Meggitt vibro-meter SpeedSys300 ODS301, User Manual

Page: 43 / 170

Document reference MAODS301/E USER MANUAL
Edition 4 - May 2022 SpeedSys300 ODS301 overspeed detection system
3 - 5
Installation considerations
INSTALLATION OF A SPEEDSYS300 ODS301
3.2.4 Shielding
NOTE: Knowledge of the installation of field wiring and protective earth (PE),
instrument earth (IE) and intrinsically safe earth (IS) is required.
For the SpeedSys300 ODS301 module, all electrical connections (wiring) must be installed
with shielded cables. Connect all cable shields in the non-explosive area to instrument earth
at both sides of the cable.
For applications using a 2-wire current sensor (proximity sensor) or a 3-wire voltage sensor
(electronic
sensor), the sensor cable shield has to be connected to
“intrinsically safe earth / GND” (IS) on the SpeedSys300 ODS301 module side. If
disturbances occur and inductive interferences need to be reduced, both sides of the sensor
cable shield can be connected to the “intrinsically safe earth / GND” (IS).
For applications using a 2-wire voltage sensor (magnetic sensor), the SpeedSys300 ODS301
module requires an installation in a controlled electromagnetic (EMC) environment with the
grounding of the sensor cable shield on the module side. Otherwise, both sides of the sensor
cable shield must be connected to “intrinsically safe earth / GND”.
Table 3-1 provides detailed information on the shielding requirements/specifications for the
SpeedSys300 ODS301 module in an EMC/ESD uncontrolled environment.
It is also important to observe the general installation regulations for explosion protection
(see
3.2.7 Installations in hazardous areas ).
A general wiring diagram illustrating the required grounding and shielding for most interfaces
in a typical application in an EMC/ESD uncontrolled area is shown in
3.2.10 General wiring
diagram .
A general wiring diagram for a SpeedSys300 ODS301 overspeed detection system (ODS)
using a TQ9xx-based proximity measurement chain as the input in an EMC/ESD controlled
area is shown in
7 Electrical connections .
See also 3.2.2 Power supply and 3.2.3 Grounding .