GMC-I Messtechnik GmbH
13
4
General Operation
4.1
Connecting the Instrument
Connect the instrument to the mains with the test plug if the system to be
tested is equipped with earthing contact outlets. Voltage between phase L
and protective earth PE may not exceed 253 V!
Poling at the plug can be ignored. The instrument determines the
positions of phase L and neutral N, and automatically reverses poles if
necessary. This does not apply to the following measurements, in order to
allow for conscious determination of poling at the plug:
–
Voltage measurement in switch position U
L-PE
–
Phase sequence measurement
The position of phase L is identified on the plug.
If measurements are take at 3-phase outlets, at distribution cabinets or at
permanent connections, use the 3-phase measuring adapter (see page
2), and attach it to the test plug.
4.1.1 Checking Earthing Contact Outlets for Correct Connection
Checking earthing contact outlets for correct connection prior to protec-
tive measures testing is simplified with the error recognition system
integrated in to the test instrument. The instrument displays faulty
connections as follows:
•
Impermissible line voltage (< 170 V or > 253 V):
The NETZ/MAINS lamp blinks red and the measuring function is
disabled.
•
Protective conductor not connected, or potential to earth
100 V
at > 45 Hz:
When contact is made with the contact surface, the PE lamp lights up
red.
Measurement is not disabled by the illuminated lamp.
•
Neutral conductor N is not connected (2-pole connection):
The NETZ/MAINS lamp blinks green.
See “Lamp Functions” on page 33.
In countries with polarized electrical outlets
(Great Britain, France, Switzer-
land, Czech republic etc.), it is advantageous to be able to recognize at
first glance whether or not L and N have been correctly connected to the
outlet, see table on page 3. To date, it has been necessary to initialize the
U
L
-PE voltage measuring function to this end. As of software version AI,
symbols are already displayed in the test instrument’s start menu which
provide clear-cut information regarding connection of the outlet to the
mains.
Attention!
!
Reversal of N and PE in TN systems cannot be recognized and is
not indicated.
Reversal of N and PE in electrical systems equipped with RCCBs
can be detected by means of loop impedance measurement. The
RCCB is not tripped during measurement.
4.2
Automatic Settings, Monitoring and Shutdown
The PRO
Fi
TEST
®
C makes appropriate settings for all of the operating
conditions it is able to determine on its own. It tests voltage and frequency
at the electrical system.
Line voltage fluctuations have no influence on measurement results.
The contact voltage which is generated by the instrument is monitored
during each measurement. If contact voltage exceeds the 50 V limit value,
the measurement is interrupted immediately. The U
L
amp lights up red.
If battery voltage drops to below 4.6 V, the instrument cannot be switched
on, or it is immediately switched off.
Measurement is interrupted automatically, or the measuring sequence is
disabled (except for voltage measuring ranges and phase sequence
measurement):
•
If impermissible line voltages occur (< 170 V, > 253 V) during
measurements, for which line voltage is required
•
If excessive temperatures prevail within the instrument
Impermissible temperatures usually do not occur until after approxi-
mately 50 measuring sequences have been performed once every
5 seconds when the Z
Loop
function has been selected.
If an attempt is made to start a new measuring sequence, an
appropriate message appears at the LCD.
The instrument switches itself off automatically, at the earliest after the
current (automatic) measuring sequence has been completed, and after
the predefined on-time has elapsed (see chapter 3.4). On-time is reset to
the duration selected in the setup menu each time a key is activated.
