Can a 125Amp Circuit Breaker be used for 250Amps?
If a 2pole circuit breaker is rated for 125 amps can it be used for 250 amps? The Amperage Rating of a 2Pole 125Amp Circuit Breaker.© By: Dave Rongey
2Pole 125 Amp Circuit Breaker
Electrical Question: If a 2pole circuit breaker is rated for 125 amps can it be used for a total of 250 amps?
- I am trying to add to my circuit breaker and am a little lost. I have 2- 1/0 gauge “hot” wires (aluminum) going to my main breaker and from my understanding 1/0 gauge can handle 125 amps.
- The main breaker shows 125 amps on one side. So my question is can I run up to 250 amps (minus 20%) continuous current without modification or am I limited to 125 amps?
- I won’t actually be anywhere near 250 amps but I’m curious if I have more than 125 amps of continuous current available. I don’t know much about this and will not be attempting the work myself but I am curious if it’s possible.
- Also, when reading amperage ratings at the breaker box are they based on 120v or 240v?
This electrical wiring question came from Carl, in Castle Rock, Colorado.
Thanks for your electrical wiring question Carl.
The Amperage Rating of a 125 Amp Circuit Breaker
Application: Installing a Circuit Breaker in a Main Electric Service Panel.
Skill Level: Advanced – Should be Installed by a Licensed Electrical Contractor. This is Not Recommended for Homeowners or DIY individuals.
Tools Required: Electricians pouch of hand tools and the various power tools necessary for the specific method of electrical service installation.
Estimated Time: Depends on the type of panel, the location, and available access to the project area.
Precaution: Shock Hazard and Arc Flash Hazard! This is an extensive project which should be done by a licensed electrical contractor. The main source of electric utility power should be turned off before working in an electric panel.
Notice: Installing an Electrical Service Panel should be done according to local and national electrical codes with a permit and be inspected.
The Amperage Rating of a 2Pole 125Amp Circuit Breaker
NOTE: The two power conductors of a 2pole 240Volt electrical service are out of phase from each other when the power is produced at the generating station or the power source unit.
- The amperage rating of a 2Pole 125 Amp Circuit Breaker is based on each pole or wire conductor.
- The amperage rating for Pole One, often refereed to as Line 1 is 125amps.
- The amperage rating for Pole Two, often refereed to as Line 2 is 125amps.
- The combined amperage rating of the 2pole circuit breaker is still 125amps.
Note: Electrical circuits are carefully calculated and designed for the specific application or equipment which will be connected to the circuit.
The Amperage Rating of an Electrical Panel
- Each panel is designed for a maximum amperage rating based on voltage.
- A 120/240 volt panel has the capability of providing 1pole 120 volt circuits, or 2pole 240volt circuits.
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