MD 1050-LED
6.4 Testing AC voltage
When the probe tips are connected to an AC voltage within the nominal voltage range,
the reading is displayed in volts and the “+~-” LED indicator lights up. When the lower
LED-s light up simultaneously, they indicate AC voltage.
A signal tone is emitted when exceeding the threshold value of 35 V. This tone signals
that a dangerous, life-threatening voltage is present.
6.5 Phase testing:
Bring one of the probe tips into contact with a conductor, while touching the finger
contact located at he back. When phase of min. 100V~ is connected, the “<L” LED
lights on.
When using finger contact to determine the phase wire, the perceptibility of the display
con be effected by several factors, including insulated mechanisms that protect against
direct touch, poor positioning (for example, on wooden ladders or on insulated floor
surfaces), an unearthed voltage, or unfavourable lighting conditions.
6.6 Rotary field testing (400V):
Determine which wires are the phase conductors, as described in the “Phase testing”
section. Then place two phase conductors on the test leads an touch the finger contact.
“<L” appears on the display to indicate a counter-clockwise field or “R>” for a clockwise
field. The voltage indicator should give a reading of approx. 400 V. If “<L” appears on
the LCD and only approx. 230 V is displayed, the only one phase conductor is active.
6.7 Continuity and diode testing:
(Hold the test tips together in order to switch on.)
Bring the probe tips into contact with the conductor, fuse, etc. being tested. With
resistances of 0-500k
Ώ
or a semiconductor diode in the conducting direction (the +
probe tip is applied to the anode!) the "Rx/
" LED lights up and an acoustic signal
sounds.
6.8 FI/RCD trigger test, PE (PE conductor test):
The METREL MD 1050 LED carries a load that enables it to trigger a FI/RCD circuit
breaker by means of two buttons (FI/RCD). The FI/RCD (max. 30mA) is tested between
the phase and the PE conductor (max 240 V).
6.9 Battery replacement:
To replace the batteries, ensure that the test probes are not connected to any voltage
source. Turn the battery compartment cap by 90° anti-clockwise and pull away from the
instrument (step 1). Replace the batteries, ensuring that the positive side of the battery
is inserted first (step 2). Replace the cap ensuring that the wider side of the cap is
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