15
Load resistance diagram
KFF - xx ⁄ KFTF - xx
4...20 mA
800
700
600
500
400
300
250
50
200
10
15
20
25
30 35 36 40
Load resistance diagram
W
orking r
esis
tanc
e (Ohm)
Operating voltage (V DC)
Admissible
range
800
700
600
500
400
300
250
50
200
10
15
20
25
30 35 36 40
Load resistance diagram
W
orking r
esis
tanc
e (Ohm)
Operating voltage (V DC)
Admissible
range
NOTE
For 4 ... 20 mA devices, DC voltage must be used
(without residual ripple, see permissible range of load
resistance diagram). Do not use pulsating DC voltage.
Connecting diagram
KFTF - xx - U
Output:
with ⁄ without
0 -10 V
Display
Connecting diagram
KFTF - xx - I
Output:
with ⁄ without
4 ... 20 mA
Display
NOTE
At transmitters with current output the humidity output (Pin 2)
must categorically be connected !
1 2 3 4
230V AC
24V AC/DC
PLC
PC
+U
B
24
V
AC
/D
C
O
ut
pu
t h
um
id
ity
in
%
r.H
. 0
-1
0V
O
ut
pu
t t
em
pe
ra
tu
re
in
°C
0-
10
V
–UB
-GN
D
1 2 3 4
230V AC
24V DC
+U
B
24
V
D
C
O
ut
pu
t h
um
id
ity
in
%
r.H
. 4
...
20m
A
O
utp
ut
tem
per
at
ur
e
in
°
C
4
...
20m
A
PLC
Working
resistance
–UB GND (optional f
or
LCD back
gr
ound lightling)
Connecting scheme
Parallel operation
Connecting scheme
Individual operation
SUPPLY VOLTAGE:
For operating voltage reverse polarity protection, a one-way rectifier or
reverse polarity protection diode is integrated in this device variant.
This internal one-way rectifier also allows operating 0 - 10 V devices on AC
supply voltage.
The output signal is to be tapped by a measuring instrument. Output volt-
age is measured against zero potential (O V) of the input voltage!
When this device is operated on
DC supply voltage
, the operating voltage
input UB+ is to be used for 15...36 V DC supply and UB – or GND for ground
wire!
When several devices are supplied by one 24 V
AC voltage supply
, it is to
be ensured that all ”positive“ operating voltage input terminals (+) of the
field devices are connected with each other and all ”negative“ operating
voltage input terminals (–) (= reference potential) are connected together
(in-phase connection of field devices). All outputs of field devices must be
referenced to the same potential!
In case of reversed polarity at one field device, a supply voltage short-
circuit would be caused by that device. The consequential short-circuit
current flowing through this field device may cause damage to it.
Therefore, pay attention to correct wiring!
Circuitry
Circuitry
0...10V
0V/GND
0...10V
0V/GND
Power supply
AC 24V~
0V
DC 15-36V = GND
Circuitry
0...10V
0V/GND
V
Power supply
AC 24V~
0V
DC 15-36V = GND
G
HYGRASGARD
®
KFF ⁄ KFTF (± 2,0 %), KFF - 20 ⁄ KFTF - 20 (± 1,8 %)
