Bell System 3640 Series Identification, Installation, Connections, And Maintenance

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BELL SYSTEM PRACTICES
AT&TCo Special
SECTION 529-236-120
Issue 4, February 1974
TELEPHONE SETS
3640 AND 3641 TYPES
IDENTIFICATION, INSTALLATION, CONNECTIONS, AND MAINTENANCE
1. GENERAL
(a) Intended solely for use with specially
engineered lines-not for general telephone
use.
ft
Do not attempt any installation or
connections of this equipment unless
the practice has been read and
thoroughly understood.
(b) This section is reissued to:
• Add the 66A3AD dial
• Add 661A key assembly
• Show 66A3A dial MD
2.
IDENTIFICATION
PURPOSE
The 3640- and 3641-type telephone sets are
multikey type sets which can be switched
between 2- and 4-wire telephone circuits by a
relay provided within the telephone set.
ORDERING GUIDE
Set, Telephone, 3640-type (Tables A and B)
Set, Telephone, 3641-type (Tables A and B)
(a)
Replaceable Components:
• Blank, Apparatus, 111A
• Cord, Mounting, D150P-87 (3640-type sets)
• Cord, Mounting, D250F-87 (3641-type sets)
• Dial, •66A3AD• (nonilluminated)
• Dial, 66A4B (illuminated)
• Faceplate (Table A)
• Strip, Designation, Form E-5253
• Card, Number, Form E-5002A
• P-90D012 Polarity Guard
• Handset, G3Y-*
• Key, 635A2C
• Key, 635C2C
• P-29E330 Collar (635 keys)
• Lamp, 51A (635 keys)
• Lamp, 53A (dial, exclusion switch, and 672A
transmitter)
• Mat (Tables A and B)
• Ringer, TlA or NlA
• Transmitter, 672A
• •661A• Key Assemb ly (exclusion switch)
• •840149975• Collar (exclusion key)
*Refer to Table B for color.
(b)
Replaceable Optional Components:
• Buzzer, KS-8109L2
• Buzzer, KS-20419Ll
(c) Loose Parts Furnished With Set:
• Mat-Silver and Gold (Tables A and B)
• 840157218 Contact Strip Assembly (one per
unu sed key module)
©
Amer ican Telephone and Telegraph Company, 1974
Printed in U.S.A .
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