Test Products International 126 - Manual (Page 15)

15
b. MEASURING AC VOLTS
CAUTION!
Do not attempt to make a voltage measurement
if a test lead is plugged in the A or µmA input
jack. Instrument damage and/or personal injury
may result.
WARNING!
Do not attempt to make a voltage measurement
of more than 750V or of a voltage level that is
unknown.
Instrument set-up:
FUNCTION BLACK RED MINIMUM MAXIMUM
TEST LEAD TEST LEAD READING READING
V COM V Ω 0.001V 600V
Measurement Procedure:
1. Disconnect power to the circuit to be measured.
2. Plug the black test lead into the COM input jack.
3. Plug the red test lead into the V
Ω
input jack.
4. Set the rotary switch to the V function depending on
the voltage to be measured.
5. Connect the test leads to the circuit to be measured.
6. Reconnect power to the circuit to be measured.
7. Read the voltage on the 126.
14
Application Notes
When measuring the AC voltage of a standard
household outlet, remember that the small
rectangular hole is hot, the larger rectangular hole
is neutral and the round hole is ground.
To disconnect power from the outlet, find the fuse or
circuit breaker that controls the outlet and turn it off.
Set up the meter following the steps under
“Measurement Procedure” on page 13.
Then proceed with the following:
• Connect the red test lead to the hot side of
the outlet and the black lead to the neutral
side of the outlet. Reconnect power to the
outlet and read the voltage on the meter.
The reading should be approximately 110V
to 130V.
• Disconnect power from the outlet and
move the red wire to the ground hole.
Reconnect power to the outlet and read the
voltage on the meter. Typically less than
20V should exist from neutral to ground. If
110V or above exists, the outlet may be
wired incorrectly.