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Single line set on 1A2

Started by poplar1, October 01, 2013, 05:01:29 PM

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poplar1

Single line sets can usually be modified for use on 1A2 key systems by "robbing" one pair of the hook switch contacts to use as "A" lead control. This is necessary not only to show the line in use but also so that when you answer, the flashing lamps on all sets change to steady and the common audible ringer is silenced while the interrupter returns to "home" position.

Without the A lead control, other people won't see that the line is in use, and may try to access the line you're on from their multi-line phones. And the line may* go on hold when, discovering the line in use, they hang up. This may make it more difficult for you to hear on the single line set while the line is on hold.

Also, if on the unmodified single line set, you try to "pick up" a call held from another phone, you won't be able to get it off hold. So, others will think that you never picked up the call.
"C'est pas une restauration, c'est une rénovation."--François Martin.

Babybearjs

check the BSP's on this, the wiring diagrams show how to have the phones properly wired.... all my 500 series phones are wired for key equipment, including all my design line phones.... all the jacks require all 4 wires....
John