in line interactive UPS, the inverter provides what two functions?
- rectifier provides power to batteries to maintain their charge (power)
- Filters main power going to the communications equipment (filtering)
The three main parts of emergency power systems are
- batteries
- rectifier
- inverter
batteries
- provides dc energy + needs dc to recharge batteries
- one or more cells for chemical reaction that creates electricity
- lead acid batteries most common
rectifier
- converts Alternating Current (AC) to DC
- needed to supply DC power to recharge batteries
- also used as power filters to protect sensitive equipment from power spikes, power sags, and other issues
inverter
- an electrical component that converts DC to AC
- used when power source,( ie: battery), provides DC power
- most power distribution system + com equipment are designed to use AC
Uninterruptible power supply (UPS)
an electrical power device with a battery (or batteries), rectifier, and inverter
The three main purposes of an UPS are to:
- Provide short-term temporary power to a computing device in the event of main power failure
- Initiate the graceful shutdown of servers and PCs (Optional)
- Provide protection from power surges/spikes
If an abnormality is detected, such as a surge or sag in voltage or current, the UPS __________, or “cleans”, the power so that communications equipment can continue to function.
filters
In the event of complete main power failure, the UPS can temporarily provide
power from its batteries until main power is restored or generators can come online.
In the event main power is not restored before the UPS’s batteries are depleted and a generator is not available, some UPSs can direct servers and other communications equipment to
start their graceful shutdown process so that equipment damage and data corruption are prevented.
three common types of UPSs
standby, line interactive, and double conversion (sometimes called online)
standby UPS
- passes main power through to the communications equipment
- only switches to its batteries and inverter in the event of main power variations or failure
- most used for PCs
line interactive UPS
- main power is still the primary power source
- inverter is always on
- involved with power delivery to the communications equipment
line interactive UPS is most commonly used for
servers
double conversion UPS
- rectifier is connected to the main power feed, and the AC is converted to DC
- inverter converts DC back to AC for delivery to power outlets.
- converts the power twice during normal operation
- very clean and reliable power to comms. equip.
double conversion UPS is most commonly used for
multiple racks or entire rooms of communication equipment
facility battery backup power
operate similarly to double conversion UPSs but the batteries are ALWAYS in use
The main purpose most of the communication facility battery backups is to
provide** medium-term** power to critical communications equipment
(main analog phone switch and support equipment, such as operator terminals).
Many factors impact the amount of time the facility battery backup system can provide power, including:
- the ampere hour rating of the batteries
- condition of the batteries
- charge level of the batteries
- amount of power consumed by the communications equipment.
For most COs and other communications facilities without standby generators, the batteries ________ ______________ to provide power for approximately eight hours
are required
For COs and other communications facilities with a standby generator, the batteries should provide power for
3-5 hours
generators designed to provide
medium- to long-term power to a communications facility in the event of an extended main power outage
generator converts
mechanical energy to electrical energy
The reason the UPSs and facility battery backups are included in the power consumption calculation is because
the generator needs to provide sufficient power to recharge the batteries of these systems, along with running the other equipment and systems of the facility
