Characterstics of Static Relay Undervoltageovervoltage (1)
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Characteristics of Static Relay Under Voltage/Over Voltage Aim: To study the operation of Microprocessor Based type under voltage relay and hence to obtain inverse time/voltage characteristics. Apparatus required: S.N o Apparatus Type Quantit y Theory: Over Voltage/Under Voltage Relay is an electronic microcontroller based single-phase voltage relay. It is suitable for over voltage/under voltage protection schemes in LV, MV and HV power distribution systems. It is also suitable for over voltage protection of AC circuits, capacitors, machines such as generators, synchronous motor and under voltage protection of AC circuits, Induction motors, automatic change over schemes etc. The microcontroller-based design offers a wide range of Trip-Time characteristics, under voltage or over voltage mode and PT rating (110V, 240V, 415V), which can all be selected in the field at the time of commissioning. It accepts very wide auxiliary supply range. Relay is designed for flush mounting. It is very compact in size, which results in saving of panel space. Its draw-out construction makes installation and maintenance very easy. Details of L&T Under voltage/Over voltage relay:
Characterstics of Static Relay Undervoltageovervoltage (1)
Characteristics of Static Relay Under Voltage/OverVoltageAim: To
study the operation of Microprocessor Based type under voltage
relay and hence toobtain inverse time/voltage
characteristics.Apparatus required:S.oApparatus!ype"uantity !heory:
Over Voltage/Under Voltage Relay is an electronic microcontroller
based single-phase voltage relay. t is suitable for over
voltage/under voltage protection schemes in !V"MV and #V po$er
distribution systems. t is also suitable for over voltage
protection of %&circuits" capacitors" machines suchas
generators" synchronous motor andunder voltageprotection of
%&circuits" nduction motors" automatic change over schemes etc.
Themicrocontroller-based design offers a $ide range of Trip-Time
characteristics" under voltageor over voltage mode and 'T rating
())*V" +,*V" ,)-V." $hich can all be selected in the fieldat the
time of commissioning. t accepts very $ide au/iliary supply range.
Relay is designedfor flush mounting. t is very compact in si0e"
$hich results in saving of panel space. tsdra$-out construction
ma1es installation and maintenance very easy.#etails of $%! Under
voltage/Over voltage relay:2ig )3 Under/Over Voltage
RelayRelayMV)+isasinglephase"overvoltageorundervoltagerelay$ithone
measuringelement. The relay can be used for feeder protection in
alllo$ voltage" medium voltage andhigh voltage sub-stations. 4'
s$itchesare
providedonthefrontpanelforpic1upandtimedelaysettings.Userhasa
choice of 5 trip timecharacteristics. 2ig +3 nter circuit diagram
of the relay Technical 6pecifications of the relay are3).* Rated
Voltage(Vn.))* / +,* / ,)- V %& (2ield 6electable.+.* Rated
2re7uency -*#0 +.- #08.* %u/iliary 'o$er 6upply +,V to ))*V
%&/4&OR9-V to +,*V %&/4&,.* Relay 6ettings3'ic1 up
voltage (Vs.Over Voltage Mode )*-: to );*: of Vn in steps of
-:Under Voltage mode 9-: to +*: of Vn in steps of - :Time
MultiplierTM6 *.) to ).< in steps of *.)-.* Operating
&haracteristicsTime /&urrent characteristics =ormal nverse
8.- sec in O/V mode=ormal nverse -.5 sec in U/V mode 4efinite time
)" )*" )** sec'ic1 up voltage 6ame as set voltage VsReset Voltage
(9*: to 9-: .of set voltage Vs for Over voltage ()*-: to ))*: .of
set voltage Vs for Undervoltage%ccuracy -: Operating time 3=ormal
nverse %s per 68+8)3)9;5. 'lease refer fig. + for
details.(ThecurveisgivenforVn>))*V.2orVn>+,*Vand Vn>,)- V
" it is limited by over load capacity.4efinite time Three ranges ()
sec" )* sec" )** sec.Time > TM6 / Rangec.
?iththreerangesasabove"usercangetadefinite time delay from *.)sec
to )
