AT&T System 25 - Manual (Page 303)

APPENDIX C: System Additions or Changes
Table C-A. Unit Loads
Port Type
I
Unit Load
ZTN178 port
I
0.5
TN742, TN746 1.0
port
ETU 2.0
TN760B Port 2.0
TN753B Port 0.5
502-type Headset .75
Adapter
5-Button
1.0
Terminals
Port Type Unit Load
10- and 34-Button 1.25
Terminals
HFAI Terminals 1.5
MET Terminals 1.0
BIS Terminals 1.5
34-Button Deluxe 2.0
Terminals
S102A 1.0
Speakerphone
34-Button BIS
2.0
With Display
Add Circuit Pack
All CPs are installed in the cabinets in the same way. Evaluate the cabinet unit
power bad, using the procedure above.
1.
2.
3.
4.
Determine in which cabinet to add the CP. Install all DID CPs in
Cabinet 1. A maximum of two Pooled Modem CPs can be installed in
each cabinet. A maximum of two TN767 DS1 Interface CPs can be
Installed per system. Select the cabinet with the lowest unit load to
minimize the power bad and heat dissipation requirements.
It the CP being added is a TN760B, you must first set the option switches
hr the type signaling. See Set TN760B Option Switches in this appendix.
Remove the front cover of the cabinet.
See Danger and Warning. Make sure that your hands are clean and dry.
Put on a wrist grounding strap, and clip it to the grounding block at the
back of the cabinet.
D a n g e r : Do not clip the wrist grounding strap to the front of
the cabinet where high voltage is present.
Caution: To release static electricity, always wear a wrist
grounding strap when handling CPs. Electrostatic
discharge can destroy or severely damage integrated
circuits and CPs.
C-2 November 1995