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ENGLISH
General safety advice for users
• If the device is permanently connected, its electrical installation must include a device
to isolate it from the power supply and a circuit-breaker to protect it against overcurrents
and isolation faults. If this is not the case, the power socket must be grounded and be
easily accessed. The device must be connected to the protective ground.
• If the device is supplied with 24 or 48 VDC, the low voltage circuits must be protected.
Only use power supplies which conform to the standards currently in force.
• Check that the supply voltages remain within the tolerance ranges defined in the
technical characteristics of the devices.
• All measures must be taken to ensure that any power return (immediate, warm or cold)
does not lead to a dangerous state which may place personnel or the installation at
risk.
• Emergency stop devices must remain effective in all the device's operating modes,
even those which are abnormal (for example, when a wire becomes disconnected).
Resetting these devices must not cause uncontrolled or improper restarts.
• Cables which carry signals must be located where they do not cause interference with
the control system functions by capacitative, inductive or electromagnetic interference.
• Control system equipment and their control devices must be installed in such as way
as to ensure that they are protected against unintentional operation.
• Appropriate safety measures must be taken for the inputs and outputs, to prevent
improper states in the control system device, if no signal is received.
6 Equipment operation
The operational safety and availability of a device is its ability to avoid the appearance
of faults and to minimize their effects if they occur.
A fault inside the control system is known as :
• passive, if it results in an open output circuit (no command is sent to the actuators).
• active, if it results in a closed output circuit (a command is sent to the actuators).
From the safety point of view, a given fault is dangerous or not depending on the type
of command given during normal operation. A passive fault is dangerous if the normal
command is the operation of an alarm. An active fault is dangerous if it maintains or
activates an undesirable command.
The system designer must use devices external to the PLC to protect against active
faults inside the PLC, whether they are indicated or not.
7 Electrical and thermal characteristics
Details of the electrical and thermal characteristics of devices are given in the associated
technical documents (installation manuals, service instructions).
8 Maintenance
Troubleshooting procedure
• Control system equipment should only be repaired by qualified personnel (after sales
service engineer, or technician approved by Schneider Automation SA). Only certified
replacement parts or components should be used.
• Before performing any operation on equipment, always cut the power supply off and
mechanically lock any moving parts.
Replacement and recycling of used batteries
Use batteries of the same type as the originals and dispose of defective batteries in the
same way as toxic waste.
