YOKOGAWA CENTUM CS 3000 - Page 41

1. System Installation Requirements
1-29
TI 33Q01J10-01E
Examples of Arrester
The following shows how to install an arrester as a countermeasure against lightning-induced
noise :
GND
I/O
module
AR AR
I/O
module
GND
System side
Field wiring
+
-
AR AR
System side
Field wiring
A
B
B
I/O
module
GND
AR
System side
Field wiring
+
-
AR
Field wiring
: Induced lightning strike point AR: Arrester
F010501.ai
2-wire transmitter/analyzer
Resistance temperature detector
Thermocouple
Power supply
GND
System
2-wire
transmitter
Figure Examples of Arrester Installation
Examples of Spark-killer Installation
The following shows how to install a spark-killer as a countermeasure against inductive load-
caused noise:
Relay contact
Power supply
F010502.ai
Example
R: 120 ohms
C: 0.1 to 0.3 μF
Example
R: 120 ohms
C: 0.1 μF
Spark
killer
CS 3000100 V AC
Fluorescent
lamp or fan
The spark killer prevents noise-
caused equipment failure when
a fluorescent lamp or fan is
turned on or off.
The diode protects the output transistor
from noise occurring during on-to-off
transitions of the relay.
The spark killer protects the output
relay contact.
Diode
Controller
control signal
Spark
killer
24 V DC
Tr
Relay
Figure Examples of Spark-killer Installation
Nov. 20, 2003-00