Testing Rcds; Measuring Contact Voltage (In Relation To Nominal Residual Current) With Nominal Residual Current - Gossen MetraWatt ProFiTEST C-GB int. Operating Instructions Manual

6

Testing RCDs

Testing RCDs includes visual inspection, testing and measurement.
®
Use the PROFiTEST C for testing and measurement.
Measuring Method
According to DIN VDE 0100 it must be substantiated that:
– Contact voltage which occurs at nominal residual current does not
exceed the maximum allowable value for the system.
– The RCCBs are tripped within 400 ms at nominal residual current
(1000 ms for selective RCCBs).
Measurement is performed by the instrument with a current having a value
1
of less than / nominal residual current in order to determine contact
3
voltage U at nominal residual current. This prevents the RCCB from
IN
being tripped.
This measuring method offers the special advantage of being able to test
contact voltage at any electrical outlet quickly and easily without tripping
the RCCB.
The usual, cumbersome measuring methods for testing the effectiveness
of RCDs at one measuring point, and having to substantiate that all of the
other system components which require protection are reliably connected
to this measuring point via the PE conductor at low resistance values are
a thing of the past.
Connection
RCD
R
R
E
F
20
6.1
➭
➭
➭
➭
Contact voltage U
calculated earthing resistance R
L1
L2
L3
N
PE
Measuring Contact Voltage (in relation to nominal residual current)
1
with / Nominal Residual Current
3
Select contact voltage measurement with the U
Set nominal residual current for the utilized RCCB with the IN key.
If the contact voltage limit value deviates from 50 V, or if a selective
RCCB is involved, the corresponding value must first be selected by
activating the TYPE key.
Start the measurement by briefly acknowledging with the START key.
I (in relation to nominal residual current) and
IN
are displayed at the LCD.
E
Note
Interference voltages at the protective conductor PE or at the
earth electrode have no influence on measuring results, as long as
they are less than 25 V. Interference voltages can be measured by
performing a voltage measurement with the test plug.
If biasing current with relatively large values is present within the
system, or if the selected test current was too large for the RCCB,
tripping may occur during testing.
In such cases, the following message appears at the display
"Stop! No current. Check breaker".
START
/t key.
IN T
GMC-I Messtechnik GmbH