User Manual
GMC-I Messtechnik GmbH 21
7.2 Special Testing for Systems and RCCBs
7.2.1 Testing Systems and RCCBs with Rising Residual Current 
(AC) for Type AC, A/F, B/B+ and EV/MI RCDs
Measuring Method
The instrument generates a continuously rising residual current of 
(0.3 to 1.3) • I
ΔN
 within the system for the testing of RCDs.
The instrument stores the contact voltage and tripping current 
values which were measured at the moment tripping of the RCCB 
occurred, and displays them.
One of contact voltage limit values, U
L
=25V or U
L
=50V/65V, 
can be selected for measurement with rising residual current.
Select Measuring Function
Connection 
Set Parameters for I
F
Start Measurement 
Measuring Sequence
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 IΔ. 
If contact voltage reaches the selected limit value (U
L
=65V, 50V 
or 25 V) before the RCCB is tripped, safety shut-down occurs. 
The U
L
/R
L
 LED lights up red. 
Note
Safety Shut-down: At up to 70 V, a safety shut-down is 
tripped within 3 seconds in accordance with IEC 61010.
If the RCCB is not tripped before the rising current reaches nomi-
nal residual current I
ΔN
, the RCD/FI LED lights up red.
Attention!
!
If bias current is present within the system during mea-
surement, it is superimposed onto the residual current 
which is generated by the instrument and influences 
measured values for contact voltage and tripping cur-
rent. See also section 7.1.
Evaluation
According to DIN VDE 0100, Part 600, rising residual current 
must, however, be used for measurements in the evaluation of 
RCDs, and contact voltage at nominal residual current I
ΔN
 must 
be calculated from the measured values.
The faster, more simple measuring method should thus be taken 
advantage of (see sectionl 7.1).
7.2.2 Testing Systems and RCCBs with Rising Residual Current 
(AC) for Type B/B+ and EV/MI RCDs (only MTECH+, MXTRA 
& SECULIFE IP)
In accordance with VDE 0413, part 6, it must be substantiated 
that, with smooth direct current, residual operating current is no 
more than twice the value of rated residual current I
ΔN
. A continu-
ously rising direct current, beginning with 0.2 times rated residual 
current I
ΔN
, must be applied to this end. If current rise is linear, ris-
ing current may not exceed twice the value of I
ΔN
 within a period 
of 5 seconds.
Testing with smoothed direct current must be possible in both 
test current directions.
I
F
Nominal residual current: 
Type 1: RCD, SRCD, PRCD etc.
Nominal current: 6 ... 125 A
Type 2: AC  , A/F  , B/B+   *
EV/MI
* Type B/B+/EV/MI = AC/DC sensitive
10 ... 500 mA
sine
Negative/positive half-wave
Waveform:
Connection:
without/with probe
System type:
TN/TT, IT
Negative/positive direct current
Contact voltage:
Tripping limit values:










