UPS systems even without their batteries are heavy and sometimes bulky items to transport. The logistics side of a UPS installations should be covered during a UPS site survey and run from any permits required outside the building, along the delivery route to the. Smaller single-phase UPS may use 'plug and play' connections meaning that they can be easily installed by a local user or technician. Hardwired UPSand those requiring additional electrical works (e.g. cabling, circuit breakers and distribution panels) require. The critical power path within a UPS installation runs from the loads connected to the power distribution units (PDUs) to the UPS that power the PDUs and to the UPSelectrical. Within some server rooms and datacentre environments it is easy to miss connecting a critical piece of the IT network to a UPS system. Only during a power outage is the omission identified.