Electrical Industry Canada: Test & Measurement Issue - 13

TEST & MEASUREMENT SAFETY CONSIDERATIONS CNT'D.
Causes of arc flash and shock include: loose panel wiring, screws or
fasteners that fall into an unsecured panel against a live bus, hand tools
shorted across two phases, incorrect test probes, misuse of
measurement stools.
With respect to the latter, Geeting says issues occur when,
" Measuring across phases with an inline amp meter, creating a short
circuit. Measuring continuity on a live circuit with a tool that cannot
withstand full voltage. Accidental shorting of phases with a test lead tip
that is too long of the safety category. "
When detecting the absence of voltage, often the first device used is
a non-contact voltage detector. Even though you are not physically
touching equipment the appropriate CAT rating needs to be observed
and PPE still needs to be worn.
To verify it is operating properly, Geeting notes, you should use the
live-dead-live method by finding an associated live circuit to test and
verify the operation of the meter, then " Go into the target circuit, which
we're assuming are de-energized and are looking to make sure that it is
dead or de-energized. And then we go back to the live circuit again. "
" The idea is, obviously, I'm trying to have 100% confidence that circuit
is in fact de-energized. And this is the easiest way to figure that out and
know that my meter is working and telling me the truth. "
There are instances where you won't have a reference point to verify
the tester. There are handheld units that provide a regulated/fixed AC
or DC output voltage, which can be used to verify testers, as well as
multimeters and clampmeters.
Test leads may be the biggest weakness in your multimeter systems.
Something as simple as wrapping them around your meter can cause
issues, " If you keep pulling on the leads in any direction and wrapping
them around your meter tightly, you're basically going to be breaking
the small conductors inside those wires, " says Geeting.

ELECTRICAL INDUSTRY CANADA

It's important to confirm the meter has shrouded connectors and
finger guards, the insulator is not pulled away and the probe tip isn't
loose, broken, or blown off. Along with ensuring the meter is
appropriately rated and designed for the application.
It is also worth noting a few best practices that have been echoed
throughout this handbook... work on de-energized circuits whenever
possible. Maintain your tools and PPE. If possible, don't work alone.
Connect the grounded lead, then hot and disconnect the hot lead
before the grounded lead. Use live-dead-live test method. Often, the
most obvious things are the easiest to overlook. The importance of
reviewing and following basic procedure and being diligent about the
best practices you've developed throughout your career can't be
overstated.

VOLUME 1, ISSUE 1

13
Electrical Industry Canada: Test & Measurement Issue

Table of Contents for the Digital Edition of Electrical Industry Canada: Test & Measurement Issue
