2 phone line polarity, 3 isolating noise problems, Bypass switch – DoorKing 1812 Plus User Manual

Page 44: 1812 terminal, Surge suppresser

Advertising
background image

5.2

Phone Line Polarity

C.O. (Phone Company)

C.O. (Phone Company)

Phone In

Phone In

Phone Out

Phone Out

Home

Home

8

6

7

3

1

5

4

2

Bypass

Switch

DC Positive

DC Positive

DC Positive

DC Positive

DC Negative

DC Negative

DC Negative

DC Negative

1812
Terminal

1

3

2

4

5

Phone In

Phone In

Phone Out

Phone Out

Ground

DC Positive

DC Positive

DC Negative

DC Negative

Check polarity on terminals.
Example: set a VOM meter to measure DC volts.
Place the positive lead on 1812 terminal 2 and the
negative lead on 1812 terminal 1. If the meter shows
a positive voltage - OK. If the meter shows a negative
voltage (needle moves off scale to the left), reverse
the wires. Repeat this process to check other wire
pairs on bypass switch and 1812 terminal strip.

Dashed lines are existing circuit board
connections and are shown for clarification purposes
only. DO NOT add any additional jumpers to wiring
or terminals.

When connecting multiple 1812 systems, maintain
common polarity on all connections.

When troubleshooting 1812 operational problems,
check phone line polarity. Crossed polarities can
affect system operation.

Ring

Tip

Ring

Tip

Gnd

Gnd

Surge

Suppresser

White/Blue

Blue/White

Central Office (C.O.)
Demarcation Device

Green

Red

Wiring if surge
suppresser is
not used.

Earth

Ground

White/Blue

Blue/White

Page 44

1812-161-E-1-10

Advertising