Section-44, Routing the mainline power cables, not connecting to the UPS Procedure Locate the mainline power cables boxes in Box 1 of 10. Determine the power source for the mainline power cables or each UPS (E61, E62). Note: It is strongly recommended the customer use two different power sources. If the source power connectors are external to the rack, the mainline power cables are 4.3 meters. If the source power connectors are internal to the rack, the mainline power cables are less than 2 meters. Route, but DO NOT CONNECT the mainline power cables from the power source to the UPS.