2
#61-156
#61-157
#61-158
SureTest
®
Model ST-1THD & ST-1THDC
Instructions
Introduction
The SureTest
®
family of Circuit/distortion analyzers
identify problems common to electrical circuits and
harmonic distortion quickly, easily and accurately.
They have a patented voltage drop test, which applies a
full 15-ampere load without causing interruption to
equipment on the circuit. This family also features 64K
of memory to store and recall up to 36 hours of testing.
Product Features
• Identifies and Locates
Loose Wire Connections
Bad Splices/Receptacles
High Resistance Grounds
False (Bootleg) Grounds
Shared Neutrals
• Verifies
Proper GFCI Operation
Dedicated Circuit Presence
Isolated Ground Presence (with the 61-176 Adapter)
• Measures
True RMS Line Voltage
Resistance of Hot and Neutral Conductors
Ground Impedance
% Voltage Drop by Conducting an Actual Full 15 Amp Load Test
% Voltage Drop by Simulating a 20 Amp Load Test
GFCI Trip Time
True RMS Neutral-to-Ground Voltage
Estimated Load on Circuit
Line Frequency
Power Consumption Power Factor
% Total Harmonic Distortion (THD) in the Line Voltage (to the 31st
Harmonic)
Product Features
• Measures
% THD in the Neutral Current (to the 31st Harmonic)
True RMS Current with the 61-181 Clamp Adapter (ST-1THDC)
• Event Recording
Captures up to 36 hours of testing
Min/Max/Avg/Peak Line Voltage
Resistance in Hot, Neutral, and Ground Conductors
Min/Max/Avg/Peak Neutral-to-Ground Voltage
% THD in the Line Voltage and Neutral Current
% THD per Harmonic up to the 31st Harmonic
Line Frequency
General Operation
The SureTest Models ST-1THD and ST-1THDC Circuit/Distortion Analyzers
take only seconds to test each outlet and circuit under a full load. The
ST-1THD features two easy to use operating menus. The Wiring Menu
gives access to measurements of line voltage, voltage drop at a full 15
amperes and 20 amperes, ground-to-neutral voltage, resistance of the hot a
neutral conductor, ground impedance. A ground fault circuit interrupter
(GFCI) test is also performed that will disrupt the electrical supply if a func-
tional GFCI is present.
The Wave Form Menu gives access to measurements of % line voltage total
harmonic distortion (THD), line voltage harmonics to the 31st harmonic, %
neutral current THD, neutral current harmonics to the 31st harmonic and
line frequency.
In addition to these two programming menus, the ST-1THDC features a third
menu when used with the #61-181 Amp Clamp Adapter. The Clamp
Adapter Menu gives access to measurements of True RMS current, THD,
and harmonics to the 31st harmonic.
Any discrepancies from a normal reading indicate that a problem has been
detected in the circuit.
For use in 3-prong (grounded) outlets, inset the ST-1THD into the recepta-
cle with the ground pin extended. For use in 2-prong (non-grounded) out-
lets, leave the ground pin retracted. In non-grounded (2-prong) outlets
many of the tests will be non-functional due to an absence of ground.
