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3.2.2 Field Wiring Instructions
Typical US field installation would find a 6 ft (2 m) AC cord wired and two (2) 1 ft (30 cm) AC receptacles (
On/Off
mode)
or two (2) 10 ft (3 m) pump drive cables (
Proportional
mode) installed. A BNC receptacle would be installed for the ORP
probe.
Connect the two (2) pumps appropriately. Install the probe, run the cable back to the controller and attach to BNC
receptacle. If the probe is farther than 25 ft (7.6 m) from the controller, a preamp may be desirable to reduce noise effects.
If this is the case, use +5V/-5V from control box TB4 Pin 9-10 for your preamplifier. Current draw must not be greater
than 10 mA.
If a flow meter and/or low-level tank switch is available, run wires to the controller entering through one of the spare cable
ports. Remove the appropriate jumper(s) and attach the external wires. Polarity does not matter. Wire size #20-22 is
adequate.
Alarm relays 1 and 2 are provided to signal an out of tolerance condition externally. These are Form C contacts, providing
a common, a normally open, and a normally closed connection. These terminals provide power output.
A solenoid drive relay (Form C contacts, providing a common, a normally open and a normally closed connection) is
provided that can be connected to drain a tank when the ORP is within programmed limits. A delay can be programmed
after initially entering this programmed zone, to allow conditions to settle within the tank. The duration of solenoid
On
time is also separately programmable. Wire size #16-18 is recommended. These terminals provide output power (main
voltage).
The optional 4-20 mA PCB provides a fully programmable 4-20 mA output based on the ORP readings. The optional PCB
plugs into the back of the computer PC board, as shown in Figure 6.
Figure 6: Circuit Board
