Calculation Of Power Loss; Calculation Of Power Loss For Use In A Potentially Explosive Atmosphere - Emerson PACSystems RSTi-EP User Manual

User Manual
GFK-2958J
Module Part
I
SYS
no. number
10 A is supplied by the EP-7641 module. The 1.81 A calculated as remaining after the 10th module must not
be added to the 10 A after the EP-7641 module!

Calculation of Power Loss

The power loss of the network adapter is calculated as follows:
Pnetwork adapter = P0 + N * Pmod + Iin * ΔUin + Iout * ΔUout
P
P
ΔV
The power loss of a RSTi-EP station is calculated using the power loss of the network adapter
and the power loss of the individual modules. It depends on the current in both current
paths. It is assumed that there is a maximum power loss of 2 watts for the module
Maximum values were assumed for these calculations. If you need detailed calculations,
please
https://www.emerson.com/Industrial-Automation-Controls/support.
P
station
Calculation of Power Loss for Use in a Potentially
Explosive Atmosphere
The module specific data, needed to calculate the output power loss, is provided in the ATEX
certificate which you can download from
Automation-Controls/support.
Configuration
Simultaneity
factor
I I I I
IN OUT S L
g
P Static power loss in the network adapter
0
N
Power loss due to module supply from the system
mod
Maximum power loss module
module
I Current fed in through the input current path
in
Voltage drop across the contacts in the input current
ΔV
in
I Current fed in through the output current path
out
Voltage drop across the contacts in the output current
out
contact Emerson
= P + N * P
network adapter module
Cumulative
Cumulative
current
current
demand of the
demands of
output power
the input
path network
current path
adapter
Number of modules
current path
path
path
technical support
https://www.emerson.com/Industrial-
Chapter 3
Oct 2019
Cumulative
current
demand of
the EP-7641
output power
path
2.3 W
0.02 W
0.18 V
0.18 V
or Global Care
29