Minco
Tel: 763. 571.3121 • Fax: 763. 571.0927 • www.minco.com
4
Installation
Installation of the TT859 consists of mounting the transmitter to a wall and connecting it to
power. The housing is mounted using two countersink screws to secure the base plate to a
wall. Access the mounting holes by separating the plastic base plate from the cover. Then
secure the base plate to the wall, long edge to the vertical (observing the directional arrow
marked on the base plate). Power and RTD wires are connected to the transmitter by 4 screw
terminals located near the edge of the circuit board (Figure 1). The transmitter’s power and
RTD connections are designed for non-polar hook-up, so polarity is not important. If
calibration is necessary, set dip-switches before assembling housing (See
Transmitter Ranging
section).
Connect a DC source, not exceeding 35 VDC, to the “PWR” terminals as shown below (Figure
1).
Wiring Diagram
Figure 1
Power Supply
DC power supply requirements are determined by the T
T859’s minimum voltage requirement
and voltage drop across the load resistor and installation lead wires.
Example: The transmitter requires 9.4 Volts minimum. A typical 250 ohm load resistor drops 5.0
Volts @ 20 mA. Allowing a margin of 0.5 Volts for the supply permits 25 ohms of lead wire
resistance for remote installation. Totaling these, we get a minimum power supply requirement
of 14.9 VDC.
Using a 24 VDC power supply will take care of nearly all installations, but the TT859 will operate
at voltages up to 35 VDC.
