VEGA KFD0-SCS-Ex1.55 User Manual

SMART repeaters

KFD0-SCS-Ex1.55

Field circuit EEx ib IIC

Transmission range 4 mA ... 20 mA

• 1-channel

• Field circuit EEx ib IIC

• Loop powered

• Lead monitoring

• Conductive for HART communication
(galvanically isolated)

• Universal application for transmitters,
position controllers and I/P
converters

• Only 5 V voltage drop

• Test sockets for HART

• EMC acc. to NAMUR NE 21

Function

The universal module
KFD0-SCS-Ex1.55 does not require
auxiliary power for the isolation of
4 mA ... 20 mA current loops. It is
therefore, low in cost and has a
noticeably low power loss as compared
to active isolator modules. The module
isolates 4 mA ... 20 mA signals from
transmitters and positioners and is
therefore, bidirectionally HART
compatible. The HART transmitters and
HART positioners may thus, be
configured in the safe area as well as
the hazardous area. The low 5 V
voltage drop also allows for transmitter­applications with unstable power
sources in the range of
20 V DC ... 30 V DC.
In addition, the voltage drop across the
resistance (load) of the active
measurement input must be considered
when calculating the field voltage
(terminals 1+ and 2-).
Lead breakage monitoring is possible
by means of the reaction of the field
current signal to the safe area, which
means the control system must monitor
whether the 4 mA ... 20 mA range was
exceeded or fallen short of.
The module may also be used for
controlling Ex-i valves, light signals, etc.
based on the internal voltage limits
(safe area). Terminals 8- and 9+ in this
case are driven with a 24 V binary
signal.

Transmitter
Positioner
I/P converter

3-

Current source
4 mA ... 20 mA

or

Voltage supply

Composition

?

I

2-

2- 1+

2-

2- 1+

2-

8- 9+

8-

8-

8- 9+

Measuring resistors

SMART

communicator

1+

U/I

33 V

50 mA

9+

SMART

communicator

9+

Supply circuit

Safe area Hazardous area

122609_ENG.xml 2003-03-25

Subject to reasonable modifications due to technical advances. Copyright Pepperl+Fuchs, Printed in Germany

1

Pepperl+Fuchs Group • Tel.: Germany [phone] • USA [phone] • Singapore [phone] • Internet http://www.pepperl-fuchs.com

Technical Data

Supply

Power loss 0,2 W

Field circuit

Connection terminals 1+, 2 / 3-
Available voltage ≥ 16 V for supply voltage > 21 V
Current 4 ... 20 mA (linear transmission 1 ... 22 mA)
Load ≤ 800 Ohm (at 20 mA)

Supply circuit

Connection terminals 8-, 9+
Safety maximum voltage U

Voltage max. 30 V DC
Current 4 ... 20 mA (quiescent current < 0.5 mA)
Power loss 150 mW at 20 mA and UE < 24 V

Transfer characteristics

Voltage drop see note
Deviation

After calibration ≤ ± 80 µA linearity, load and voltage dependence at 20 °C (293 K)
Temperature < 0.5 µA/K
Damping approx. 3 dB
Rise time ≤ 20 µs at 0 Ohm, ≤ 600 µs with 800 Ohm load

Electrical isolation

Input/Output safe electrical isolation acc. to EN 50020

Standard conformity

Coordination of insulation acc. to DIN EN 50178
Electrical isolation acc. to DIN EN 50178
Electromagnetic compatibility acc. to EN 50081-2 / EN 50082-2, NAMUR NE 21
Climatic conditions acc. to DIN IEC 721

Directive conformity

Electromagnetic compatibility standards

Directive 89/336/EG on request

Ambient conditions

Ambient temperature -20 ... 60 °C (253 ... 333 K)

Mechanical specifications

Protection degree IP20
Mass approx. 120 g

Data for application in conjunction
with hazardous areas

EC-Type Examination Certificate PTB 02 ATEX 2064 ; for additional certificates see www.pepperl-fuchs.com

Group, category, type of protection ¬ II (2) G [EEx ib] IIC

Voltage U0 23,1 V DC

Current I0 28 mA

Power P0 0,647 W

Type of protection [EEx ib]

Explosion group IIC

External capacitance 0,096 µF

External inductance 0,5 mH
Electrical isolation

Input/Output safe electrical isolation acc. to EN 50020
Directive conformity standards

Directive 94/9 EU on request

m

253 V

KFD0-SCS-Ex1.55

122609_ENG.xml 2003-03-25

Subject to reasonable modifications due to technical advances. Copyright Pepperl+Fuchs, Printed in Germany

Pepperl+Fuchs Group • Tel.: Germany [phone] • USA [phone] • Singapore [phone] • Internet http://www.pepperl-fuchs.com

2