holthausen
elektronik GmbH
Electronic Vibration Monitoring Unit
ESW
®
-Compact-Alu (hol610)
5. Grounding concept
If an isolated installation is not specially requested, usually through the attachment with
screws each case is connected to the local machine ground.
Inside the ESW
®
-Compact-Alu unit, dependent on customer request the cable shield
and / or the signal ground to the case potential could be connected by the factory.
Connection to the local ground
The Standard delivery condition for ESW
®
-Compact-Alu is that, shielding of the
connection cable is
not
connected
to the case of the unit.
Connection is
not
implemented to the local ground
Inside the optional plug box, the cable shielding, the box ground and the signal ground
could be connected by choice and dependent on local circumstances and
requirements.
In big facilities with considerable energy consumption and distances between the
machines could such big potential difference be build up, that substantial balancing
current on the ground network will occur. Dependent on intensity of such currents is
arising of interference’s or damaging of the unit the result!
Potential differences could also arise on machines, with small distances not clear
crossing of ground potential for example painted color or movable parts like suspension
mounting.
Energetic high frequency interference energy could be added to the measurement
signal-wire by inductivity or trough capacity that could change the real existing
measurement value! In this way, for example parallel going elements could act as
coupling-capacitor and winded up grounding cable could act like a cut off choke.
Memorize: Ground is not equal everywhere!
Check the situation
Plan the grounding concept
Select the facility / realization
6
local
connection box ground
optional
connection box
vibration control unit ground
local
vibration control unit ground
signal ground
vibration
control unit
shield
-Ub
connection box ground
signal ground
main control
box ground
local
main control box ground
shield
main control box
with power supply
+Ub
