Circuit Breaker 22AIC

The have two version of 20A breaker, 10AIC and 22AIC. I guess I don't really know what they mean. It's plug-in microwave and fridge on the same circuit.

AIC is Ampere Interrupting Capacity, so it is probably 10kAIC and 22kAIC.

There are 4 breakers and 3 empty slots in the panel. I guess they really cut corners in this apartment. I might add some more breakers, but making holes for wires is the problem.

I'll try not to use the electric stove and microwave at the same time, although they are on separate breakers. I'd have to unplug the fridge to use the microwave.

It's 22KAIC, but they usually omit the K

Nothing on the circuit that add up to 20A.

How long is a piece of string?

It goes without saying, because no one says it. A fridge is about 300W or around 3A when running. That's about the same as maybe 5 laptops depending on the laptop and what they are running at the time.

The only individual heavy load is the microwave which ranges from 600W to 1,400W, depending on size.

But we simply don't know enough. 10 laptops can use over 1,000W alone, if they are high end, running heavy programs. So, they should be ok with the fridge, but the microwave has to go on a separate circuit, or the fridge has to be turned off while the microwave is running.

What's the current draw of the fridge while running? While defrosting? They might be compatible on a 20A circuit.

If I unplug the fridge, or when it's silence, microwave is fine. Sound like I need a relay circuit to disable the fridge from the microwave. Namely, a fridge outlet on the microwave.

What is your 'near'?

Fridge: 310KWhr/year = 35W average (no info on motor) Microwave: 1500W Laptops: 60W to 90W.

No dishwasher or coffee pot.

I like that you provided the "average" power draw of the fridge. How do you expect to use that in solving your problem?

It just occurred to me. You have the fridge to chill all the laptops so you can overclock them!!!

Here's the most direct route to solving your problem. Get a microwave that is 600 watts, rather than the behemoth 1500 watt monster. Do you actual defrost turkeys in it?

When my son was in a dorm room he could rent what they called a 'microfrige'. It was a microwave on top of a small refrigerator. I would assume it was set up so both of them were not drawing power at the same time. Due to the cost of the rent we decided just to buy a microwave an small refrigerator.

I think that's an overly large assumption. That tiny refrigerator probably draws 100W when running. It has no defrost. The microwave is likely 600W and just barely makes popcorn. No need at all to worry with the two running at the same time.

probably more that 20x that when running (google says US average fridge is 725W), and the start up current can be 3x that

the start up current can be 3x that for a few cycles

(725+1500+60*10)/120V = 23.5A that's more than 20A .....

the AIC rating really only matters in a dead short

and while you are busy optimising the irrigation system the plans dry out and die

there's; too late, too expensive and good enough

You answered your question in another post:

"Typically a refrigerator runs on 35% duty cycle, (65% for a freezer). This means that if you take the running watts and multiply it by 35%, you can get an idea as to how much power the average running amps will be."

Not really. They are air-cooled.

It's fairly standard sized microwave.

I still don't understand Fred's concern about relay switching the fridge. I got some 30A relay contacts that should be enough. Half of the laptops have batteries, which I can also relay switch off while using the microwave.

I'm pretty sure I didn't post that. Regardless, that would be a combination of an average with a rule of thumb, so not of much value. The point is, your appliance has a plate with the actual power rating while running. Why don't you look at that? Not the motor, the appliance. You've also said nothing about the size of this appliance. Is it a dorm room size fridge? A massive double door kitchen behemoth? Something in between? As is usual with you, only the barest minimum of information is provided and then the guessing begins.

LOL!

1500W is not a standard size microwave. That's as large as they get for home use. 600W to 1000W is much more typical. Should I assume you actually read the rating plate to get the 1500W number? Or is this another "average" you pulled off a web page, somewhere?

You will wear out the relays in relatively short order. Maybe a few months, maybe a year, depending on how often you use the microwave. The current rating does not mean you can open the circuit under load as much as you want. Especially with motors, this causes an arc across the contacts, eroding and pitting them severely in a small number of cycles.

There is an energy guide tag saying 310 KWhr/year. Nothing else. Detail info might be at the back of the fridge. Too heavy to pull the fridge out when loaded.

We just need to agree that it's too much to have both the fridge and microwave running together.

Yes, rating plate at the back of the microwave.

5 to 10 times per day. 3000 per year. It should last at least a year. I will put a filter cap in parallel with the contacts.