Liquitron DC4500 Terminal Strip Layout

To access the wiring connections inside of the conductivity controller:

  1. Disconnect the unit from electrical power.
  2. Remove the four (4) screws and the junction box cover on the lower half of the unit.
  3. Consult the specific instructions below for the connections required.

AC  Power Input

Hot:        TB2-1
Neutral: TB1-4
Ground: TB4-4

Bleed Blowdown Control Relay Output

Hot (N.O.):   TB5-1
Hot (N.C.):   TB5-2
Neutral:        TB1-3
Ground:        TB4-3

Feed Output

On/Off

Hot:        TB6-1
Neutral: TB1-2
Ground: TB4-2

External Trigger

High:  TB9-3
Low:   TB9-4

Alarm Output

Hot:         TB6-2
Neutral:  TB1-1
Ground:  TB4-1

4-20 mAmp Output

( + )  TB9-1

(  – )  TB9-2

Biocide #1 Pump Output

On/Off

Hot:        TB6-3
Neutral: TB2-4
Ground: TB3-4

External Trigger

High:  TB8-1
Low:   TB8-2

Biocide #2 Pump Output

On/Off

Hot:       TB6-4
Neutral: TB2-3
Ground: TB3-3

External Trigger

High:  TB8-3
Low:    TB8-4

Flowmeter Input

The inputs are reversible when the flowmeter connection is a relay and has no polarity

TB10-1
TB10-2

Flow Switch Input

This input can be used to connect a flow switch or other device providing a switch closure  output.  If a device such as this is connected to the DC4500, it will serve to disable the controller outputs when this switch is in the “OPEN” position. This function can be used as a safety override to prevent controller/pump operation during loss of flow.

The inputs are reversible since the flow switch connection has no polarity.

TB10-3
TB10-4

Thermistor Probe Outlet (Hardware Only)

Run the thermistor probe wiring through the PG9 connector on the right side of the DC4500 controller junction box keeping the wires away from any 115/230 VAC cables that may cause electrical interference.

Signal Output: TB11-1
Signal Return: TB11-2

Conductivity Probe (Hardware Only)

Run the conductivity probe wiring through the PG9 connector on the right side of the DC4500 controller junction box keeping the wires away from any 115/230 VAC cables that may cause electrical interference.

Signal Output: TB11-3
Signal Return: TB11-4

Bottom of Controller
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On Off Output Control
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external pulse output control
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Operating the Controller