Dehn PM 20 Bedienungsanleitung Seite 42

Before removing the touch protection, the PM 20 tester has to be switched off in order to prevent the Test
button from being pressed unintentionally.
In principle, the devices to be tested should be tested by means of our test adapters (e.g. PA DRL or PA BXT).
Any surge protective device to be tested is to be removed from the system and has to be
de-energised, even if it is tested without test adapter.
The PM 20 tester may not be used for charging capacitors.
After switching on the device,
PM20 v1 the version of the device is briefly displayed on the LCD,
V before the readiness indicator appears.
Testing is started by briefly pressing the Test button, which clears the LCD V . As a result, the test
voltage rises with 1000V/s and is permanently displayed xxxxV on the LCD. If the Test button is pressed
once again, testing is cancelled brk xxxV .
If the Test button is not pressed again, the test current monitoring system records the response of the device
under test, switches off the test voltage and stores the response value and type of response in the LCD:
VR 400 V Defines the measurement result "400V" as the 1mA reference value of a varistor,
Zener diode, Transzorb diode, etc. or at a resistor.
GA 230 V Indicates that the measured value "230V" is the sparkover voltage of a gas discharge tube or
a spark gap, etc.
> 1100 V Indicates that the measuring range was exceeded due to a higher sparkover voltage of the
device under test or due to an interruption of the test circuit.
In order to evaluate a measurement result, it has to be compared with the relevant reference lists in these
instructions or with the manufacturer's specifications. In this context, the type of response (VR or GA) is
irrelevant.
Attention! Keeping the Test button pressed extends the test period, i.e. as long as the Test button is
pressed, the test voltage remains switched on and is displayed permanently on the LCD.
If a varistor, Zener diode, etc. or resistor is used, the test current is kept constant at 1 mA after the device
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under test has responded.
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