Super Systems 3 Series - Manual (Page 11)

Series 3 Operations Manual
11
2.9 Output 4 (AA Relay)
Output 4 is a relay..
For output functions, see Quick Start Code in section 4.1.1.
Relay Output (Form C)
• Contact rating: 2A 264Vac resistive
2.10 General Note About Relays and
Inductive Loads
High voltage transients may occur when switching inductive
loads such as some contactors or solenoid valves. Through
the internal contacts, these transients may introduce
disturbances which could affect the performance of the
instrument.
For this type of load it is recommended that a ‘snubber’ is
connected across the normally open contact of the relay
switching the load. The snubber recommended consists of a
series connected resistor/capacitor (typically 15nF/100Ω). A
snubber will also prolong the life of the relay contacts.
A snubber should also be connected across the output
terminal of a triac output to prevent false triggering under
line transient conditions.
WARNING
When the relay contact is open or it is connected to a high
impedance load, the snubber passes a current (typically
0.6mA at 110Vac and 1.2mA at 240Vac). You must ensure
that this current will not hold on low power electrical
loads. If the load is of this type the snubber should not be
connected.
2.11 Digital Inputs A & B
Digital input A is an optional input in model Series 3. Digital
input B is always fitted in model Series 3.
• Not isolated from the current transformer input or the
sensor input
• Switching: 12Vdc at 40mA max
• Contact open > 500Ω. Contact closed < 200Ω
• Input functions: Please refer to the list in the quick
codes.
2.12 Transmitter Power Supply
The Transmitter is fitted as standard in model Series 3.
• Isolated output 240Vac CAT II
• Output: 24Vdc, +/- 10%. 28mA max.
• inside the controller
Dig in A
C
LA
OP4
AA
AB
AC
Dig in B
LB
LC
24Vdc
Transmitter Supply
3C
3D