Megger Baker DX, User Manual

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Troubleshooting
130 Baker DX 71-030 User Guide EN V10 www.megger.com
CAUTION: D
O NOT USE ABRASIVE CLEANERS OR CHEMICALS TO CLEAN THE SCREEN
. S
TEEL
WOOL OR SANDPAPER WILL DESTROY THE MONITOR SCREEN
.
 Doing high-voltage testing with a printer attached to the printer port.
The surge pattern seen may show distortion from the interference. Additionally, it is
possible to damage the printer port with the 30 and 40 kV power packs. Quite high levels
of RFI/EMI may generate when the power pack is doing a Surge test. Print the results after
you complete your testing; doing so will prolong the instrument’s service life and any
peripheral devices, such as printers or laptops/personal computers.
Service: What to do First
Sometimes, issues arise that have simple solutions that you can resolve on your own, negating
the need to return a unit may. Please perform the following checks to determine whether you
have such an issue before returning the unit to Megger Baker Instruments.
DC Test Display Checks
If no voltage or current shows, one of three problems might exist:
 The item being tested is in fact faulty and has either low insulation resistance or open
connections
 The tester has an internal problem

The tester has a test lead problem, as described above for an open condition
Disconnect the test leads from the motor and isolate the tester from any grounded surface.
Reduce the output to minimum and run a DC test with an open lead condition. The display
should indicate a rising voltage trace. The current trace may rise slightly, but fall back to zero
when stopping the output increase.
NOTE: It is not necessary to run the output control at a high level to determine if the DX is working properly.
If the display still shows
no voltage trace
, call the Service department. Use a meter to confirm
the insulation resistance of the device being tested.
Test current trace operation by shorting test lead 1 and the ground lead together. Under this
condition, the voltage trace
will not move off the zero line and the current trace should rise
very rapidly and activate the DC test overcurrent trip. If the DC overcurrent trip does not occur,
check for open test leads at either test lead 1 or the ground lead (refer to Open condition
display ). If the problem persists, contact the Service department.
Open Ground Check
The open ground warning prevents testing. Answer these questions:
1.
Has the unit recently been moved to a new location with possibly an ungrounded
outlet?
2.
Is the unit operating in a situation where the AC power source is unknown?
3.
Is the unit operating on a scope cart that has its own outlet or power source?
4.
Is the unit operating using a two-wire extension cord?
5.
Is the unit operating on a transformer isolated circuit?