EATON ELECTRICAL
39
Predictive Diagnostics
2. IG display shows continuously 357 (reference
signal magnitude is too high).
3. Displayed values range e/-5
0
(low signal
magnitude or high noise).
4. Any change in displayed phase shift has not been
observed.
As default, the device is synchronized from its power
source. The device requires a phase shift between the
source and the phase-A voltage on the object to be
detected.
Phase shift can automatically be detected by the device
or entered manually if determined by any independent
tool (UPDA or oscilloscope).
Phase shift is the phase
between zero crossing of power source voltage and
the first correspondent zero crossing of the voltage
on the phase A of an object!
If the A-phase reference is unavailable, another phase
can be used, but manual adjustment will be required
after automatic detection. The following phase angles
must be added to the automatically detected value (pay
attention to signs):
B-phase
-120
0
C-phase
-240
0
A-B-phase
+30
0
C-B-phase
+90
0
Coupling Cap on A-phase
+90
0
If a result is out the range of 0–360
0
, you should add to
the result or subtract from it 360
0
in order to get it within
the range. This result should be entered in manual mode.
Example: Reference signal from A-B phase (open
delta PT) is used. Automatically detected phase shift is
345
0
. 30
0
= 375
0
. Subtracting 360
0
= +15
0
. 15
0
in case of internal Humidity sensor) must be temporally
disconnected.
•
Place temporal jumper between terminals 8 (“Ref.”) and terminal 12
(“S of H%”).
•
Temporally connect the phase A voltage signal of the object instead
of
Humidity signal on the Sensor Interface board
(terminals ## 6
- ground and 12 - signal).
Never exceed 5 V AC!!!.
In Revision 1 set switch in Sensor Interface Board to the right in “Ref”
position. This will bring power frequency signal from coupling
capacitor in the channel 1 to reference circuitry. You do not need to
account for any additional sensor phase shift!
Using potential transformer for phase shift measurement is described
in Appendix2. Note that Jumper J1 (shown in the figure 6.3a
Appendix2) should be removed.
For automatic detection
Press
Set
and wait until
PhSh-XXX
appears. The device is automatically
detecting the required phase shift between power source and the
reference signal and displays it. Write down every 15 seconds several
readings (>10) that appears on the display and calculate he average value.
If this average value is within +5
0
, setting is correct. If variations are
higher – high frequency noise is essential in the reference signal.
Press
Enter
to save new value, or
Esc
to exit without saving.
If
Enter
has been pressed, the device will store the last detected phase
shift.
For firmware 2.07 version only, subtract detected phase shift from
360Deg and use this number for all following procedures!
Restore original connections or set switch back to
“
H%”
position.
