Operation 97
3.3.2 Load TransferProcedures
Usethe Monitor/Mimic Display at the SCC to determine the operatingcondition of the UPS system. Press the
AlarmReset pad t o clear the Alarm Messages. R efer to Tabl e 1 for an explanationof any remaining alarm mes-
sages(except Load On Bypass). Call Liebert Global Services if you cannot clearthe remaining alarm messages.
Ifthe only alarm message displayed is Load On Bypass (orno alarms), you can perform a manual transfer of the
loadbetween the UPS system and the UPS bypass line. Changing the load from the UPS system to the UPS
bypass is called a transfer. Changing the loadfrom UPS bypass to the UPS system is called a retransfer.Note
thatthe UPS system control logic can initiate automaticload transfers and retransfers. Refer to 3.4 - Automatic
Operations.
Pressthe Sel ect padto display the Master Menu on the LCD display of theSCC. Move the highlighted cursor to
LoadTransfer Procedures (using the Up and Down pads). Press the Select pad to display the Load TransferPro-
cedures screen.
Step 1. Verify that the OK TO TRANSFER message is highlighted. If not (if the TRANSFER PROHIBIT
messageis highlighted instead), slowly rotatethe Voltage Adjust knob (Figu re 10, item 6) to matchthe UPS
systemvoltage to the bypass voltage.
Figure 61 Load Transfer Procedures Screen
Step 2. Perform Step 2 on the Load Transfer Procedures Screen.
a. Ift hel oad iso n theU PS system, simultaneouslypress the Bypass and Control Enable pa ds
(Figure 10). This will close the motorized System Bypass circuit breaker (SBB) and open the
motorizedUPS Output circuit breaker in a make-before-break sequence.
b. Ifthe load is on the UPS bypass, simultaneously press the UPS and Control Enable pads (Figure 10).
Thiswill close the motorized UPS Output circuitbreaker and open the motorized System Bypass circuit
breaker(SBB) in a make-before-breaksequence.
Returnto the Monitor/Mimic Display screen to monitorthe operation of the UPS system. Press the Alarm Reset
padto clear any latched alarm messages removed by the new load status. Refer to Tabl e 1 if an alarm message
otherthan Load On Bypass is still displayed. Contact Liebert Global Servicesif you require assistance.
NOTE
1. UPSoutput voltage changes VERYslowly in response to movements of the
VoltageAdjust knob. Toavoid overshooting, allow at least a minutefor U PS
outputvoltage to stabilize before proceedingto the next step.
2. Ifthe TRANSFER PROHIBIT message remains,refer to Table 1 for corrective
actionfor any alarm messages. Call Liebert Global Servicesif you cannot solve
theproblem.
TRANSFER PROHIBIT
UPS LEAD = 2Deg
UPS -
BYPASS -
380380
380381
B-CA-B
VOLTAGECOMPARISON
SELECT : MASTERMENU
OK TO TRANSFER
+30
ONUPS
50.0Hz
379
C-A FREQUENCY
MANUAL
TRANSFERINSTRUCTIONS
1. AdjusttheUPS voltage until it equals the
bypassvoltage with the VOLTAGEADJUST pot.
2. IftheO KTO TRANSFER message is highlighted,
simultaneouslypressthe BYPASS andCONTROL ENABLE
buttons.
3. Verifythatthe transfer was successful by checking the
breakerstatus on the "MONITOR/MIMIC"screen.
4. PresstheALARM RESET button to clear alarms which
areno longer active
SYNCHRONIZATION
50.0Hz
0-30
380
DISCONTINUED
PROD U C T