Xerox Document Centre 420 User Manual page 338

Select [Long Document].
Select [600 mm] or
[3600 mm] to enable
scanning of long documents
up to these lengths.
Select [Save].
Page 11-42
Long Document (DC440/432/430/425)
This feature allows the Key Operator to set up the machine to
scan and send fax documents that are longer than 16.5".
Xerox Document Centre 440/432/430/426/425/420 User Guide