46 GMC-I Messtechnik GmbH
8.10 Measuring Time to Trip for RCDs of the Type PRCD – tA
Schematic Diagram
Wiring Diagram
Definition
According to DIN VDE 0100, part 610:2004, substantiation must
be provided that RCCBs are tripped at nominal residual current
within 400 ms (1000 ms for selective RCCBs).
PRCD Portable residual current device (only those whose
protective conductor is not deactivated)
Applications
The PRCD under test is plugged into the test socket at the test
instrument. The PRCD’s phase conductor must be contacted
with test probe P1 in order to trip the PRCD.
Measurement of time to trip is not possible in IT systems.
Test Sequence
➭ Set the rotary switch to the t
A
position.
➭ Plug the PRCD into the test socket at the test instrument and
connect the test probe to P1.
➭ Start the test: press the START/STOP key.
➭ Acknowledge the warning which indicates that line
voltage will be connected to the test socket.
Execute the following steps when prompted to do so:
Please note that test probe P1 is in continuous contact
with the phase conductor from the point in time at which
the PRCD is plugged in until it trips. Premature discon-
nection of the test probe may result in erroneous mea-
sured values.
➭ After each reconnection to the mains, and as soon as the first
test is started, a mains connection test is executed.
➭ If the probe test has revealed that probe P1 was not con-
nected: connect probe P1 as described above.
➭ Switch the PRCD on after connectiong to line voltage (e.g.
reset button on PRCD).
➭ Contact neutral conductor L at the PRCD with test probe P1
(ascertain by trial and error if necessary).
➭ The test is automatically ended and time to trip is displayed
after the PRCD is tripped.
➭ The save symbol appears and prompts you to save the
measured values to an ID number.
➭ Press the ESC key in order to discard the measured
values stored to buffer memory and acknowledge by
pressing the key shown at the right.
Single measurements, rotary switch level: green
Switch
Position
Measuring Functions Measurement
Type,
With Mains
to Test Socket
t
A
ta
PRCD time to trip for 30 mA PRCD
U
LN
Line voltage at the test socket