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Modern kitchen electric range

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jonnieA

Electrical
Mar 8, 2021
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In a modern range, are all of the onboard electronics such as the clock and timers 240 volts? I'm guessing they are such that they don't create a current in the neutral due to the unbalanced load they would create. I ask this question with regard to the chassis shock hazard when connected with a 3 wire plug instead of a 4 wire plug.
 
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Historically, before electronic modulation circuits became common, lower heat settings were achieved by connecting a 240 Volt element across 120 Volts for reduced output.
The current drawn by the clock pales in comparison.

A typical transposition sequence.
Highest setting, = #1.
#1. Two 240 Volt elements fed 240 Volts
#2. The larger 240 Volt element fed 240 Volts.
#3. The smaller 240 Volt element fed 240 Volts.
#4. Two 240 Volts elements fed 120 Volts.
#5. The larger 240 Volt element fed 120 Volts.
#6. The smaller 240 Volt element fed 120 Volts.
#7. two 240 Volt elements in series on 120 Volts.
The more mature fellows will remember the once common 8 position switch controlling electric range elements.
That was 7 heats and off.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
A modern kitchen range uses electricity for the igniters and the clock.

I’ll see your silver lining and raise you two black clouds. - Protection Operations
 
NEC requires four prong receptacles for new construction, but I believe the three pronged ones are grandfathered. When you buy/install a new electric range or dryer, you'll be asked what sort of receptacle you have so the correct cord is provided.
 
It'd be a manufacturers choice and different ones could do it differently. To me, a power supply running off 120V would be "safer" than running it off 240V.
 
Given that there may be several hundreds of Watts being supplied at 120 Volts via the neutral, any unbalance on the neutral caused by a clock may be immaterial.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Ours had a low voltage system internally, but I never checked if it was 12V or 24V.
Now I use gas ....

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
 
A bit off topic but I had a co-worker that, in his house, could only watch TV with the electric range turned on. I believe he ended up having an open neutral in the distribution wiring.
 
That was common decades ago when residential mains were fuse protected rather than breaker protected.
This will be a 120/240 Volt circuit.
He has a blown main fuse or an open hot line.
One half of the house circuits work fine on 120 Volts.
The other half of the circuits are dead until the stove is turned on, then light loads will be in series with the stove element and will work.
Many of the heat settings on the stove may not work.
The young and inexperienced want to think an "open neutral".
They are wrong.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Now THAT is interesting . . . and apropos, as our 1970's vintage 200A residential service is protected by fuses.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
 
I was trying to visualize the power flow. I had explained it to him years ago. He did look and found a wire bad been chewed through by a squirrel.
 
An older gentleman that I worked for many years ago told me that in the 40s it was a common issue around X-Mass time.
With all the lights on in a house and the oven and lots of elements going cooking X-Mass dinner, a main fuse would blow.
Many mains were only 60 Amps in the 40s.
In the 50s 70 Amp breaker panels were common for a few years.
By the late 50s 100 Amp breaker panels were common.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
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