Vertiv Liebert APM Plus - Back-Feed Contactor Option

9.2.14 Back-feed Contactor Option
The main back-feed contactor and the bypass back-feed contactor are provided respectively. The contactor is installed
inside the cabinet and is directly supplied by the input power. The contactor is disconnected when the input power is lost.
When the side cabinet is selected, the back door of UPS is installed against the wall, and the right-side door shall be opened
for repair and modification of contactor components. As shown in Figure 9.12 below.
Figure 9.12 W iring of back-feed con tactor
N o. D es cription
1 Main back-feed contactor
2 Bypass back-feed contactor
9 Options
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Vertiv™ Liebert® APM Plus User Manual