User Manual

GMC-I Messtechnik GmbH 21
7.2.3 Testing RCCBS with 5 • I
∆N
Measurement of time to trip is performed here with 5 times nomi-
nal residual current.
Note
Measurements performed with 5 times nominal fault cur-
rent are required for testing type and G RCCBs in the
manufacturing process. They are used for personal
safety as well.
Measurement can be started with the positive half-wave at “0°” or
with the negative half-wave at “180°”.
Both measurements must nevertheless be performed. The longer
of the two tripping times is decisive regarding the condition of the
tested RCCB. Both values must be less than 40 ms.
Select the Measuring Function
Set the Parameter – Start with Positive or Negative Half-Wave
Set the Parameter – 5 Times Nominal Current
Note
The following restrictions apply to the selection of tripping
current multiples relative to nominal current:
500 mA: 1 x, 2 x I
∆N
Start Measurement
7.2.4 Testing of RCCBs
Pulsating DC Residual Current
In this case, RCCBs can be tested with either positive or negative
half-waves. The standard calls for tripping at 1.4 times nominal
current.
Select the Measuring Function
Set the Parameter – Positive or Negative Half-Wave
Set the Parameter – Test With and Without “No-Trip Test”
No-Trip Test
If, during the no-trip test which lasts for 1 sec-
ond, the RCD trips too early at 50% I
∆N
, i.e.
before the actual tripping test starts, the pop-up
window shown at the right appears.
Note
The following restriction applies to the selection of tripping
current multiples relative to nominal current:
double and
five-fold nominal current is not possible in this case.
Note
According to DIN EN 50178 (VDE 160), only type B
RCCBs (AC-DC sensitive) can be used for equipment
with > 4 kVA, which is capable of generating smooth DC
residual current (e.g. frequency converters).
Tests with pulsating DC fault current only are not suitable
for these RCCBs. Testing must also be conducted with
smooth DC residual current in this case.
Note
Measurement is performed with positive and negative
half-waves for testing RCCBs during manufacturing. If a
circuit is charged with pulsating direct current, the func-
tion of the RCCB can be executed with this test in order
to assure that the RCCB is not saturated by the pulsating
direct current so that it no longer trips.
S
I
∆N
Positive direct current
Waveform:
180°: Start with negative half-wave
0°: Start with positive half-wave
5 times tripping current
X times tripping current
I
∆N
Negative half-wave
Positive half-wave
Positive direct current
Waveform:
X times tripping current
50% I
∆N
*
* No-trip test with 50% I
∆N