Thermo Scientific AquaSensors
™
AnalogPlus
™
Differential pH Sensor User Guide
13
3.3.
Wiring Overview
There are two different methods for electrical connection between the sensor and a pH controller: either direct
or through a junction box. For ease of maintenance it is recommended that any cable run over 30 feet employ
an indirect connection with a junction box and an extension cable.
3.1.1. Direct Connection
1.
Insert the sensor cable through a watertight cord grip or conduit into the AV88 or P99 Controller. It is
recommended that conduit holes on the bottom side of the controller be used for this purpose.
2.
Connect the sensor wires to the controller terminal block as outlined in the controller manual.
3.1.2. Indirect Connection (Using a Junction Box)
1.
Insert the sensor cable and the interconnect cable through a watertight cord grip or conduit into the
junction box that has a terminal strip designed to make the proper connections.
2.
Connect both the sensor cable wires and the interconnect wires to the terminal strip.
3.
Insert the interconnect cable through a watertight cord grip or conduit into the controller.
4.
Connect the sensor wires to the controller terminal block as outlined in the controller manual.
Be sure that the wire colors of the sensor cable match those of the interconnect cable on
either side of the terminal strip.
Route the interconnect cable through grounded metal conduit to minimize electrical noise
that may interfere with the sensor signal.
