Is the circuit breaker amperage the rms amperage

In summary, the conversation discusses the circuit breakers in a house and their 15a rating, as well as the rms voltage and peak voltage. The individual is curious about the effect of connecting the terminals with a 10 ohm resistor and whether the breaker would trip. They also question if the amperage drawn is total amps or amps at the rms voltage. The conversation then refers to a datasheet that explains the concept of RMS current and how it relates to fuses and thermal breakers. The conversation concludes with thanks to those who provided information.
  • #1
Puglife
157
2
The circuit breakers of my house say that they are 15a (the majority of them). The rms voltage is 120v for the outlets, and so the peak voltage is about 170v. I was wondering, if I hypthetically connected the terminals together with a 10 ohm resistor, would the breaker trip? I don't know if the amperage drawn is total amps, or amps at the rms voltage, and so that is what I am asking. I know its not safe to do, and I am not going to do it, but I would like to know if it is 15a in general or at the rms, allowing for more amperage at its peak voltages. Thank You.
 
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  • #3
Grinkle said:
http://static.schneider-electric.us/docs/Circuit Protection/Molded Case Circuit Breakers/0100-400 A Frame FA-LA/FA-FC-FH/0600DB0105.pdf

Look at page 2, it has a curve of time at rated current vs trip time. A circuit breaker will take approx 1000 seconds to trip if the current is right at the rated value, according to this graph at least.
Im not exactly sure what it is saying, because no current will be consistantly be drawn out of the outlet, because many times a second, the voltage reaches zero, and thus so is the current.
 
  • #4
Puglife said:
Im not exactly sure what it is saying, because no current will be consistantly be drawn out of the outlet, because many times a second, the voltage reaches zero, and thus so is the current.

Puglife said:
I don't know if the amperage drawn is total amps, or amps at the rms voltage, and so that is what I am asking.
The datasheet Grinkle linked describes RMS symetrical current.

Look up "RMS current"
then think about it - fuses amd thermal breakers work by heating an element.
Not surprising they'd be rated in terms of "heating value" of current, would you think ?
 
  • #5
Thanks, Jim - yes, RMS.
 
  • #6
Grinkle said:
Thanks, Jim - yes, RMS.
Thank You Both!
 

What is the difference between circuit breaker amperage and rms amperage?

The circuit breaker amperage refers to the maximum amount of current that a circuit breaker can handle without tripping. It is typically labeled on the circuit breaker itself and is determined based on the wire size and the load of the circuit. On the other hand, rms amperage stands for root mean square amperage and is a measure of the average or effective current in an alternating current (AC) circuit.

Is the circuit breaker amperage the same as the rated amperage?

No, the circuit breaker amperage and the rated amperage are not the same. The rated amperage is the maximum amount of current that a device can safely handle, while the circuit breaker amperage is the maximum amount of current that the circuit breaker can handle before tripping. The rated amperage is usually higher than the circuit breaker amperage to allow for temporary surges in current.

What happens if the circuit breaker amperage is lower than the rated amperage?

If the circuit breaker amperage is lower than the rated amperage, it can cause the circuit breaker to trip frequently, as it will be unable to handle the amount of current flowing through the circuit. This can also lead to overheating and potential damage to the circuit and devices connected to it. It is important to always use a circuit breaker with the appropriate amperage for the circuit's load.

Can the circuit breaker amperage be changed?

No, the circuit breaker amperage cannot be changed. It is a fixed value that is determined by the manufacturer based on the wire size and the load of the circuit. Attempting to change the circuit breaker amperage can be dangerous and can cause damage to the circuit and connected devices. If you need a higher or lower amperage for a specific circuit, it is best to consult a licensed electrician.

How can I determine the circuit breaker amperage for a specific circuit?

The circuit breaker amperage can typically be found on the circuit breaker itself or in the electrical panel. If you are unsure or cannot find the amperage, it is best to consult a licensed electrician. They can use specialized tools and knowledge to determine the appropriate amperage for the circuit and ensure it is safe and up to code.

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