Convergent Water Controls DIGICHEM Plus + Instruction Manual

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Instruction Manual

Instruction Manual for

Water Treatment Controller

Model: DIGICHEM

Plus

(All software versions to 0.91)

Fill in serial number here

Refer to back page

Supplied by:

Convergent Water Controls Pty Ltd

2/4 Huntley Street, PO Box 7058 Alexandria NSW 2015

t: (02) 9698 3131 w: cwc.com.au f: (02) 9698 3210 e: support@cwc.com.au

M1 ver 4.0

Manufacturer:

Convergent Water Controls Pty Ltd, Sydney Australia.

Note:

On-going product development at Convergent Water Controls may lead

to changes in the specifications of this product.

Warranty:

This product is guaranteed for a period of 12 months from installation

date or 18 months from Invoice date (whichever occurs first). The warranty applies to manufacturing or component defects which may cause the unit to malfunction under specified conditions. The guarantee does not cover damage due to abuse, tampering or improper installation.

Disclaimer:

Convergent Water Controls will not be held liable for any consequential

damage or loss arising resulting from product malfunction.

TTaabbllee ooff CCoonntteennttss

Introduction...........................................................................................................................5

2. Installation ............................................................................................................................6

2.1 Electrical Wiring...........................................................................................................................6

2.2 Conductivity Probe Installation & Maintenance...............................................................................8

3. Controller Functionality.........................................................................................................9

3.1 Menu Logic..................................................................................................................................9

3.2 Pushbuttons .............................................................................................................................. 10

3.3 Controller Display Information .................................................................................................... 11

3.4 Comms Port............................................................................................................................... 11

4. Commissioning.....................................................................................................................11

4.1 Start-Up .................................................................................................................................... 12

4.1.1 Start-Up Delay ...............................................................................................................................13

4.2 Setting Time & Date................................................................................................................... 14

4.3 Calibration................................................................................................................................. 14

4.3.1 Conductivity (TDS / µS) Calibration..................................................................................................15

4.3 2 ORP mV Calibration........................................................................................................................18

4.3 3 pH Calibration................................................................................................................................22

4.4 Testing Relay Outputs................................................................................................................ 24

4.5 Manual Dose.............................................................................................................................. 26

4.6 View Settings............................................................................................................................. 29

4.7 Factory Settings......................................................................................................................... 30

5. Programming Setup Menu...................................................................................................31

5.1 µS/TDS Setup............................................................................................................................ 31

5.1 1 Set Conductivity Units.....................................................................................................................32

5.1.2 Set Bleed Setpoint..........................................................................................................................32

5.1.3 Set Conductivity Hysteresis .............................................................................................................33

5.1.4 Set Conductivity Bleed Cycle............................................................................................................34

5.2 ORP Setup................................................................................................................................. 35

5.2.1 Enable / Disable ORP Control ..........................................................................................................36

5.2 2 Select ORP Operation .....................................................................................................................36

5.2.3 Set ORP Setpoint............................................................................................................................37

5.3 pH Setup................................................................................................................................... 37

5.3.1 Enable / Disable pH Control.............................................................................................................38

5.3.2 Select pH Operation........................................................................................................................38

5.3.3 Set pH Setpoint..............................................................................................................................39

5.4 pH and ORP Control Method Setup.............................................................................................. 39

5.4.1 Setting the Control Method .............................................................................................................40

5.4 2 On/Off Control...............................................................................................................................40

5.4.3 Proportional Control........................................................................................................................43

5.4.4 Explanation of pH Control Methods..................................................................................................44

5.4.5 Explanation of ORP Control Methods................................................................................................45

5.5 Alarm Parameters ...................................................................................................................... 48

5.5.1 Conductivity Level Alarms ...............................................................................................................48

5.5.2 ORP Level Alarms...........................................................................................................................49

5.5.3 pH Level Alarms.............................................................................................................................50

5.5.4 No Flow Alarm ...............................................................................................................................52

5.5.5 Delay On Alarm..............................................................................................................................

5.5.6 Bleed Timer Alarm..........................................................................................................................53

5.5.7 ORP Dose Timer Alarm ...................................................................................................................54

5.5.8 pH Dose Timer Alarm .....................................................................................................................55

5.5.9 Timer Alarm Hysteresis (Software ver 0.91 & later)...........................................................................

