MI 3102(H) BT
Eurotest
XE
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
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
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
