NOVUS TxBlock-USB Transmitter - Manual (Page 3)

TxBlock-USB
NOVUS AUTOMATION 3/4
ELECTRICAL CONNECTIONS
The figures below show the electrical connections required. The
terminals 3, 4, 5 and 6 are dedicated to the sensor connection.
LOAD represents the 4-20 mA current measuring device (indicator,
controller, recorder, etc.).
PT100 2-WIRES
Note: When the Pt100 2-wires the terminals 3 and 4 must be
interconnected, according to the figure below.
The Pt100 wire length should be less than 30 cm to maintain the
measurement error within specifications (electrical resistance).
Fig. 5 – Transmitter electrical connections (Pt100 2-wires)
PT100 3-WIRES
Fig. 6 – Transmitter electrical connections (Pt100 3-wires)
PT100 4-WIRES
Fig. 7 – Transmitter electrical connections (Pt100 4-wires)
Pt100 / Pt1000 3 and 4 wires: For appropriate cable resistance
compensation they should be equal for all legs. Maximum wire
resistance is 25 Ω per wire leg. Usage of a 3 or 4 wire with conductors
of equal length and gauge is recommended.
THERMOCOUPLES
Fig. 8 – Transmitter electrical connections (Thermocouple)
VOLTAGE (0-50 mV)
Fig. 9 – Transmitter electrical connections (0-50 mV)
OPERATION
The sensor offset can be changed through the TxConfig II software.
The USB cable may be connected to the transmitter without causing
any measurement errors. See item Zero Correction in the chapter
CONFIGURATION of this manual.
The uer must choose the most suitable sensor and range to the
process. The chosen range must not exceed the maximum range of
measurement defined for the sensor and should not be smaller than
the minimum range for the same sensor.
It is important to note that the transmitter accuracy is based on the
maximum range of the sensor used, even when a narrower range is
programmed. Example:
• The sensor Pt100 has a max. range of -200 to +650 °C and
accuracy of 0.12 %, thus we will have an error up to 1.7 °C
(0.2 % of 850 °C).
• This error may be present even when a narrower range is
configured for the sensor. (For example: 0 to 100 °C.)
Note: When measurements are made at the transmitter, see if the
Pt100 excitation current required by the calibrator is compatible with
the Pt100 excitation current used in the transmitter: 0.8 mA.