METREL MI 3125 User Manual

MI 3125 EurotestCOMBO Testing RCD
33
Connections for testing RCD
L1
L2
L3
N
PE
R E
Ro
LPEN
L
/
L
1
N
/
L
2
P
E
/
L
3
Figure 5.18: Connecting the plug commander and the universal test cable
5.5.1 Contact voltage (RCD Uc)
A current flowing into the PE terminal causes a voltage drop on earth resistance, i.e.
voltage difference between PE equipotential bonding circuit and earth. This voltage
difference is called contact voltage and is present on all accessible conductive parts
connected to the PE. It shall always be lower than the conventional safety limit voltage.
The contact voltage is measured with a test current lower than ½ I
ΔN
to avoid trip-out of
the RCD and then normalized to the rated I
ΔN
.
Contact voltage measurement procedure
 Select the RCD function using the function selector switch.
 Set sub-function Uc.
 Set test parameters (if necessary).
 Connect test cable to the instrument.
 Connect test leads to the item to be tested (see figure 5.18).
 Press the TEST key to perform the measurement.
The contact voltage result relates to the rated nominal residual current of the RCD and
is multiplied by an appropriate factor (depending on RCD type and type of test current).
The 1.05 factor is applied to avoid negative tolerance of result. See table 5.1 for detailed
contact voltage calculation factors.

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)