ABB Switzerland Ltd REG 316*4 1MRB520049-Uen / Rev. B
4-20
Procedure:
· Test conditions: machine at rated speed with excitation and
on load, grounding test switch ES open.
· Interrupt the REG 316*4 tripping circuits.
· Set the voltage on the REG 316*4 as measured according to
Section 4.2.3.5.3.
· Close the grounding switch ES.
· Slowly reduce the voltage setting “U-Setting” in steps until the
protection trips.
Caution: The tripping signal is delayed.
· Connect the test resistor R
P
to the minus pole of the excita-
tion circuit and repeat the above procedure.
· Measure and record the voltage across terminals 1 and 2 of
YWX111-11/-21 during the test.
· After the test has been completed, open the grounding switch
ES and close the REG 316*4 tripping circuits.
Checking the calibration of YWX111-11/-21
Measure the voltage across the bridge at terminals 1 and 2 of
YWX111-11/-21 with the machine running on load with excita-
tion. The reading should be
£ 150 mV
r.m.s.
in normal operation
(ES open). If it is higher,
· check the contact resistance of the shaft grounding brush
(see Section 4.2.3.6.).
· repeat the calibration of YWX111-11/-21 according to Section
4.2.3.5.2.
Note: It is possible that the 150 mV
r.m.s.
will not be reached in
the case of schemes with shaft filters and increased
YWX111-11/-21 sensitivity (R9 = 1 k
W).
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