pdf 500 Series Desk Telephones, 500ABMW I1 Wiring Diagram Popular

Published on 05 December 2010 Modified on 11 June 2018 4123 downloads

Issue 1, undated.   Applies to 500AB.  (M = modular, W = without Bell System markings)  Sets sold outside the Bell System were not covered in BSPs, but were supplied with one page wiring diagrams inserted in the box with the phone.  See BSPs for the 500AB and 500ABM for other details.

Single line for 2-wire or 4-wire circuits.  Comes wired for 2-wire service but may be converted at installation to 4-wire service.  Arranged for but not equipped with a KS-8109L2 Buzzer.  Intended for use in 1A1 and 1A2 Key Telephone Systems and 3B Speakerphone Systems, however it is intended for specially engineered lines.  Not for general telephone use. (The touchtone version is 2504.)