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NetGuardian 832A to 864A 66 Block Amphenol Wiring Guide

When you purchase an RTU and 66-block from DPS, the block is pre-wired for the RTU purchased, and the proper amphenol cables will be provided. This guide will help you if you are:

  • Re-wiring for a NetGuardian 832A to 864A upgrade
  • Wiring for a NetGuardian 864A
832a to 854a Wiring

First of all, here's how a 66 block works: A 66 block is an older style telephone distribution panel. Even though it is an older technology, it is still widely used. It works by distributing incoming phone lines to all phone jacks in your facility.

The Differences Between 832A and 864A Wiring

The 832A features single RTN pins for each point; each alarm consumed two pins on the 66-block Amphenol, one for the alarm, one for the return/ground (RTN) path. To increase the discrete alarm capacity for the 864A, alarms each use only one pin on the Amphenol and are tied to a single, common return pin. Pins 1-24 and 25-32, which were the RTN pins for alarms 1-24 and 25-32 on the 832A will become even-numbered alarms, pins 2-64, on your 864A model NetGuardian.

When rewiring 66-blocks for use with an 864A, you will use a single row per alarm, rather than two, with all points tied to a common ground (See Figures A and B below to alarming differences between the 832A and 864A). If using a split 66 block, you will tie all points to the ground on row A25. If using a straight 66-block, you will tie your alarm points to the common ground on extra, separate 66-blocks.

832a to 854a Figure A

Figure A: A single point on the NetGuardian 832A consumes two pins on the amphenol and a pair of 66-block rows.

832a to 854a Figure B

Figure B: Each alarm on the 864 takes up only one pin on the amphenol and half a 66-block pair, tied to GND on row A25.

Note: DPS Telecom recommends terminating alarms for NetGuardian 864A units with split 66-block termination.

Things to Consider

Are you using Straight or Split 66-blocks?

If terminating alarms with split 66-blocks, you will need two blocks, one for each amphenol. A split 66-block means that the two terminals on the left side of the block on each row are electrically isolated (split) from the two right terminals.

If terminating alarms with straight 66-blocks, you will need four total blocks, two for each amphenol.

832a to 854a Figure C

Figure C: A 50-pin split 66-block with rows labeled A1 - S25.

How to Terminate a 66-Block

  1. Remove bridging clips on alarm rows.
  2. Remove clips on rows A1-S24 on the block joined to the first amphenol.
  3. Remove clips on rows A1-S8 on the block joined to the second amphenol.
  4. See Figure C for an example of a split block without bridging clips and rows labeled.
  5. Connect the alarm return path to row A25 on your block.
  6. Bridge the center terminals on row A25 of your block.
  7. Row A25 now constitutes a common return path for your discrete alarms.
832a to 854a Figure D

Figure D: Ground termination on a split 66-block for the NetGuardian 864A.

  1. Wire row A25 to the left terminal for discrete alarm rows.
  2. On the block tied to the first amphenol, wire the RTN path to rows A1-S24.
  3. On the block tied to the second amphenol, wire the RTN path to rows A1-S8.
  4. Connect wires to your alarms (may require a punch down tool).

Your 864A 66-block should be wired as shown in this diagram:

832a to 854a Figure E

Figure E: 66-block diagram for discrete alarms 1-48 on the NetGuardian 864A.

832a to 854a Figure F

Figure F: 66-block termination diagram for discrete alarms 49-64 on the NetGuardian 864A.

For Straight 66-Block Termination

Note: Because rows on a straight block are not electrically separate, you cannot terminate both the return path and alarm on the same row of a straight block. For straight block termination to an 864A model, you will need four total blocks, two for alarms and two extra blocks to denote the return/ground path. See Figure G at the end of this documentation for an example of straight 66-block wiring.

  1. Disconnect the return path for all alarms.
  2. You will reconnect the return path to your gear on another block.
  3. Connect two new blocks to the return/ground path.
  4. Connect a single row to the return/ground path.
  5. Bus rows A1-A25 together.
  6. You will not connect these blocks directly to the 864A unit.
  7. Connect your Return path blocks to your alarm blocks.
  8. Connect rows A25 on the ground blocks to row A25 on your blocks terminating alarms. See Figure G for an example.
  9. Reorganize alarms on your original two blocks.
  10. Re-wire each row accordingly and in order. (The diagrams above, discounting the RTN bus, show the order of alarms, 1-48 and 49-64). Note that each alarm will move up several rows equal to the alarm number minus 1.
832a to 854a Figure G

Figure G: Straight 66-block diagram for wiring alarms on a NetGuardian 864A.