbage disposal and they’ll only run for 1520 minutes at best before the thermal overload just cuts the thing off and it Has to cool for quite a while.

A trash compactor actually can run continuously I’ve seen it happen when the start switch sticks customers have come home and the thing is compacting over and over again possibly for hours on end doesn’t seem to hurt them.

An electric oven bake element can run continuously again I’ve seen it done many times Used to have a friend that was always running out of heating oil and they would open the door on their Roper, built Kenmore electric oven and turn it on and let it run all night to try to keep the house warm. Yes, modern ovens with electronic controls. Generally only run 12 hours, but you can override it by using the sabbath mode..

The pump motors in modern dishwashers are not continuous duty but as they designed into the cycle, you can run cycle after cycle with your dishwasher Because there’s enough periods of soaking, etc. built into the cycle that it won’t damage the motors.

This is the wonderful thing about modern electrical machines. They never need a rest basically.

John

 

[paulg]

Electric can opener

I believe that an electric can opener is one appliance that cannot run continuously.