Power Supply; Overcurrent Protection; Isolation - WAGO -I/O-SYSTEM 750 Manual

26 System Description
3.6

Power Supply

3.6.1

Overcurrent Protection

Possible fire hazard due to insufficient overcurrent protection!
In the event of a fault, insufficient overcurrent protection can present a possible
fire hazard. In the event of a fault, excessive current flow in the components can
cause significant overheating. Therefore, you should always dimension the
overcurrent protection according to the anticipated power usage.
The system and field voltage of the WAGO-I/O-SYSTEMs 750 is supplied on the
head stations and bus supply modules.
For components that work with extra low voltage, only SELV/PELV voltage
sources should be used.
A single voltage source supplying multiple components must be designed
according to the component with the strictest electrical safety requirements.
For components which are only allowed to be supplied by SELV voltage sources,
these requirements are listed in the technical data.
Most components in the WAGO-I/O-SYSTEM 750 have no internal overcurrent
protection. Therefore, appropriate overcurrent production must always be
implemented externally for the power supply to these components, e.g. via fuses.
The maximum permissible current is listed in the technical data of the
components used.
3.6.2

Isolation

Within the fieldbus node, there are three electrically isolated potentials:
• Electrically isolated fieldbus interface via transformer
• Electronics of the fieldbus couplers/controllers and the I/O modules (local
bus)
• All I/O modules have an electrical isolation between the electronics (local
bus, logic) and the field electronics. Some digital and analog input modules
have each channel electrically isolated, please see catalog.
Manual
1.5.0
750-882 Media Redundancy ETHERNET Controller
WAGO-I/O-SYSTEM 750