Megger Baker DX, Руководство пользователя

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Troubleshooting
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
There is no dampened sinusoidal wave pattern on the display when Surge
testing a coil. The wave pattern rises on the left and then slowly drops as it
trails off to the right of the screen. It may or may not cross the zero/ base
line.
The coil under test is probably too high of an impedance to get a good working pattern.
The coil may be very high in resistance and turn counts. The inability to perform a Surge
test on this coil, or group of coils in series, will remain unless you can break them down to
smaller units of lower impedance.
A broken test lead or poor connection might be the cause. Recheck connections, or try
using a different test lead selection (for example, lead 2 or lead 3). Under heavy use, check
test leads weekly to make sure that there is no breakage. Grasp the boot and clip in one
hand while pulling on the lead with the other hand. A broken lead will stretch, whereas a
good lead will not.

Open ground detected.
The instrument has an earth ground safety detect circuit. In certain situations, such as
aboard a ship, the detector may discover there is no safety ground present. You can disable
the detector in the settings menu.

How to test using the instrument with a generator to supply AC power at a
remote site.
Baker Surge testers can be powered by generators, but some proper grounding must be
done beforehand.
Start by following all accepted electrical and safety practices when working with a
generator’s output. The output is often floating; that is, no ground is made at the
generator. An appropriate ground—such as a service entrance ground—should be made at
the generator output panel. This ground is then available as a personnel safety ground to
ground all objects that the generator drives—including the Baker DX tester.
Alternatively, an isolation transformer (of appropriate VA rating) may be used between the
generator and the Baker DX. An earth ground is made on the isolated secondary side of
the isolation transformer, which is then available to properly ground work surfaces and test
equipment—including the Baker DX.

Test lead clips open.
With the unit in RLC test mode, connect an ohmmeter to the high-voltage test leads. Each
lead should read less than 10 ohms to any other high-voltage test lead on the tester.
 How and why to test from the motor’s star point.
When testing very large, high capacity motors, it may be impossible to reach the desired
test voltage. Wye-wound machines usually have an externally-connected star point. It is
often possible to apply 25–50 percent more voltage to a single-phase of a winding, if you
disconnect it at the star point and test end to end. The downside is the fact that you need
to break the connection and re-tape after the test. The upside is you can use a smaller,
lighter, less expensive tester to perform tests on a larger selection of equipment.

Cleaning a dirty display.
Use a water-dampened, soft, clean cloth (cotton) to gently wipe the LCD touch screen.