ADInstruments AD2811 Manual page 12

V =Voltage of the generator (supply transformer) (internal impedance of transformer = X-Form)
G
Z =Impedance of the Line wire from the transformer, up to the test point (Z
L
this impedance is too high, check the connections of the Line wiring, check the quality of the line wiring and the
switches / contacts in the line circuit.
Z =Impedance of the Neutral wire from the transformer, up to the
N
test point. If this impedance is too high, check the connections of the Neutral wiring, check the quality of the line wiring
and the switches or contacts in the Neutral circuit.
Z =Impedance of the Earth wire, including the Earth Impedance itself, as seen by the protection system. Similar checking,
E
specially at the bounding points should be done is this path impedance is too high.
7. Functions
The tester Measures:
● Line – Earth Voltage
● Line – Earth Loop Impedance.
● Prospective Short Circuit Current L– E.
(This is the current which will flows between Line and Earth,
should a short circuit be made between Line and Earth)
● Line – Neutral Voltage
● Line – Neutral Impedance
● Prospective Short Circuit Current L – N.
(This is the current which will flows between Line and Neutral,
should a short circuit be made between Line and Neutral)
● Earth Spike Impedance (Earth Wire)
● Line + Transformer Impedance (X-Form)
● Neutral Wire Impedance
● Wiring Integrity
The tester report:
● Low battery indication
● Bad wiring
● No line
● Over-Temperature
8. Preparation for measurement
Before testing Always check the following.
● System Voltage
Your Digital Psc / Loop / Earth Tester is best intended to work with 230 Vac. However, if the voltage is lower than that,
the test could still be done but accuracy of the PSC could deteriorate due to the fact that the current injected is lower
than optimal. However, your tester can work on a wide range of voltage and compute results so that those changes
have a minimal effect on Results.
● ELCB / RCCB / GFCI
It is necessary to bypass the ELCB / RCCB / GFCI for the duration of the Earth / Loop / Psc test. Use Leads of same
size as ELCB circuit.
displayed by Instrument also include X-Form). If
L
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