OMICRON 35
Step and touch voltage measurements
As an example, Figure 8-12 below shows the touch voltage measurement according to IEEE 81.
Figure 8-12: Touch voltage measurement with PTM (tablet) according to IEEE 81
Table 8-2: Step and touch measurements according to EN 50522 and IEEE 81
Standard Measurement Ground electrode
Input imped.
EN 50522:2011 Touch voltage 20 cm X 20 cm metal plate loaded with min. 50 kg,
1 m apart from grounded structure. Wetten the soil
underneath the plate.
1kΩ
1
1. This standard also proposes to consider additional resistances for the assessment of the measurement, which requires a high
ohmic input impedance.
Step voltage This standard assumes that the limits for step
voltage are much higher than for touch voltage.
Therefore, step voltage measurements are
considered obsolete.
-
IEEE 81-2012 Touch voltage Rod (6 mm diameter) driven 150 mm into moist
subsoil, 1 m apart from grounded structure.
High Z
Step voltage Two rods (6 mm diameter) each driven 150 mm into
moist subsoil, 1 m apart from each other.
High Z
Test probe
Ground rod (6 mm
diameter) driven 150
mm into moist subsoil,
1 m apart from
grounded structure
To Next Page
Loading...
Need help?
General
