ABB REG316 4 Series, Operating Instructions Manual

Page: 273 / 980

REG 316*4 1MRB520049-Uen / Rev. F
ABB Switzerland Ltd
3-235
Determination of ‘MTR’:
·
Ground the star-point (Rf = 0
W
).
·
Apply a logical ‘1’ to the binary input ‘AdjMTRInp’.
·
Open the HMC menu ‘Display function measurements’
and note the value for ‘MTR’. Return to the ‘Editor’ menu,
select the function ‘Stator-EFP’ in the sub-menu ‘Present
prot funcs’ and enter and save the value noted for the
‘MTR’.
·
Remove the connection between the star-point and
ground.
· Remove the logical ‘1’ from the binary input ‘AdjMTRInp’.
Determination of ‘Res’:
Select the menus and items as for ‘Determination of MTR’.
· Apply a logical ‘1’ to the binary input ‘AdjREsInp’.
·
Enter an approximate value for REs.
·
Simulate a ground fault Rf by connecting a resistor be-
tween the star-point and ground: 8 k
W
< Rf < 12 k
W
·
Open the HMC menu ‘Edit function parameters’:
Enter the value for the setting ‘RFs-Adjust’.
Enter the approximate value for ‘REs’. If the grounding
resistor is on the secondary system side, the value
entered must be referred to the primary side. (Refer also
to the Sections concerning REs and MTR in the case of
secondary injection at the star-point, respectively at the
terminals.) Save the settings entered.
·
Open the menu ‘Display function measurements’ and note
the value of ‘REs’.
·
Enter and save the value noted for the setting of ‘REs’ in
the ‘Edit function parameters’ sub-menu.
·
Remove the simulated ground fault.
·
Remove the logical ‘1’ from the binary input ‘AdjREsInp’.
The protection function will only switch back from the de-
termination mode to the normal protection mode when both
binary Inputs have been reset.
Check the settings by connecting resistors of 100
W
to 20 k
W
(P
³
5 W) between the star-point and ground and compare their
values with the readings of the measured values on the screen.