Page 2
Terminal Connections
Input
1
Transducer supply (+)
or optional Second Input (+)
2
Input Signal (+)
3
Input Signal Common (–)
Channel A
4
SPCO Normally Closed
5
SPCO Common
6
SPCO Normally Open
7
SP Common
8
SP Normally Open
Channel B
9
SP Normally Open
10 SP Common
11 SPCO Normally Open
12 SPCO Common
13 SPCO Normally Closed
Supply
14 Earth
15 Neutral
16 Line
Operation
The output relays of the dual trip amplifier
change state when the input signal
passes the points set on the front panel
mounted ‘Trip Point’ controls.
Single Input
The unit is normally connected internally
to be driven from one input signal.
Current input types are calibrated with a
signal input conditioning resistor which is
installed between terminals 2 and 3
(Input ‘A’ position) in the base section of
the module.
Please note
On early releases of this unit, the transducer
supply is not available. These units are
identified by “112-2A-080” on the PCB
adjacent to hysteresis pots.
Two Input Option
Where two separate inputs are specified,
the transducer supply is not available but
is replaced by a connection for a second
input signal. Each ‘channel’ is calibrated
to its respective input signal. Channel A
input signal connects to Terminal 1.
Current Inputs
For current inputs, when the plug-in
module is removed, signal loops are
maintained via a shunt resistor mounted
in the base section of the module. The
unit and its shunt resistor(s) are calibrated
as a matched pair. An error of
£
± 0.1%
can be expected if the instrument is used
with an unmatched input resistor (e.g. by
swapping plug-in modules.).
Front Panel Controls
The front panel controls are scaled
0-100% of the full scale input signal. The
LED indicators illuminate when the
respective relays are energised.
Transducer Supply
(i) Two wire transmitter connections
(ii) Three wire transmitter connections
DC versions only
Earth
Negative (–)
Positive (+)
[+]
[–]
2-wire transducer
[1]
[2]
[Power (+)]
[Ground]
3-wire transducer
[2]
[1]
[3]
[Signal]
