Can You Tap 120V Off a 208V Circuit?

[Smart $]

It is not. Minimum circuit ampacity are branch circuit selection current are separate items.

Take a look at 440.32, for instance. MCA is determined by 125% of the RLA or 125% of the BCSC, whichever is greater.

Okay, so let me play devil's advocate here... :angel:

Where does nameplate MCA come into play in Article 440... or does it not and is simply compliance 110.3(B)?

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Also seems redundant for requirements such as 440.32 (there are several in Article 440) that state "the motor-compressor rated-load current or the branch-circuit selection current, whichever is greater." The definition in 440.2 states "The value of branch-circuit selection current will always be equal to or greater than the marked rated-load current." Seems to me it should be stated as "the motor-compressor rated-load current, or the branch-circuit selection current if so marked."

Nevertheless, I'm the same as you in that I've never seen a unit with BCSC on the nameplate... :happyno:

 

[david luchini]

Okay, so let me play devil's advocate here... :angel:

Where does nameplate MCA come into play in Article 440... or does it not and is simply compliance 110.3(B)?

____

Also seems redundant for requirements such as 440.32 (there are several in Article 440) that state "the motor-compressor rated-load current or the branch-circuit selection current, whichever is greater." The definition in 440.2 states "The value of branch-circuit selection current will always be equal to or greater than the marked rated-load current." Seems to me it should be stated as "the motor-compressor rated-load current, or the branch-circuit selection current if so marked."

Nevertheless, I'm the same as you in that I've never seen a unit with BCSC on the nameplate... :happyno:

MCA comes into play in 440.4(B) - "shall be provided with a visible nameplate marked with...minimum supply circuit conductor ampacity..."

I agree that the section is written oddly as "whichever is greater" when BCSC will always be greater than or equal to rated load current.