Page 114 - CITS - Electronic Mechanic - TT - 2024
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ELECTRONICS MECHANIC - CITS




                               Symptom                                         Specification

            Rating                                           600 VA
            Input Voltage                                    150V AC to 275 V AC
            Output Voltage                                   220V AC- Nominal

            Protection (input fuse)                           Provided
            DC Input                                         12 V
            Battery Type                                     Sealed lead-acid
            Battery recharge time                            8 hours (up to 90%of full capacity)
            Battery Capacity                                 12V 7AH

           Power Range of UPS:
           UPS are made in following three power ranges.

           Low Power Range – up to 1000 VA
           Medium Power Range – up to 10 KVA
           High Power Range – above 10 KVA
           Selection Of UPS:
           When selecting an uninterruptible power system, engineers must consider the following factors that can make or
           break the success of the system.
           Load Size: The Size of the critical load determine the capacity of the initial installation. The UPS must have
           adequate capacity to reliably serve the critical load and additional loads, without immediate expansion.
           Input Voltage: The input voltage available at the site and fluctuations occur generally.
           Output Power Range: The total wattage of the load to be connected to the UPS.
           Battery Run Time: The battery run time of a UPS is the length of time the UPS can reliably supply power to the
           critical load after input power has failed. Run time usually is defined as the length of time required for connecting
           data-processing equipment to save data files and shut down in an orderly fashion, along with a margin of safety.
           Typically, Battery run time is 15 min. Hence, someone must review the proposed installation to determine if
           modification is necessary to support the load.
           Changeover Period: Changeover period should be less than 1 us for computers.
           Indicator Used:
           1  Power on Indicator: This LED indicates whether the UPS unit is powered on and receiving electricity from an
              external power source.
           2  Battery Status Indicator: This LED provides information on the charge level of the UPS’s internal battery. It
              helps users determine whether the battery is fully charged or if it needs to be recharged.

           3  Load Capacity Indicator: The load capacity indicator helps users gauge the amount of power being drawn
              from the UPS. It indicates whether the load is within acceptable limits or if it is approaching or exceeding the
              UPS’s capacity.
           4  Fault or Alarm Indicator: This LED is crucial for identifying any faults or alarms that the UPS has encountered.
              It can signal issues such as overload, battery failure, or any other problems that require immediate attention.
           Protection Required:
           UPS components include a rectifier, ups battery, an inverter and a static switch. Within a modern system these are
           usually set up in an online configuration. This means that during normal operation the incoming mains feeds the
           rectifier which in turn supplies the inverter with a stable DC voltage as well as float-charging the battery.
           If the mains supply transgresses acceptable limits, power to the inverter is provided by the battery until either
           normal main is restored or the battery is exhausted. As the battery nears exhaustion, the static switch can be used
           to transfer the load to a bypass supply.



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                                    CITS : E & H - Electronics Mechanic - Lesson 56 - 63
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