Can anyone explain what the meaning of the suffix letters "B" and "L" are on Siemens breaker panels?

For example, what is the difference between SN2040B an SN2040L?

1 Answer 1


The difference is B = Main Breaker, L = Main Lug.

Ref: Siemens Product Literature page 8/9.

  • 1
    Can’t get more specific than that.
    – Ed Beal
    Jan 27 at 20:45
  • Sometimes a 2-line answer including a link is really all there is to it. And for those who complain about Big Orange, their website happens to be a great resource for finding product literature, though inconsistent - one panel product page will have the literature and warranty and installation PDFs and another (same brand) will have just the installation PDF, etc. Jan 27 at 21:03
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    Page "2" (actual 4) here decrypts the entire model number. Jan 28 at 1:53
  • @Harper-ReinstateMonica Correct with respect to the B vs. L issue. But that document does not actually list the SN part numbers. As it turns out (for obvious and expected reasons), B vs. L means exactly the same in both documents, but they cover different products. Jan 28 at 1:59
  • 1
    Yeah there's that. However in decrypting an SN I found they too conform to this format. Jan 28 at 2:03

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