31
TGH 1360E
Wiring and commissioning
The chapter FUNCTIONAL PRINCIPLE already refers to the fact that
symmetrical and asymmetrical insulation faults have to be considered separately.
In particular, asymmetrical faults have to be considered.
If the ratio between the higher and the lower insulation value is greater than 50,
the measured value for the higher insulation resistance insulation will not be
displayed directly. Since in this case the limits of accuracy have been exceeded,
the only indication is: > 50 x RF-.
Example:
UN- = 10 V UN = 700 V
RF- = 20
Ω
RF+ > 1k
Ω
AL- = 50k
Ω
AL+ = 50k
Ω
Menue:
08:45
Indication of
asymmetrical
faults
If the insulation resistance of one conductor falls below 5
Ω
, the shift voltage of
the other conductor is too low to calculate any value. In this case, the LC
display indicates XXXX for this high resistance insulation fault.
Different insulation faults and the respective indications are listed in the table
below:
Value of insulation fault
Indication
Remarks
RF+
RF-
RF+
RF-
20
Ω
100
Ω
20
Ω
100
Ω
Ratio of positive/negative faults is
< 50
20
Ω
15k
Ω
20
Ω
>1k
Ω
Ratio of positive/negative faults is
> 50
15k
Ω
20
Ω
>50k
Ω
20
Ω
Ratio of positive/negative faults is
> 50
1k
Ω
80k
Ω
1k
Ω
>50k
Ω
Ratio of positive/negative faults is
>50
80k
Ω
1k
Ω
>50k
Ω
1k
Ω
Ratio of positive/negative faults is
>50
3
Ω
1k
Ω
3
Ω
xxxx
RF+ < 5
Ω
, => RF value cannot be
determined
1k
Ω
2
Ω
xxxx
2
Ω
RF- < 5
Ω
, => kRF value cannot be
determined
4
Ω
3
Ω
4
Ω
3
Ω
Symmetrical fault: although both
of the values are < 5
Ω
the are
indicated correctly
