KYORITSU 4116A - Measurement of OLD-TT System

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MaxvalueofZsforthisexampleis2.1Ω (16AgGfuse,0.4s)thelooptester
reads1.14Ω (or202AonFaultcurrentrange)itmeansthatthecondition
Zs
＜
Uo/Ia
isrespected.
InfacttheZsof1.14Ω islessthan2.1Ω (ortheFaultcurrentof 202Ais
morethanIaof110A).
6.2Measurementof"OLD-TTSystem"
OLD-TTsystemisa TTsystemwith phasetophasevoltage of220V
(insteadof400V) andphasetoearth of127V(instead of230V)and
normallytheneutralconductorisnotused.
Connectingthe looptesters tothis system,all threewiring checkLEDs
shouldbelitandthedisplayreadsavalueof127V.
Onlyif
all
theseconditionsarerespectedthetestcanbecarryout.
Fig.10
WARNING
● Thisinstrumentisintendedonlyforuseinsinglephaseoperation
at230V+10% -15%AC phasetoearth orfor useinOLD-TT
systemphasetoneutral.
● Iftheoverheatsymbolappearsinthedisplay( )disconnectthe
instrumentfromthemainssupplyandallowtocooldown.
L1
L2
L3
PE
R
R
O
RCD 30mA
220V
220V
220V