Greenlee 77M-G Instruction Manual page 6

Identifying Tip and Ring (Polarity Test)
Telephone service must be present to perform this test.
In the OFF (4 VOLTS) position, connect the black test lead to
ground and the red test lead to each side of the line to be tested.
• A green LED indicates correct polarity. [The red test lead is
connected to the ring (negative) side of the circuit.]
• A red LED indicates reversed polarity.
• A red and green flickering LED (appears yellow) indicates the
presence of AC, or a ringing line.
Note: If independent ground is not available, connect the test
leads across the pair. The LED will be green when the red test
lead is connected to the ring (negative) side of the circuit and the
black lead is connected to the tip (positive).
Indicating Line Condition
Telephone service must be present to perform this test.
In the OFF (4 VOLTS) position, connect the red test lead to the
ring side of the circuit and the black lead to the tip.
• A bright green LED indicates a clear working line with correct
polarity.
• A bright red LED indicates a clear working line with reversed
polarity.
• A dim green LED indicates a busy (off hook) line or faulted line
condition (with correct polarity).
• A dim red LED indicates a busy (off hook) line or faulted line
condition (with reversed polarity).
• A brightly flickering green and red LED indicates a ringing line.
Verifying Lines
To perform this test, the test sets must be in the OFF (4 VOLTS)
position. Dial the line to be verified. Connect the red lead to the
ring side of the circuit and the black lead to tip. The LED will
flicker red and green. To confirm identification, monitor the line
and switch the tester (briefly) to the SHORT position. This will
terminate the call.
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