The Right way:
LINE----\               /-------Equipment
        | In            | Out
      +---------------------+
      | Bypass Switch / PDU |
      +---------------------+
        |               |
        |               |
        | In            | Out
      +---------------------+
      |         UPS         |
      +---------------------+
                 |
      +---------------------+
      |      Batteries      |
      +---------------------+

How $electrician wired it:
LINE                    /-------Equipment
  |     | In            | Out
  |   +---------------------+
  |   | Bypass Switch / PDU |
  |   +---------------------+
  |                     |
  \-----\               |
        | In            | Out
      +---------------------+
      |         UPS         |
      +---------------------+
                 |
      +---------------------+
      |      Batteries      |
      +---------------------+