User manual - METER SRT-147
–
Use of screened signal cables is recommended. Signal cable screens should be
connected to the earthing only at one of the ends of the screened cable.
–
In the case of magnetically induced interference the use of twisted pair of signal cables is
recommended. Twisted pair (best if shielded) must be used with RS-485 serial
transmission connections.
–
In the case of measurement or control signals are longer than 30m or go outside of the
building then additional safety circuits are required.
–
In the case of interference from the power supply side the use of appropriate interference
filters is recommended. Bear in mind that the connection between the filter and the unit
should be as short as possible and the metal housing of the filter must be connected to
the earth with the largest possible surface. The cables connected to the filter output must
not be run with cables with interference (e.g. circuits controlling relays or contactors).
Connections of power supply voltage and measurement signals are executed using the
screw connections on the back of the unit’s housing.
Figure 4.4. Method of cable insulation replacing and cable terminals
All connections must be made while power supply is disconnected !
Figure 4.5. Terminals description (relay outputs)
11
!
6-7 mm
m
ax
.
2
m
m
1
2
11 12 13 14 15 16 17 18 19
3 4 5 6
7 8 9 10
(optional)
R1
(optional)
R2
(optional)
R3
(optional)
R4
+
Uo
-
+24V
+5%, -10%
I
max = 100mA
RS - 485
DATA+
DATA-
GND
Power
supply
(depending on version)
16 17 18
Pt100/500/1000
Pt100/500/1000
n.c.
