Samlexpower PST-100S-12E Owner's Manual - Section 2 |
6 | SAMLEX AMERICA INC.
seCtIOn 2 |
General Information
Thefollowingdefinitionsareusedinthismanualforexplainingvariouselectrical
concepts,specificationsandoperations:
Peak Value:Itisthemaximumvalueofelectricalparameterlikevoltage/current.
RMS (Root Mean Square) Value: It is a statistical average value of a quantity that varies
invaluewithrespecttotime.forexample,apuresinewavethatalternatesbetween
peakvaluesofPositive325VandNegative325VhasanRMSvalueof230VAC.Also,for
apuresinewave,theRMSvalue=Peakvalue÷1.414.
Voltage (V), Volts: It is denoted by “V” and the unit is “Volts”. It is the electrical force
thatdriveselectricalcurrent(I)whenconnectedtoaload.ItcanbeDC(DirectCurrent
–flowinonedirectiononly)orAC(AlternatingCurrent–directionofflowchangesperi-
odically).TheACvalueshowninthespecificationsistheRMS(RootMeanSquare)value.
current (i), Amps, A:Itisdenotedby“I”andtheunitisAmperes–shownas“A”.Itis
theflowofelectronsthroughaconductorwhenavoltage(V)isappliedacrossit.
Frequency (F), Hz: It is a measure of the number of occurrences of a repeating event per
unittime.forexample,cyclespersecond(orHertz)inasinusoidalvoltage.
efficiency, (
η
):ThisistheratioofPoweroutput÷PowerInput.
Phase Angle, (
φ): It is denoted by “φ” and specifies the angle in degrees by which the
current vector leads or lags the voltage vector in a sinusoidal voltage. In a purely induc-
tiveload,thecurrentvectorlagsthevoltagevectorbyPhaseAngle(
φ)=90°.Inapurely
capacitiveload,thecurrentvectorleadsthevoltagevectorbyPhaseAngle,(
φ)=90°.In
apurelyresistiveload,thecurrentvectorisinphasewiththevoltagevectorandhence,
thePhaseAngle,(
φ)=0°.Inaloadconsistingofacombinationofresistances,induct-
ancesandcapacitances,thePhaseAngle(
φ)ofthenetcurrentvectorwillbe>0°<90°
and may lag or lead the voltage vector.
Resistance (R), Ω: It is the property of a conductor that opposes the flow of current
whenavoltageisappliedacrossit.Inaresistance,thecurrentisinphasewiththevolt-
age. It is denoted by "r" and its unit is "ohm" - also denoted as "Ω".
inductive Reactance (X
L
), capacitive Reactance (X
c
) and Reactance (X): reactance is the
opposition of a circuit element to a change of electric current or voltage due to that
element's inductance or capacitance. Inductive reactance (X
L
)isthepropertyofacoil
of wire in resisting any change of electric current through the coil. It is proportional to
frequency and inductance and causes the current vector to lag the voltage vector by
PhaseAngle(
φ)=90°.Capacitivereactance(X
c
)isthepropertyofcapacitiveelementsto
oppose changes in voltage. X
c
is inversely proportional to the frequency and capacitance
andcausesthecurrentvectortoleadthevoltagevectorbyPhaseAngle(
φ)=90°.The
unit of both X
L
and X
c
is "ohm" - also denoted as "Ω". The effects of inductive reac-
tance X
L
tocausethecurrenttolagthevoltageby90°andthatofthecapacitive
reactance X
c
tocausethecurrenttoleadthevoltageby90°areexactlyoppositeand