80 Chapter 8 Option
NX UPS Single Module And Parallel System 250kVA ~ 800kVA User Manual
Note
This procedure will cause power interruption to the load.
(1) Turn off the load.
(2) Disconnect the mains input and battery from the UPS.
(3) Open the switch upstream of the UPS bypass input.
(4) Wait five minutes for the internal DC bus capacitors to discharge, until all indicators on the UPS display panel turn off.
2) Remove the two rear panels of the bypass cabinet, disconnect the cables W54, W55 and W56 in the bypass
cabinet from the copper bars Q5-2, Q5-4 and Q5-6 of the output switch Q5, and retain the screws.
3) Install the bypass load sharing inductors L1, L2 and L3 in the rear of the bypass cabinet, as shown in Figure 8-2.
The screws for fixing the bottom of the bypass load sharing inductors are provided in the cabinet.
L1
L2
L3
W57
W58
W59
Q5-2
Q5-4
Q5-6
W54
W55
W56
Figure 8-2 Installing bypass load sharing inductors of 600kVA ~ 800kVA UPS (rear view)
4) Connect the cables W57, W58 and W59 according to the cable labels.
Connect the L1, L2 and L3 ends of the cables W57, W58 and W59 respectively to the lower terminals of the bypass
load sharing inductors L1, L2 and L3; connect the Q5-2, Q5-4 and Q5-6 ends of the cables W57, W58 and W59
respectively to the copper bars Q5-2, Q5-4 and Q5-6 of the output switch Q5.
5) Connect the cables W54, W55 and W56 respectively to the upper terminals of the bypass load sharing inductors
L1, L2 and L3.
6) Replace the rear panels of the bypass cabinet.
Note
Make sure that there are no irrelevant objects in the bypass cabinet before replacing the rear panels.
