Evaluation Engineering - 12

ELECTRICAL SAFETY TEST

socket hipot lead sets and ground bond
test lead kits, and a retractable tip test
pistol lead set.
Piotrowski said that to ensure operator safety, Ikonix offers personal protective equipment (PPE) accessories, including insulation mats, DUT interlocked
enclosures to ensure no contact to live
voltage, signal tower lights to notify operators when testing is in progress, test
probes to ensure minimum approach
boundaries, warning signs to post in
high-voltage testing areas, dual remote
palm switches to ensure that an operator cannot touch a DUT with live voltage applied, and applications consulting
and operator training on proper PPE and
equipment safe practices. Piotrowski
added, "We offer certifications for operators to ensure they are trained equipment users."

concerns. Our new 3600 series supports
this with an interlock connection which
will instantly stop the testing process
when engaged. Any normally open switch
connected to a door or gate, hand safety
switch, or other safety device will activate
the interlock. Ground-fault detection is
also available to stop the test if a short
to ground is detected."
Smith cited several GW Instek product features that enhance operator
safety. A zero-cross function turns off
the voltage within 150 ms if a test fails,
a safety-interlock feature prevents execution of test without first closing a
specific circuit, and a remote on/off
feature is available.
"Our newer GPT-12000 Series meets
IEC 61010-2-034 design requirements,
such as double insulation for input
and output voltage, safe output/warn-

GW Instek GPT-12000 electrical safety tester.

Other safety features include a built-in
equipment interlock with both software
controlled I/O port and connection to
hardware disabling output, Piotrowski
said. A SmartGFI feature monitors leakage to ground to ensure no shock hazard
posed to operator; if leakage exceeds set
value (0.1 to 5 mA), the instrument output is disabled.
According to Carter at Chroma, "All
of our electrical safety products feature
a safety interlock, and most of our products where applicable have a groundfault-interrupt circuit which will cut off
the output if the unit senses a current
imbalance."
Pederson at B&K Precision commented, "Operator safety is one of our top

EVALUATION ENGINEERING APRIL 2020

ing mechanism, post-test discharge
mechanism, as well as a safety interlock
feature to prevent execution of a test
without first closing a specific circuit
to ensure user safety during the operation," Smith said.

Trends
According to Pederson at B&K Precision,
safety standards have evolved along with
the testing methods and equipment used.
"Traditionally, a simple DC-only hipot
tester was all that was needed," he said.
"These testers typically employ a low current useful for testing capacitive DUTs.
In more recent years, AC hipot testers
have increased in popularity, bringing
with them several advantages: The AC

test signal stresses the insulation in
both polarities, discharging the DUT is
not necessary, and no voltage ramping
is required, to name a few."
Carter at Chroma put automation,
traceability, reliability, and test repeatability at the forefront of electrical product safety testing. "We see a strong trend
that more customers want a test solution
that can check all of these boxes," he said.
"A major part of our business is providing
automated test systems, and we pride
ourselves in our ability to deliver both
off-the-shelf and/or custom solutions for
our customer's exact needs."
Piotrowski at Ikonix also cited automation as a trend, along with data and
control, resulting from the move toward
IoT and integration with all forms of
production and manufacturing processes. "This trend includes analytics
to determine trends in passes/failures
and measurements of electrical safety
testing equipment integrated into the
overall manufacturing line for a complete picture of the production process,"
he said. "For example, a user could implement integrated software to talk to
multiple pieces of equipment (EST and
otherwise), upload all tests and data to
the system (or cloud), and analyze overall efficiencies in production."
Smith at Instek America Corp. cited
several trends in product safety test.
"Instruments must always have relevant
protection and safety warnings for the
test operator during test execution," he
said. He also cited an increasing need for
both manual/interactive operation and
remote operation/automated testing as
well as an increasing focus on test data
collection and storage and automated
statistical analysis supplied by the test
equipment. "Customers don't expect to
pay additional fees for software to do all
of the above," he concluded.
REFERENCES

1. Grodt, Steve, Decreasing Risk of Electrical
Shorts in Lithium Ion Battery Cells, White Paper,
Chroma Systems Solutions, 2020.
2. Clark, Kevin, Fundamentals of Electrical Safety
Testing, White Paper, Vitrek LLC, November 2018.

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