Liebert 1000kVA Operation & Maintenance Manual page 92

Step 2. If the bypass line is not supplied to the SCC, the LCD screen will be blank. Energize the
bypass line by operating the following controls:
a. Close the Bypass Input Breaker (BIB). This breaker may be in your Maintenance Bypass
cabinet.
NOTE
Wait two minutes after applying bypass power before you operate any other UPS controls.
CAUTION
!
DO NOT assume that the UPS System Bypass Breaker (SBB) is closed.
Instructions for operating the Maintenance Bypass circuit breakers are on the Maintenance
Bypass cabinet.
Make sure you understand the proper sequence before operating any circuit breaker.
Operating a Maintenance Bypass circuit breaker out of sequence could cut off power to the
critical load.
Operations involving MIB and MBB MUST only be done when the UPS system is on internal
bypass.
b. Ensure the SCC Control Power Disconnect is ON. Open the door to the SCC control section
and locate the fuseblock F7 through F10 (see Figure 9). If they are not connected already,
push the fuseholders in to turn ON control power, then reclose the SCC control door.
c. Observe the Monitor/Mimic Display screen to determine if your System Bypass circuit
breaker (SBB) is closed and whether the UPS Bypass line is supplying power to the critical
load.
If your System Bypass circuit breaker is open (as in recovering from an Emergency Power Off
or Low Battery Shutdown), close this circuit breaker as follows:
1. Open the SCC control panel door and find the Transfer Relay Board (Figure 11). If the
red LED (CR18) labeled TOT S/D (Total Shutdown) is on, press the Bypass Reset switch
(SW1) on this board. The red LED should turn off.
2. Set the Static Switch Disconnects (Figure 9) OFF (open), if not off already.
NOTE
Depending on SCC model, the static switch disconnects can be one or two circuit breakers or
two contactors. The location could be at the front, right or rear of the cabinet. Refer to the
drawing of the SCC cabinet selected for your UPS system.
3. Find the Close Bypass switch (SW1) on the System Interface Board (Figure 11, Item 3).
Press this switch to reset the System Bypass circuit breaker. Check the Monitor/Mimic
screen to verify the breaker is closed.
d. If currently OFF, close the Static Switch Disconnects.
NOTE
Depending on SCC model, the static switch disconnects can be one or two circuit breakers
or two contactors. The location could be at the front, right or rear of the cabinet. Refer to the
drawing of the SCC cabinet selected for your UPS system.
4. Press two Reset Switches for Static Switch Disconnects behind door below SCC
control panel (see Figure 9). Note that in an SCCT less than 1600A, there is no Reset
Switch for the Static Switch Disconnect, so this step is not necessary.
5. Set the Static Switch Disconnects to ON (closed).
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Operation