Operation Manual

GMC-I Messtechnik GmbH 25
Table for the determination of maximum display values for low resistances by
making allowances for the instrument’s measuring error.
12 List of Abbreviations and their Meanings
Voltage
U Test voltage or nominal voltage
U
ISO
Rising test voltage for insulation testing
U~ Measured voltage (sinusoidal alternating voltage)
Temperature / Atmospheric Humidity
T /  Temperature
F
REL
Relative atmospheric humidity
Resistance, Contact Current
LIMIT Limit value for insulation resistance, low-value resistance or
contact current
Offset Correction value of resistance for measurement cables
R
INS
Insulation resistance
R
LO
Low-value resistance (cable resistance)
13 Maintenance
13.1 Self-Test
Ð The self-test is started from the main menu with the Tes t key. The test
has a duration of several seconds.
The following information is displayed in the two headers:
Type/Cal: Device type / date of last calibration
Version: Software version and issue date
Self-tests for the items Chksum through LED are performed automatically,
one after the other, and are checked off or marked with a horizontal dash
if they are not passed.
Chksum1/2: Status display for internal testing (Each test must be
completed with a check mark. If not, the measuring and
test instrument may no longer be used. Please contact our
service center in this case.)
Relays: Each relay is switched twice.
LED: The U, LIMIT and NETZ/MAINS lamps each blink twice in red.
The PE lamp cannot be tested automatically!
As soon as the tests in the left-hand column have been completed, the
following tests must be started manually:
Limit Value
Maximum
Display Value
Limit Value
Maximum
Display Value
0.15  0.11 
0.20  0.16  5.00  4.72 
0.50  0.44  10.0  9.47 
1.00  0.92  20.0  17.7 
2.00  1.87  50.0  44.7 