Planning Intrinsically Safe Circuits; Planning The Grounding Of The Power Supply - Siemens SIMATIC ET 200SP HA System Manual

Plant planning
4.6 Power supply and potential ratios
4.6.5

Planning intrinsically safe circuits

Safety
Observe the guidelines according to EN / IEC 60079‑14 during configuration.
Basic realization
Intrinsically safe electrical circuit
You must ensure that the connection of an intrinsically safe sensor, actuator or HART field
device to the input/output of an I/O module results in an intrinsically safe circuit.
When you select sensors, actuators and HART field devices to an I/O module, you need to check
the resulting safety-related values.
You can realize a simple, intrinsically safe circuit if you connect an intrinsically safe sensor,
actuator or HART field instrument to an I/O module suitable for hazardous areas according to
regulations.
Information on the assignment of the terminals on the Ex BaseUnit is provided in the
documentation of the I/O module which is plugged/configured on a slot.
Electrical parameters for the safety concept (Page 45)
4.6.6

Planning the grounding of the power supply

Power supply and potential equalization
Ensure that power is supplied to the Ex power module exclusively via an SELV/PELV power supply
unit.
Connect the mounting rail of the station to your local equipotential bonding system.
To ensure intrinsic safety, no connection between the local equipotential bonding system and
the equipotential bonding at the location of the connected field device is specified.
The fundamental requirements for equipotential bonding in explosion-protected areas
according to EN / IEC 60079-14 remain valid to the full extent.
46
WARNING
Modules for devices in a hazardous area
System Manual, 04/2021, A5E50165138-AA