Atex & Iecex Marking; Spring-Style System Cabling; Current Demand And Power Supply; Power Supply Derating - Emerson PACSystems RSTi-EP User Manual

User Manual
GFK-2958J
ATEX & IECEx Marking
Ex nA IIC T4 Gc, IECEx ULD 16.0022X
Ta: -20 °C to +60 °C
For Relay Modules:
Ex nA nC IIC T4 Gc, IECEx ULD 16.0022X
Ta: -20 °C to +60 °C
3.4

Spring-Style System Cabling

RSTi-EP modules (except HD modules) and network adapters are equipped with the spring-
style connector system. Single-strand and fine-strand lines with wire-end ferrules can be
inserted without the need for a tool. Lines with a cross-section measuring between 0.14
mm2 and 1.5 mm2 (AWG 26 – 16) can be connected.
The external dimensions of the crimped wire-end ferrules must conform to IEC‑60947-1.
3.5

Current Demand and Power Supply

The RSTi-EP system uses three internal current paths:
The ISYS system current path supplies the communication part of the I/O modules; it is fed
from the network adapter input supply and cannot be interrupted by any module. The
maximum current-carrying capacity of ISYS allows a RSTi-EP station to be expanded with a
maximum of 64 active modules without having to refresh the power.
The IIN input current path supplies the input circuit of the input modules as well as the
connected IS sensors. The current must be refreshed with EO-7631 (power feed in) modules
as required. These EP-7631 modules isolate the input current path towards the left (towards
the network adapter), and as a result start a new electricity segment towards the right.
The IOUT output current path supplies the output circuit of the output modules with power,
as well as the connected IL actuators. The current must be refreshed with the EP-7641
(power feed-out), as required. These EP-7641 modules isolate the output current path to
the left (towards the network adapter), and as a result start a new electricity segment to the
right.
Note:

Power Supply Derating

The power supply is restricted according to the temperature. The following values apply for
the horizontal and vertical positioning of the RSTi-EP station:
Configuration
II 3 G Ex nA IIC T4 Gc, DEMKO 16 ATEX 1591X
II 3 G Ex nA nC IIC T4 Gc, DEMKO 16 ATEX 1591X
The design of the power supply being used must take start-up peaks into account.
Chapter 3
Oct 2019
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