Datasheet
3
265
3
▯ = ON
857-552
L1
RT 500
4 ... 20 mA
DIP Switch Adjustability
Default Setting
All DIP switches are in “OFF“ position for delivery.
Input
Input Signal
RC1 500 A
Measuring Method Mean square value
Filter not active
Output
Output Signal 0 ... 20 mA
Measuring Range Underfl ow 0 mA
Measuring Range Overfl ow 20.5 mA
Overcurrent 21 mA
Digital Output DO not active
DIP Switch S1
DIP Switch S1
Measuring Range Underfl ow Measuring Range Overfl ow
Overcurrent
(Input Signal - End Value + 20%)
Digital Output DO
Signaling
78 910
(+20 %) Upper limit of measuring range +2.5 %
*
Upper limit of measuring range +5 %
*
DO not active
● Lower limit of measuring range Upper limit of measuring range +2.5 % Upper limit of measuring range +5 % ● DO U
s
+ switching
● Lower limit of measuring range Upper limit of measuring range Lower limit of measuring range ● ● DO GND switching
● ● Lower limit of measuring range Upper limit of measuring range Upper limit of measuring range
Input Signal RC Confi guration Input Filter Output Signal
12 3 456
RC1 = RT500 from LEM RC2 = RT2000 from LEM off 0 ... 20 mA
● RC2 ● RC2 = 100 mV eff . => 1 kA ● active
● 4 ... 20 mA
● 0 ... 10 V
● ● 2 ... 10 V
● 0 ... 10 mA
● ● 2 ... 10 mA
● ● 0 ... 5 V
● ● ● 1 ... 5 V
*
acc. to NAMUR NE 43
Application example:
The digital output (DO) signals error messages and can be confi gured as follows: 24 V → 0 V/0 V → 24 V.
In order to increase the switching current of the DO, the latter may be expanded by a relay. Thanks to the contour uniformity of Series 857, for example, a 857-304
Relay can be snapped in next to it. This output can be quickly and easily expanded to a switching current of 6A by simply using an adjacent jumper (859-402).
Digital Output DO/Signaling
Filter
The fi lter function allows a low-pass fi lter to be switched on in order to mask or “smooth out” oscillating measured values
(e.g., during trailing edge fl ows).
Switching Behavior, Digital Output (DO)
DO
%
DO‘
t
100
!
!
75
0
0
0
configured
to 75 %
Measuring
input/
Measured
value
default
! Hysteresis
DO/
LED indication
24 V/500 mA
PLC/
LED indication
e.g. 787-1002
16.8 ... 31,2 V
230 VAC