Wiring Precautions

Introduction

In order to protect the signal from outside interference induced in series mode and interference in common mode, we recommend that you take the following precautions.

Cable Shielding

Connect the cable shielding to the grounding bar. Clamp the shielding to the grounding bar on the module side. Use the shielding connection kit BMXXSP•••• to connect the shielding.

DANGER

HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH

While mounting / removing the modules:

make sure that each terminal block is still connected to the shield bar and
disconnect voltage supplying sensors and pre-actuators.

Failure to follow these instructions will result in death or serious injury.

Reference of Sensors in Relation to the Ground

In order for the acquisition system to operate correctly, we recommend you take the following precautions:

sensors must be close together (a few meters)
all sensors must be referenced to a single point, which is connected to the PLC’s ground

Using Sensors with non Isolated Inputs

The inputs of the module are not isolated between them and single ended type. They do not admit any common mode voltage. The sensors are connected as indicated in the following diagram:

If one or more sensors are referenced in relation to the ground, this may in some cases return a remote ground current to the terminal block and disturbs the measures. It is therefore essential to follow the following rules:

Use isolated from ground sensors if distance from sensors is > 30 meters or if power equipments are located near PLC.
The potential must be less than the permitted low voltage: for example, 30 Vrms or 42.4 VDC between sensors and shield.
Setting a sensor point to a reference potential generates a leakage current. You must therefore check that all leakage currents generated do not disturb the system.

Using Pre-Actuators Referenced in Relation to the Ground

There are no specific technical constraints for referencing pre-actuators to the ground. For safety reasons, it is nevertheless preferable to avoid returning a remote ground potential to the terminal; this may be very different to the ground potential close by.

Sensors and other peripherals may be connected to a grounding point some distance from the module. Such remote ground references may carry considerable potential differences with respect to local ground. Induced currents do not affect the measurement or integrity of the system.

DANGER

HAZARD OF ELECTRIC SHOCK

Ensure that sensors and others peripherals are not exposed through grounding points to voltage potential greater than acceptable limits.

Failure to follow these instructions will result in death or serious injury.

Electromagnetic hazards instructions

WARNING

UNEXPECTED EQUIPEMENT OPERATION

Follow those instructions to reduce electromagnetic perturbations:

adapt the programmable filtering to the frequency applied at the inputs,
use the shielding connection kit BMXXSP•••• to connect the shielding,
use a specific 24 VDC supply to sensors and a shielded cable for connecting the sensors to the module.

Electromagnetic perturbations may cause the application to operate in an unexpected manner.

Failure to follow these instructions can result in death, serious injury, or equipment damage.