Manual

Table Of Contents
46 Gossen Metrawatt GmbH
12.2 Special Tests for Systems and RCDs
12.2.1 Testing Systems and RCCBs with Rising Residual Current
(AC) for Type AC, A/F, B/B+ and EV/MI RCDs
(PROFITEST MTECH+, PROFITEST MXTRA only)
Measuring Method
The instrument generates a continuously rising residual current of
(0.3 … 1.3) × I
N
within the system for the testing of RCDs.
The instrument stores the touch voltage and tripping current val-
ues which were measured at the moment tripping of the RCCB
occurred, and displays them.
One of the touch voltage limit values, U
L
=25V or U
L
=50/65V,
can be selected for measurement with rising residual current.
Select Measuring Function
Connection
Set Parameters for I
F
Start Measurement
Measuring Procedure
After the measuring sequence has been started, the test current
generated by the instrument is continuously increased starting at
0.3 times nominal residual current, until the RCCB is tripped. This
can be observed by viewing gradual filling of the triangle at I.
If touch voltage reaches the selected limit value (U
L
=65V, 50V
or 25 V) before the RCCB is tripped, safety shutdown occurs. The
U
L
/R
L
LED lights up red.
Safety shutdown: At up to 70 V, safety shutdown is trig-
gered within 3 s in accordance with IEC 61010.
If the RCCB is not tripped before rising current reaches nominal
residual current I
N
, the RCD/FI LED lights up red.
If bias current is present within the system during mea-
surement, it’s superimposed onto the residual current
which is generated by the instrument and influences
measured values for touch voltage and tripping current.
See also section 12.1.
Evaluation
According to IEC 60364-6, rising residual current must, however,
be used for measurements in the evaluation of RCDs, and touch
voltage at nominal residual current I
N
must be calculated from
the measured values.
The faster, more simple measuring method should thus be taken
advantage of (see section 12.1).
I
F
Nom. res. current: 10 … 500 mA
Type 1: RCD, SRCD, PRCD …
Nominal current: 6 … 125 A
Type 2*: AC , A , F
, B , B+
, EV, MI
k
* Types B, B+, EV, MI =
AC/DC sensitive
Sinusoidal
Negative/positive half-wave
Waveform:
Connection:
Without/with probe
System type:
TN/TT, IT
Negative/positive direct current
Touch voltage:
Tripping limit values: