User guide

15
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