Am I violating the Code if I select a Bigger Breaker

[Electriman]

Dear friends,

As you all know we can select one size up breaker if 125% of continues+100% non continues loads fall between two standard ratings. for example, if the continues load is 37 A then 125% of 37 will be 46.25 A which is between 45 A and 50 A and I can select 50 A breaker to protect my circuit.

My question is what if I select a bigger size breaker for example in above example I select a 60 or 70 or even a 100 A breaker, am I violating the code provided that I size the cable according to breaker rating?

I think as long as I size the cable based on the breaker rating I am on safe side because the breaker is there to protect the cable not the load.

Thank you for your responses in advance.

 

[augie47]

You are correct as far as the breaker sized to protect the conductor. Keep in mind the load or device may also dictate the size of the overcurrent protection also. For instance, if your 37 amp load was an appliance, the maximum overcurent device would be regulated by 422.11 regardless of the conductor size.

 

[david luchini]

I agree with Gus.

Take a look at 240.3 for overcurrent protection requirements for equipment.

 

[Electriman]

Thank you for your responses.