Radio Shack 22-168A - Measuring AC;DC Current

© If you choose to make the measurements, use
extreme care. The actual voltage can be great-
er than the circuit's rated voltage (line-to-
ground).
© To determine the line-to-line voltage, multiply
the rated line-to-ground voltage by 1.732.
For example, if the rated line-to-ground volt-
age is 462 volts, the line-to-line voltage is:
462 Volts X 1.732=800 Volts
This voltage exceeds the meter’s rating and
you should not connect the meter to this cir-
cuit. See “Measuring High-Voltage Circuits.”
MEASURING AC/DC CURRENT
WARNINGS:
DO NOT APPLY VOLTAGE DIRECTLY
ACROSS TERMINALS. YOU MUST CON-
NECT THE METER IN SERIES WITH
THE CIRCUIT.
THE 20A TERMINAL IS FUSED. A SEVERE
FIRE HAZARD AND SHORT CIRCUIT DAN-
GER EXISTS IF YOU APPLY A VOLTAGE
WITH HIGH-CURRENT CAPABILITY TO
THIS TERMINAL. THE METER CAN BE DE-
STROYED UNDER SUCH CONDITIONS.
To measure current, break the circuit and con-
nect the probes to two circuit connection points.
Never connect the probes across a voltage
source in parallel. Doing so can blow the fuse
or damage the circuit under test.
Note: The maximum input current is 200 mA
or 20 A depending on the terminal used. In these
ranges excessive current blows the fuses, which
you must replace. 21