User Manual

GMC-I Messtechnik GmbH 61
14.8 Testing Residual Current Monitors
– RCM Function (PROFITEST MXTRA only)
General
Residual current monitors (RCMs) monitor residual current in elec-
trical systems and display it continuously. As is also the case with
residual current devices, external switching devices can be con-
trolled in order to shut down supply power in the event that a
specified residual current value is exceeded.
However, the advan-
tage of an RCM is that
the user is informed of
fault current within the
system before shutdown
takes place.
As opposed to individual
measurement of I
ΔN
and
t
A
, measurement results
must be evaluated man-
ually in this case.
If an RCM is used in
combination with an
external switching
device, the combination
must be tested as if it
were an RCD.
Connection
Set Parameters for I
F
Measure Contact Voltage
Non-Tripping Test with 1/2 x I
Δ N
and 10 s
After 10 seconds have passed, no fault current may be signalled.
The measurement must be evaluated afterwards. In the event that
“NOT OK” is selected (in case of false alarm), an error is indicated
by the UL/RL LED which lights up red.
The measured value cannot be saved to memory and included in
the test report until it has been evaluated.
Tripping Test with 1 x I
ΔN
– Measurement of Signal Response Time (stopwatch function)
with the Residual Current Generated by the Test Instrument
In order to document the tripping time, the measurement must be
stopped manually with the ON/START or I
ΔN
key immediately after
the fault current has been signalled.
In the event that “NOT OK” is selected, an error is indicated by the
UL/RL LED which lights up red.
The measured value cannot be saved to memory and included in
the test report until it has been evaluated.
Nom. res. current: 10 ... 500 mA
Waveform:
Nominal current: 6 ... 125 A
Type: A , B *
* Type B = AC/DC sensitive
X times tripping current:
Connection: without/with probe
System type: TN/TT, IT
Contact voltage:
< 25 V, < 50 V, < 65 V