Megger IDAX 300, Руководство пользователя

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AG033586EE ZP-AG03E IDAX 300/322/350 37
6 APPENDIX AERROR MESSAGES
▪
select another measurement configuration if
possible
2.
Measured capacitance lower than 10 pF.
Most likely no contact with specimen:
▪
check connections with specimen for loose contacts
▪
check measurement cables for damage
For more information of actual measured capacitance,
please see Message Window.
(366) Specimen capacitance above
limit
Measured capacitance above limit specified in test
plan by MaxSpecimenC.
Possible reasons and countermeasures
1.
Large size of test object results in high values of
capacitance:
▪
change limit set by MaxSpecimenC to an
approximately 10% higher value than measured
capacitance
▪
select another measurement configuration if
possible
▪
decrease in test voltage allows for measuring at
higher frequencies
(367) Measured DC current >
MaxDCCurrent
Measured DC current exceeds the limits set in test
plan by MaxDCCurrent.
Possible reasons and countermeasures
1.
The far most common reason is too low resistance
between measurement electrode and guard, e.g.
measuring a UST configuration between high and
low voltage windings of a two winding transform-
er, the low voltage winding has too low impedance
to ground (inductive voltage transformer con-
nected, internal damage of transformer, neutral
connected to ground via a Peterson coil. For a GST
measurement, same applies to guard electrode,
i.e. a too low resistance Guard electrode to ground
may introduce DC currents
▪
Make sure that floating electron has high resistance
to ground, if not possible use another setup (e.g.
measure to ground without use of guard)
▪
It is possible increase limit level for DC current in
Measurement Template, but only when difference is
very small and all other possibilities excluded
(368) Measured hum current >
MaxHumCurrent
Measured interference or hum current exceeds the
limits set in test plan by MaxHumCurrent.
Possible reasons and countermeasures
1.
Level of interferences is very high:
Try to reduce the interference level by
▪
Disconnect still connected bush-bars that pick-up
interference
▪
Select another set-up, e.g. a CHG+CHL is much less
influenced by interference compared to CHG
▪
As last option, it is possible increase the limit for
hum current in the Measurement Template