18 GMC-I Messtechnik GmbH
7.2.3 Testing RCCBS with 5 I
N
The measurement of time to trip is performed here with 5 times
nominal residual current.
Measurement performed with 5 times nominal residual
current is required for testing RCCBs and G 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 Parameters – Positive or Negative Half-Wave
Set Parameters – 5 Times Nominal Current
The following limitations apply when selecting X times
tripping current relative to nominal current:
300 mA: 1 x I
N
, 2 x I
N
500 mA: 1 x I
N
Start Measurement
7.2.4 Testing RCCBs which are Suited for
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 Parameters – Positive or Negative Half-Wave
Set Parameters – Testing with and without Biasing Current
Non-Trip Test (Testing with Biasing Current):
If RCD is tripped to early during the non-trip test
with 50 % I
N
for 2 seconds , i. e. prior to actual
tripping, the popup window shown at the right
appears.
The following limitations apply when selecting X times
tripping current relative to nominal current:
300 mA: 1 x I
N
, 2 x I
N
500 mA: 1 x I
N
According to DIN EN 50178 (VDE 160), only type B
RCCBs (AC-DC sensitive) can be used for equipment
with greater than 4 kVA which is capable of generating
smooth DC residual current (e.g. frequency converters).
Tests with pulsating DC residual current are not suitable
for these RCCBs.
Measurement is performed with positive and negative
half-waves when testing RCCBs during manufacturing. If
a circuit is charged with pulsating direct current, the
function of the RCCB can be executed with this test in
order to assure that the RCCB is not saturated by the pul-
sating direct current such that it no longer trips.
Negative half-wave
Positive half-wave
Waveform:
Negative direct current
Positive direct current
X times tripping current:
5 times tripping current
Negative half-wave
Positive half-wave
Waveform:
Negative direct current
Positive direct current
X times tripping current:
Biasing current 50% I
N
To Next Page
Loading...
Need help?
General
