Emerson MPR25 Switch User Manual


 
Installation and start-up procedures 67
25A Switch Mode RectifierNT5C06B / C Installation and User Manual
Low voltage alarm (LVA) adjustment
Procedure 18 - Low voltage alarm adjustment
Step Action
1 Turn the test potentiometer counterclockwise until the voltage reading
on the meter is -47 V. Turn LVA potentiometer R20 (located below the
LVA LED) clockwise until the LVA LED lights up, or counterclockwise
until it extinguishes.
2 Reinstall the LVD unit faceplate removed in Procedure 17.
–end–
LVD/low voltage disconnect / reconnect (LVDR) adjustment
WARNING
Do not switch the NORMAL/BYPASS switch back to the
NORMAL position if the LVD/LVDR potentiometers are
readjusted and their adjustments are not completely verified.
Doing so can cause loss of power to the load.
Note 1 :
To ensure that the potentiometer is turned fully
counterclockwise, the pot must be turned 20 full turns, or
until a click sound, emitted by the pot's clutch, is heard.
Note2 :
The effect of the LVDR potentiometer in setting the
reconnect voltage level is approximately 1.6 V for each
turn for Rel. 2 and 2A, or approximately 0.75 V for Rel. 3
and 3A. The connect/disconnect voltage difference is
smaller when the LVDR potentiometer is turned
counterclockwise and larger when it is turned clockwise.
Procedure 19 - Low voltage disconnect/reconnect adjustment
Step Action
1 Turn the LVD and the LVDR potentiometers fully counterclockwise.
2 Turn the LVDR potentiometer four turns clockwise for Release 2 and 2A,
or 9 turns for Release 3 and 3A.
3 Adjust the voltage measured at the test jacks to -43.5 V with the Test
potentiometer.
4 Turn the LVD potentiometer clockwise until the LVD LED lights up.
continued