3M C860, Руководство пользователя

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D-Series Intercoms
Technical Bulletin 1/22/98
1-98 Heavy Duty Security Handset Reliability Improvement
This modification reduces potential problems caused by the cradle switch contacts. It can be
used when the handset is used alone or with a separate speaker/mic and switch assembly. All handsets
shipped from our stock after July, 1998 have these updates . They can be recognized by a “07/98
Rev. C” sticker on the outside of the shipping box and inside the stainless cradle switch cover.
Advantages:
•
The handset audio is always on, eliminating potential audio failure from dirty, worn, or misaligned
switch contacts.
•
When the handset is in the cradle, the separate speaker/mic is connected by 2 switch contacts wired
in parallel, effectively doubling its reliability.
•
A 6-32 x 1 ¾” screw and nut are added to the terminal strip support plate preventing the plate from
flexing if the cables are improperly stuffed in the electrical box during installation.
Parts needed:
1 each, 10 micro Farad capacitor, 50 Volts, axial leads (Required for C5000 compatibility only)
1 each, 20 k Ohm resistor, ¼ Watt (Required for C5000 compatibility only)
1 each, 6-32x1 ¾” Phillips or slotted screw and nut
Procedure:
1. Remove the 4-40 Phillips screw from the lower right side terminal block and discard the screw.
Pivot the terminal and drill the hole to accept the 6-32 x 1 ¾” screw. Insert the new screw through
the block and plate and install the nut.
2. Remove the brown wire from terminal 2A. Connect this wire to terminal 1A
3. Remove the brown wire from terminal 4A. Connect this wire to terminal 3A
4. Cut the brown wire from terminal 8B near the end attached to S3. Strip back the insulation ¼” and
connect to terminal 1B.
5. Cut the brown wire from terminal 10A near the attached to S2. Strip back the insulation ¼” and
connect to terminal 2B. Remove the end of this same wire from terminal 10A and connect to 10B
along with the black wire from the handset.
Notes:
•
Cradle switches S1, S2 and S3 are shown with the handset off-hook.
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When more than 1 wire is connected to a terminal, twist them together first, then insert them into the
terminal.
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If outbound volume to the handset needs to be adjusted in relation to a separate outside speaker,
change the resistor value between terminals 8A and 9A.