How many appliances should be on one breaker?

Then you open the door and a couple of 60w lights come on. ;-)

Why on earth would a breaker trip at 80%? Breakers (and fuses) trip at 100% or greater load, depending on the length of the overload. You can always run for 100% forever.

In the UK, most houses have every single outlet in the house on one breaker. Another breaker does lights, another does the water heater, another does the shower, another does the cooker. But all appliances smaller than that, that you can move around, are on the same one. It's 30 amps at 240 volts.

Not so much now. Many have gone to LED. Nice bright lighting with very little energy.

Every outlet on one breaker? Either you all live in small shacks, or once again, you're full of s*it. I have odds on the latter.

The code is silent on what you plug into the laundry circuit, only that it only serve the laundry area. It can be your washer, gas dryer, steam iron or a counter top microwave if that is where you put it. Lots of things are recommended but we really only enforce what is required. Article 90.1(C) Intention. This Code is not intended as a design specification or an instruction manual for untrained persons.

Unfortunately there are plenty of people who will say NFPA has been getting into the area of design.

Besides the problem that they specify different circuit voltages and amp ratings, you also have the limitation of 50% on fixed in place equipment. It is not unusual too see a wall oven and a cook top on the same circuit tho. It would depend on the installation instructions and might require supplemental over current protection in the separate disconnects. An example would be a 50a circuit that was feeding a range, then in a remodel you put in a wall oven and cook top. You could split that 50 into 2 20s or a 20 and a 30 with the appropriate fused disconnects at each one. (assuming the appliances do not say they are OK on a 50).

Perhaps your British breakers do, not over here. It's a safety feature.

I love it that I don't have to worry about my wife using the microwave while I make coffee and toast. Since I had enough spare circuits...why the heck not use them?

Any cooktop or wall oven I've ever seen has had it's own fuses, so no problem putting them on a 50 amp breaker.

You use a ring circuit, totally different breed of cat. Aren't the outlets also protected at 10a?

Kind of true, but it's very common to have high wattage electric water heaters. So while the total monthly usage may be low, the peak numbers can be pretty high

Simply not true. If you look at the trip curve the trip is typically at 1.10% +/- 1.5%

You can have as many small appliance circuits as you want in the kitchen. (minimum 2)

That must be a Canadian thing. I have not seen that here and I just bought a new GE oven. My cooktop is 14-15 years old tho. Neither have fuses, nor did the appliances they replaced.

"As you add up the electrical loads, keep in mind that a wire rated at

If you would take the time to look at a chart of how breakers change with the temperature you would know something about them.

One major company specifies theirs are rated at 104 deg F. They will trip at the rated current at that temperature after long time period. If around zero or 140 deg F then they will trip about 20 % higher or lower.

If the current is slightly over the rating they will take a long time to trip (maybe all day) and with about 1.5 times they can take up to around

Fuses act in a similar way.

Same here, I've never seen a fuse in an oven, stove or cooktop either. Not saying it can't exist, but if it does, it's not common.