SMY133-SMY134-SMP133 Operating Manual
6.1.2 Digital Input (DI) Connection
The input supposes a voltage signal of appropriate magnitude is connected (see technical
specifications). The signal polarity for the „V“ and the „W“ models must be kept according the table
above. For the RR/RI/II models, it is free.
If the voltage exceeds declared level, the input is activated (=value 1).
Usual 12 or 24 V DC/AC signals can be connected directly. If you need to connect a voltage signal of
magnitude exceeding maximum digital input voltage, external limiting resistor of appropriate rating
must be used.
Any of the
„
V”-,
„
W“- ,
„
AA”- and
„
AT”-type digital inputs can be used as output too. When
used as input there must not be set output function on the same terminal. Furthermore,
proper polarity of signal terminal and appropriate common terminal must be kept.
The digital inputs are insulated from instrument internal circuitry.
For the „RR / RI / II“ models they are insulated from outputs too. For other models, each output pair of
inputs/outputs has common pole and the pairs are insulated mutually.
6.1.3 Analog Inputs Connection
If residual currents are not measured, the residual current inputs can be optionally used as 0-20mA
DC (or 4-20mA DC ) current loop analog inputs.
Check if the signal source is capable to work with the impedance of the input defined in the technical
specifications.
Connect positive signal (+) to the
IΔ11
/
IΔ21
terminal and negative signal (-) to the
IΔ12
/
IΔ22
.
Then set the input parameters – see the chapter
I/O Setup
below.
The residual current inputs and external temperature input are not insulated neither from
instrument internal circuitry nor mutually ! The terminals IΔ12 and IΔ22 (or IΔ12 and T- for
the AT-model) are connected internally, do not connect signals of different potential to them !
Maximum length of the cable is 3 meters. Otherwise, immunity against electromagnetic
disturbances can be affected negative !
As soon an analog input (AI) mode is activated in the I/O block setup (see below), residual
current monitoring on appropriate input is suppressed and appropriate I
Δ
value is no longer
available !
6.1.4 External Pt100 Temperature Sensor Connection
With the „AT“ model, an external temperature
T
E
can be measured. Corresponding input of this model
is designed for connection to a Pt100 resistive temperature sensor.
Connect the sensor to the terminals No. 45 (
T+
) and 46 (
T-
). As the sensor is connected with two
wires only, note that the sensor cable loop impedance must be as low as possible (each 0.39 Ohms
means additional measurement error of 1 ºC).
If any signal is connected to the IΔ11 - IΔ12 inputs too, note that IΔ12 terminal is connected
with the T- terminal internally. So mutually insulated signals or signals with the same
common pole potential can be connected only !
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