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VOLTAGE OUTPUTS FOR SSR DRIVE
Fig. 8 SSR DRIVE OUTPUT WIRING
It is a time proportioning output.
Logic level 0
: Vout < 0.5 V DC.
Logic level 1
:
- 14 V + 20 % @ 20 mA
- 24 V + 20 % @ 1 mA.
Maximum current = 20 mA.
NOTE
: This output is not isolated.
A double or reinforced Isolation between instrument
output and power supply must be provided by the
external solid state relay.
SOLID STATE
RELAY
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 but
the OUT 1 NC contact is not protected.
The same problem may occur when a switch is
used in series with the internal contacts as shown
in Fig. 7.
Fig. 7 EXTERNAL SWITCH IN SERIES WITH
THE INTERNAL CONTACT
In this cases it is recommended to install an
additional RC network across the external contact
as show in Fig. 7 (Chromalox snubber PN 0149-
01305 is recommended).
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
+
_
_
+
8
7
OUT 1
LOAD
C
R
POWER
LINE
1601-1-0C.p65
5/2/00, 1:45 PM
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