Super Systems 7EK 31081 - Manual (Page 9)

4
18
NO - OUT 4
19
NO - OUT 3
C - OUT 3/4
20
OUT 3
OUT 4
22
OUT 2 21
C
NO
INDUCTIVE LOADS
High voltage transients may occur when switching
inductive loads.
Through the internal contacts these transients may
introduce disturbances which can affect the performance
of the instrument.
The internal protection (varistor) assures a correct protection
up to 0.5 A of inductive component.
The same problem may occur when a switch is used in
series with the internal contacts as shown in Fig. 8.
Fig. 8 EXTERNAL SWITCH IN SERIES WITH THE
INTERNAL CONTACT
In this case it is recommended to install an additional RC
network across the external contact as show in Fig. 10
The value of capacitor (C) and resistor (R) are shown in
the following table.
Anyway the cable involved in relay output wiring must be
as far away as possible from input or communication
cables.
LOAD
(mA)
<40 mA
<150 mA
<0.5
A
C
( m F)
0.047
0.1
0.33
R
( W )
100
22
47
P.
(W)
1/2
2
2
OPERATING
VOLTAGE
260 V AC
260 V AC
260 V AC
C) RELAY OUTPUTS
Fig. 7 RELAY OUTPUTS WIRING
All relay outputs are protected by varistor against inductive
load with inductive component up to 0.5 A.
The contact rating of the OUT 2 is 3A/250V AC resistive
load.
The contact rating of the OUT 3 and 4 is 2A/250V AC
resistive load.
The number of operations is 1 x 10
5 at specified rating.
The following recommendations avoid serious problems
which may occur, when using relay output for driving
inductive loads.
NOTES:
1) To avoid electrical shock, connect power line at last.
2) For supply connections use No 16 AWG or larger wires
rated for at last 75 °C.
3) Use copper conductors only.
4) Don’t run input wires together with power cables.
R
C
LOAD
POWER
LINE
31081-1-00.p65 3/24/00, 11:59 AM 4