METREL MI 3125 User Manual

MI 3125 EurotestCOMBO Fault loop impedance
40
Fault loop impedance measurement procedure
 Select the Zloop or Zs rcd subfunction using the function selector switch and
¿/À keys
 Select test parameters (optional).
 Connect test cable to the Instaltest Combo.
 Connect test leads to the item to be tested (see figure 5.25 and 5.18).
 Press the TEST key to perform the measurement.
Figure 5.26: Examples of loop impedance measurement result
Displayed results:
Z..............Fault loop impedance,
ISC............Prospective fault current,
Lim ..........Low limit prospective short-circuit current value or high limit fault loop
impedance value for the UK version.
Prospective fault current I
SC
is calculated from measured impedance as follows:
Z
kUn
I
SC
SC
×
=
where:
Un ........Nominal U
L-PE
voltage (see table below),
ksc ....... Correction factor for Isc (see chapter 4.2.6).
U
n
Input voltage (L-PE)
115 V
(100 V
≤ U
L-PE
< 160 V)
230 V
(160 V
≤ U
L-PE
≤ 264 V)
Notes:
 High fluctuations of mains voltage can influence the measurement results (the
noise sign is displayed in the message field). In this case it is recommended
to repeat few measurements to check if the readings are stable.

This measurement will trip-out the RCD in RCD-protected electrical installation if
test Zloop is selected.
 Select Zs rcd to prevent trip-out of RCD in RCD protected installation.

METREL MI 3125 Specifications

General

Type	Multifunction Installation Tester
Insulation Resistance	Yes
Continuity Test	Yes
Loop Impedance	Yes
RCD Testing	Yes
Voltage Measurement	Yes
Frequency Measurement	Yes
Display	LCD
Power Supply	6 x 1.5 V AA batteries
Loop Resistance Resolution	0.01 Ω
Frequency	45 - 65 Hz
Line Voltage Resolution	1 V
Insulation Resistance Test Voltage	50 V, 100 V, 250 V, 500 V, 1000 V
Insulation Resistance Resolution	0.01 MΩ
Continuity Resistance Resolution	0.01 Ω
Test Current	200 mA
DC Voltage	Up to 600 V
Loop Resistance	0.0 Ω - 1999 Ω
Line Voltage	Up to 550 V
Line Voltage Accuracy	±2% ±2 digits
Rated Residual Current	10 mA, 30 mA, 100 mA, 300 mA, 500 mA
Insulation Resistance Range	0.01 MΩ to 1 TΩ
Continuity Resistance	0.0 Ω - 1999 Ω
Dimensions	220 x 103 x 55 mm
Operating Temperature	-10°C to 50°C
Storage Temperature	-20°C to +60°C
Safety Standards	EN 61557
Loop Resistance Accuracy	±(5% + 3 digits)