METREL EurotestXE User Manual

MI 3102(H) BT EurotestXE Measurements
44
Connections for testing RCD
Figure 5.20: Connecting the plug commander and the 3-wire test lead
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
N
to avoid trip-out of the RCD
and then normalized to the rated I
∆N
.
Contact voltage measurement procedure
 Select the RCD function using the function selector keys.
 Set sub-function to Uc using UP / DOWN keys.
 Set test parameters (if necessary).
 Connect test cable to the instrument.
 Connect test leads to the item to be tested (see Figure 5.20).
 Press the TEST key to perform the measurement.
 Store the result by pressing the MEM key (optional).
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.
RCD type
Contact voltage Uc
proportional to
Rated I
N
Notes
AC,
EV, MI (a.c. part)
1.05I
N
any
All models
AC
21.05I
N
A, F
1.41.05I
N
 30 mA
A, F
21.41.05I
N
A, F
21.05I
N
< 30 mA
A, F
221.05I
N
B, B+
21.05I
N
any
Model MI 3102 BT
only
B, B+
221.05I
N
Table 5.1: Relationship between Uc and I
 N

METREL EurotestXE Specifications

General

Brand	METREL
Model	EurotestXE
Category	Measuring Instruments
Language	English