Vertiv APM 0250kMK16FN02000, User Manual

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1. Manually turn off the inverter of each UPS in turn. The power flow diagram shows INVERTER OFF, and the
buzzer alarms. The load transfers to the static bypass, and the inverter shuts down. At last, all UPSs are
transferred to Bypass mode.
N O T E: P ress th e SILEN CE O F F bu tto n can silen ce th e alarm , bu t th e alarm m essage o f th e to u ch
screen do es n o t disappear u n til th e alarm statu s is cleared.
2. Close the UPS external total maintenance bypass switches, and do not close the internal maintenance bypass
switch Q3 of each UPS.
3. At this moment, the external total maintenance bypass should be parallel connected with each UPS's static
bypass.
4. At this moment, the touch screen of each UPS displays ' Maint. Switch Closed'.
5. Disconnect the output switch Q5 of each UPS in turn, and the maintenance bypass can supply power to the
load.
CA UT IO N : Lo ad is n o t secu red o n th e m ain ten an ce bypass an ym o re u n less th ere is po wer
gen erato r ru n n in g in stead o f n o rm al grid u tility.
6. Pressing the EPO button of each UPS stops the operation of rectifier, inverter, static switch and battery, but this
action will not affect the maintenance bypass power the load normally.
N O T E: In m ain ten an ce m o de, th e lo ad is directly fed by th e m ain s po wer in stead o f th e pu re A C po wer
fro m th e in verter.
7. Disconnect the rectifier input switch Q1 and bypass input switch Q2 of each UPS in turn.
At the moment, all the internal power supply is off and the touch screen does not display any more.
W A R N IN G !
1. If th e m ain ten an ce is requ ired, wait 10 m in u tes fo r th e in tern al DC bu s capacitan ce
disch argin g.
2. T h e parts o f UP S circu its also h ave h azardo u s vo ltage, th o u gh th e rectifier in pu t switch ,
bypass in pu t switch an d battery switch are disco n n ected. T h erefo re, th e UP S m ain ten an ce is
applicable to qu alified perso n n el o n ly.
8 Parallel System and LBS System
139
Vertiv™ Liebert® APM Plus User Manual