AT&T 540 Series Common Installation And Maintenance Information

BELL SYSTEM PRACTICES
AT&TCo Standard
SECTION 502-500-120
issue 5, August 1980
TELEPHONE SETS
540, 560, 1560, AND 2560 SERIES
COMMON INSTALLATION AND
1. GENERAL
1.01
This section contains information on
4-
and
6-button key telephone sets.
1.02
This section is reissued to:
Add information on the rotary dial 563HBMS,
564HLMS, 565GKMS, 565HKMS, 565LKMS,
and 568HAAMS telephone sets
Add information on the TOUCH-TONE" dial
2564HLMS, 2563HBMS, 2565GKMS, 2565HKMS,
2565LKMS, and 2568HAAMS telephone sets
Show the rotary dial 563HBM, t564HLM,
565GKM, 565HKM, 565LKM, and 568HAAM
telephone sets (MD)
Show the TOUCH-TONE dial 2563HBM,
2564HLM, 2565GKM, 2565HKM, 2565LKM,
and 2568HAAM telephone sets (MD).
1.03
When installing or repairing any telephone
set,
all
connections should be checked for
tightness in order to prevent trouble reports.
2. INSTALLATION
A. Keys
2.01
The 636-type key (Fig. 1) has a terminal
board arrangement to accommodate matching
cord terminal wafers, so that any line connected
to the set can be interchanged readily to appear
on any five line pickup keys. See Fig. 2 and 3
for terminal designations on the 636A and 636B,
respectively.
2.o2
Lamps associated with the buttons may have
common or individual grounds. See sections
MAINTENANCE INFORMATION
P
----
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Fig. 1—636A Key, Bottom View
covering connections of individual telephone sets
for lamp connections.
2.03
Certain pickup buttons on 6-button sets are
arranged for conversion to signaling. To
convert, remove 811218924 (P-12 A892) screw detail
(Fig. 1) and make necessary wiring changes. Table
A shows key and associated telephone sets with
convertible buttons.
2.04
Unused buttons, either round or square
style, may be blocked with an 811218585
(P-12 A858) blocking ring. Insert as shown in Fig.
4.
B. Lamp Retainer
2.05
In early telephone sets equipped with a 636A
or 636B key, the .51A lamp contact springs
are susceptible to loosing their tension. An adjunct
840362347 lamp retainer (Fig. 5) is available and
NOTICE
Not for use or disclosure outside the
Bell System except under written agreement
Printed in U.S..A. Page 1