Amp Breaker is Tripping. Would the Amount Of Appliances Going do That? And is 30 Amps reasonable?

Question

Currently living in an old New York City apartment and our 30 amp breaker keeps tripping. I called in the electrician and he did a voltage test. He said that we were using too many appliances. My roommates seem to have a lot of / some pretty large appliances plugged in, so I'm guessing that's the reason. However I want to make sure that the appliances we have on should be enough to trip them, so I'm asking here. The apartment is about 1,100 square feet. Also, apologies if I'm giving the wrong unit. I don't know electrical work very well at all.

The box for the apartment is rated for 125 amps.

They 12,000 BTU air conditioners in rated at 9.7 amps in each of their rooms. They're both set on temperature controls, so they continuously cycle and power off and on. One also has a minifridge going that's rated at about 1 amp, and our main fridge in the living room is rated at 1.2 amps. My AC is is rated at 5,000 BTUs (4.5 amps). We also have various smaller appliances (kettle, small microwave, etc...), but they're not on continuously and they don't trip the breaker when I turn them on (though the vaccum does, but not in my room it seems). They also both have air purifiers going.

It's been incredibly hot recently so the AC's are working hard. I'm guessing that their overkill air conditioners are cycling on and off to keep the temperature consistent in their and when they both cycle on at the same time, the power draw spikes up. That, plus mine running consistently trips the breaker.

Would that be enough to do it, or is there something more serious up? It's tripped twice today and I'm tired of having to go flip it again and again. And if that's not enough to do it what could it be? Faulty wiring? Someone else stealing our power?

Answer 1

Yes, you could be exceeding the 30A limit for the apartment's master breaker. ACs generally draw the most power when starting up, so your average load may be acceptable but peak load may not be. Look up the starting/running current demands of everything you have plugged in and likely to be running at the same time, add them together, and I'll bet you are over 30A.

In one place. I had a circuit that would blow if my stereo and shop vac were both plugged into it and turned on. Learned to turn off the music when cleaning the living room.

Unless you can convince the landlord to upgrade your electric, all you can do is upgrade your equipment (new ACs are a lot more efficient than decades-old hand-me-downs, ditto refrigerators if you own one rather than it having come with the apt), LED light bulbs use a out 1/6th of the power incandescents do), or try to minimize other power usage during air conditioning weather.

Answer 2

OK, so you have a 30A branch circuit breaker feeding 120V receptacles powering a number of A/C units, some quite hungry.

You've already gone too far

Normal 120V bedroom receptacles are placed on 15 amp, and sometimes 20 amp, circuits per NEC 210.21(B)(3). They are not allowed on 30 amp circuits.

So the wire in your walls is certainly 15 amp rated and you are running it 100% over spec, or 20A rated and you are running it 50% over spec. An electrician could tell for sure.

Either you, or someone before you, enlarged this breaker from 20 to 30 amps without thinking about the consequences. And possibly someone before them enlarged the breaker from 15 to 20 amps.

An electrician needs to correct this ASAP before tragedy happens.

Those large A/Cs need dedicated circuits.

I suspect these are "portable" A/Cs, which actual perform very poorly and deliver as little as half the stated BTUs of cooling. Less, really, since they spend some time stopped because their tank is full. Technology Connections discusses this at length here.

Anyway yes, the answer is to bring in an electrician and have them run additional circuits to support those 11 amp air conditioners.

Another option is to switch to the vastly more efficient window units, but the 30 anp breaker on a 15-20A circuit still needs to be addressed.

Answer 3

It would seem that everyone replying here does not recognize the reality that tenants in old NYC apartments (not this guy but any of the previous) replace breakers with larger ones to allow circuits to run stuff... especially AC's and fridges.

hot weather, comfort, and human nature override the NEC.

you said I don't know electrical work very well at all along with i am guessing... so all your posted numbers I don't take to be valid. Only thing I would consider is if you posted a straightforward list every appliance and the make/model number or each that I could look up and then determine mathematically if that is the likely cause... your first sentence basically gives you the answer - old NYC apartment = yes you are using too many appliances. you are getting away with not tripping the breaker sometimes because you're plugging in a vacuum or whatever than everything that's on that one 30A breaker that keeps tripping.