Pepperl+Fuchs VIM62PP-E1V16-0PE-I420V15 Manual page 16

VIM6* Vibration Sensors
Installation
Grounding Concept 2 (Special Case)
Only applicable for:
• Plug versions with connection cable accessories from third-party suppliers.
• Assumption: The sensor housing and the cable shield are connected.
Situation/Requirements of
the Application
Severe EMC interference is
expected from the machine
side,
e.g., from the frequency
inverter
Risk/prevention of earth loops
necessary,
e.g., when using a long cable
approx. 500 m in length.
Coupled interference must be
deflected
Table 3.2
The following diagram only applies to plug versions that are used with a commonly available
cordset to connect the sensor housing potential and the cable shield. The EMC adapter (red)
must also be used as an accessory. This grounding concept is recommended when sources of
EMC pollution, such as frequency inverters, are present on the machine side.
Figure 3.2
1 Machine earth
2 Control interface (measuring instrument, PLC, etc.)
3 4 mA ... 20 mA power signal
4 10 V DC ... 30 V DC
5 Cable shield
6 Ground potential for the control interface
7 EMC adapter
In principle, there is a risk that very long cable lengths with a long distance between the
machine earth (1) and the earth (6) of the control interface could lead to an earth loop. This
would lead to continuous equipotential bonding between the machine and the control interface.
To prevent these earth loops, the housing potential and the cable shield are not connected in
this grounding concept.
This separation is implemented using an insulating EMC adapter (red). The sensor is therefore
protected from couplings from the machine side. Nevertheless, further coupled interference
can discharge away or discharge via the earth of the control interface (6).
16
Effects of the Grounding Concept
The machine and the sensor housing should not be con-
nected. Insulation via an EMC adapter protects the sensor's
measurement data acquisition from interference.
The sensor housing and the mounting point on the machine
are not connected:
This means that there is no continuous connection between
the machine earth (-> point 1 in Fig.) and the earth at the con-
trol interface (-> point 6 in Fig.).
Deflected via earth at the control interface (-> point 6 in Fig.)
10-30V
0 V
500 Ω max.