20
GMC-I Messtechnik GmbH
The display can settle in within a range of 0 Ohm (if all cores are short-circuited) up to, for
example, infinity (in the event of overload) if one core is interrupted. Due to good insulation
assured by undamaged cables, a test value of 10 MOhm with a tolerance of 20% has been
established for this rational test procedure.
All values within a range of 8 to 12 MOhm thus indicate that the test has been passed.
In the event of an error, the actual defect, i.e. core short-circuiting, core interruption, core
reversal or too little insulation, must be determined. Do not touch the connector plugs of long
extension cables after testing, because they may be electrically charged.
8
Continuity Test with Extra-Low Voltage
Objects can be tested for continuity with the help of the “Durchgang” (continuity) indicator
lamp (10). Connect the DUT to the two connector sockets (11) to this end. Testing is
conducted with safety extra-low voltage of no greater than 33 V AC.
9
Display and Indicators at the Test Instruments
METRATESTER 5+ Display and Indicating Devices
PE Indicator Lamp
Indicates whether or not voltage is present.
Error Lamp
The red error lamp indicates exceeded limit values when measuring protective conductor
current, insulation resistance, equivalent leakage current, contact current, leakage current
and differential current.
Piezo Buzzer
In the event that the error lamp lights up in order to indicate that the respective, critical limit
value has been exceeded, the buzzer also generates an acoustic signal.
9.1
Indication of Errors and Limit Values
Error Message
Condition
PE Indicator Lamp
Mains protective conductor potential
U
B
≥
25 V
When the contact surface is
touched