GS Chromalox 4081, Руководство по установке и эксплуатации

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Universal / Auxiliary Input 2 Connections
An Auxiliary Input 2 option is fitted to some models.
This can connect to a potentiometer; analogue mA; mV
or V DC signal for a remote setpoint input signal, or for
flow/valve position feedback information. Alternatively,
a second Universal Input 2 option may be fitted. In ad-
dition to the remote setpoint input signal or feedback
information possible with the auxiliary input, the 2nd
Universal Input can be used as a second process con-
trol loop for two control loops, or used in conjunction
with input one in more complex single control loops.
Universal Input 2 can be connected to thermocouples;
resistance temperature detectors; potentiometers; an-
alogue mA; mV or V DC signals.
The settings are in the Input 2 Configuration sub-menu.
Connections for the various types are shown below.
Ensure that the signal is correctly connected, paying
particular attention to the polarity.
Universal Input 2 Connections -
Thermocouple (T/C)
The optional 2nd universal input, supports various
thermocouple types. Supported types & ranges are
listed in the input specifications section on page 245.
Only use the correct thermocouple wire or compensat-
ing cable from the sensor to the instrument terminals
avoiding joints in the cable if possible. Where joints are
made, special thermocouple connectors must be used.
Failure to use the correct wire type and connectors will
lead to inaccurate readings. Ensure correct polarity of
the wires by cross-referencing the colors with a ther-
mocouple reference table.
Figure 14. Input 2 - Thermocouple Connections
Universal Input 2 Connections –
PT100 / NI120 (RTD) Input
The optional 2nd universal input, supports two types of
RTD. PT100 (platinum sensor, 100
Ω
at 0°C). For three
wire RTDs, connect the resistive leg and the common
legs of the RTD as illustrated. For a two wire RTD a wire
link should be fitted across terminals 35 & 36 (in place
of the third wire). Two wire RTDs should only be used
when the leads are less than 3 metres long. If possible,
avoid cable joints.
Figure 15. Input 2 - RTD Connections
Four wire RTDs can be used, provided that the fourth
wire is left unconnected. This wire should be cut short
or tied back so that it cannot contact any of the termi-
nals on the rear of the instrument.
Universal / Auxiliary Input 2 Connections -
Linear Volt, mV or mA input
The optional auxiliary or 2nd universal input supports
the following linear/analogue signals: 0 to 50mV; 10 to
50mV; 0 to 5V; 1 to 5V; 0 to 10V; 2 to 10V; 0 to 20mV;
4 to 20mA from any suitable source. Voltage & milli-
volt signals are connected to terminals 2 & 3, milliamp
signals are connected to 1 & 3. Carefully observe the
polarity of the connections.
Figure 16. Input 2 - DC Volt, mV & mA Connections
Universal / Auxiliary Input 2 Connections –
Potentiometer
The optional auxiliary or 2nd universal input, the termi-
nals detailed below can be used to connect a feedback
potentiometer. Minimum potentiometer resistance is
≥
100 Ω .
Figure 17. Input 2 - Potentiometer Connections