Operation Test - ABB BUE Maintenance Manual

3.10 Operation test

Operate the motor-drive mechanism, first with manual
operation and then electrically between the limit-positions.
Check the limit-stops by operating the tap-changer to one
of the end-positions. When trying to operate it electrically
beyond the end-position, the motor should not start. Check
the mechanical end-stop by trying to hand crank it beyond
the end-position. After a couple of turns on the hand crank,
it should be mechanically stopped. Hand crank back to the
end-position (where the indicator flag is positioned in the
middle for the BUE, and when the indicator flag shows white
color for the BUL2). Operate the tap-changer electrically to
the other end-position and carry out the same test procedure
as above.
Check the emergency stop by triggering a RAISE or LOWER
impulse and after about one second, press the emergency
stop. The operation should be interrupted. Reset the
emergency stop by turning the knob clockwise and switch
on the protective motor switch. The started operation should
now be completed.
Check the run-through protection with the step-by-step
function disengaged. This is done by first removing the
connection between terminals X4:1 and X4:2 and then
keeping the RAISE/LOWER switch engaged. The motor-
drive mechanism should stop before the fourth operation is
completed. This check must be performed at least five steps
from the end-position. After the test, reset the time relay by
setting the LOCAL/REMOTE switch to 0 and then back. Reset
the protective motor switch to ON. Reconnect the connection
between X4:1 and X4:2.
Check the step-by-step relay by keeping the RAISE/LOWER
switch engaged in RAISE. The tap-changer shall advance only
one step. Repeat the check for LOWER.
Check the function of the position transmitter and other multi-
position switches in all positions.
18 Maintenance guide BUE/BUL2 | 1ZSC000498-ABH en, Rev. 1