Spur Voltage Limited By The External Fieldbus Power Supply Uo  24V, Entity Examination; Spur Voltage Limited By The Segment Protector - Pepperl+Fuchs R2-SP-IC Series Manual

Segment Protector
Hazardous Area Installation and Use
3.2.1 Spur Voltage Limited by the External Fieldbus Power Supply U
Entity Examination
When using intrinsically safe fieldbus power supplies to directly limit the spur output safety
voltage, it is necessary to pay particular attention to the type of fieldbus power supply selected
for use with the Segment Protector. This determines the type of Zone 2 or Div. 2 installations
and the certified field devices that can be connected, in the Zone 2 or Div. 2 area, to the spurs
of the Segment Protector.
A check must be performed to ensure that the correct type of power supply module is used for
the required safety output parameters. For example, the output voltage must be equal to, or
less than the maximum voltage of the connected field devices.
When a power supply with U
groups IIC, IIB, IIA at the spurs are:
R2-SP-IC* allowed safety output values:
Uo = 24 V, Io = 65 mA, Lo = 0.25 mH, Co = 60 nF (switch 1 in position 2).
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The safety evaluation follows the Entity model defined in EN 60079–11.
Requirements for typical fieldbus products for use in Zone 2 installations are summarized in the
manual: 'Using Pepperl+Fuchs fieldbus equipment in Zone 2 hazardous area environment.
This document is supplied separately and can be obtained from Pepperl+Fuchs Internet
product database.
3.2.2

Spur Voltage Limited by the Segment Protector

The fieldbus trunk is rated as non-sparking Ex nAc. Live maintenance at the trunk is only
permitted with a hot work permit. The Segment Protector includes an internal voltage limitation
in accordance with IEC 60079–25, using a maximum output voltage level of U
internal voltage limitation of U
related to the gas group in which the Segment Protector will be installed.
A switch determines the setting of two different maximum short circuit currents, one for gas
group IIC, and one for gas group IIB. The spur outputs are rated as intrinsically safe Ex ic.
Danger!
Risk of explosion through sparking
Using operating elements in a potentially explosive atmosphere can cause sparks that can
ignite the surrounding atmosphere.
Only use operating elements (e.g., switch, slider, button, etc.) in the absence of a potentially
explosive atmosphere.
Danger!
Risk of explosion through material damage of an operating element
Using operating elements outside of the specified ambient temperature range can lead to
material damage, e.g., increased porosity, etc. resulting in an unwanted failure of the
functionality of the element. This can result in an increased explosion hazard in potentially
explosive atmospheres.
Only use operating elements in the specified ambient temperature range.
Temperature range: -5 C° ... +70 C°
 24 V is used, the resulting allowed safety output values for gas
o
 32 V is used, it is required to determine the hazardous location
o
 24V,
o
 32 V. If the
o
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