5.5.10 Alarm Override (Software ver 0.80 & later).....................................................................................56

5.6 Inhibitor & Dispersant Setup....................................................................................................... 57

5.6.1 Dose on Bleed Mode.......................................................................................................................58

5.6.2 After Bleed Mode............................................................................................................................61

5.6.3 Twenty Four Hour Per Day (24hr/day) Cycle.....................................................................................62

5.6.4 Make-Up Water Pulses.................................................................................................................... 63

5.6.5 Bleed Water Pulses.........................................................................................................................65

5.7 Biocide Setup............................................................................................................................. 65

5.8 Pre-Bleed Setpoint ..................................................................................................................... 71

5.9 Bleed Lock-out Setpoint.............................................................................................................. 71

5.10 Condenser Pump Timer ............................................................................................................ 72

5.11 Flow Switch ............................................................................................................................. 74

5.12 Advanced Setup Menu.............................................................................................................. 76

5.12.1 Data Logging ...............................................................................................................................77

5.12.2 Disinfection..................................................................................................................................79

5.12.3 Extra Inhibitor Dose......................................................................................................................81

5.12.4 Water Volume Counters ................................................................................................................82

5.12.5 Cycles of Concentration.................................................................................................................84

5.12.6 Password Setup............................................................................................................................85

5.12.7 Controller Name........................................................................................................................... 87

5.12.8 Site Name....................................................................................................................................87

5.12.9 Remote Communications...............................................................................................................88

5.12.10 LCD Contrast (Software ver 0.80 & later)......................................................................................89

6. Factory Settings...................................................................................................................90

7. Specifications.......................................................................................................................91

8. Maintenance Schedule.........................................................................................................92

9. Optional Extras ....................................................................................................................92

10. Service & Technical Support................................................................................................94

Page 5 of 95

1. Introduction

Primarily designed for cooling tower water treatment, the DIGICHEM Plus+ electronic controller incorporates the following key features:

• Conductivity bleed control

• pH Control

• ORP Control

• Dispersant pump dosing control

• Inhibitor pump dosing control

• Dual Biocide pump control (via 10 independent 28-day timer programs)

• On Board Data logging

• Tower circulating/condenser pump override facility with delay-off timer

• High and Low Conductivity, pH & ORP alarms with programmable trip delay

• Internet Connectivity

Page 6 of 95

2. Installation

Mount the DIGICHEM Plus+ on a flat vertical surface away from extreme heat, humidity or areas where temperature variations are extreme, ideally at eyelevel to allow good visibility of the LCD display. Also ensure that a 240VAC mains power point is located nearby. Please refer to the detailed installation instructions for the system you have ordered (supplied with system).

2.1 Electrical Wiring

CAUTION: If opening the controller, pull the lid away from the base slowly to

ensure you do not impose any strain on the interconnecting cable, which easily unplugs from the motherboard.

The diagrams below show the connections to the DIGICHEM Plus+ controller circuitry:

4567

89101112 13

14 151617

37 38 39 40

42 43

44 454647

48 49 505152 53

19 20

21 22

25 262728 29 30 31 32 33 34 35 36

Upper Terminals

Lower Terminals

Input Terminals

55 56

GSM/GPRS PORT

I/O PORT

PROCESSOR BOARD CONNECTOR

Output Fuse - 4A

Controller Fuse - 2A

Page 7 of 95

Terminal

Number

Description

ORP Probe Signal ( White )

ORP Probe Common ( Green )

Ground Probe

pH Probe Signal ( White )

pH Probe Common ( Green )

Conductivity Probe PR+ ( Red )

Conductivity Probe PR- ( Yellow )

Conductivity Probe CM+ ( Blue )

Conductivity Probe Screen ( Grey )

Flow Switch

Water Meter - Make Up

Water Meter - Bleed

Spare

Terminal

Number

Description

Common Earth

Condenser Pump Common

Condenser Pump N/O (Volt-Free)

Auxiliary Output Neutral

Dispersant Output Neutral

pH Output Neutral

Biocide B Output Neutral

Biocide A Output Neutral

Inhibitor C Output Neutral

Solenoid Output Neutral

Mains Output Neutral

Mains Supply Neutral

Mains Earth

Terminal

Number

Description

Common Earth

Alarm N/C (Volt-Free)

Alarm N/O (Volt-Free)

Alarm Common

Auxiliary Output Active (240VAC)

Dispersant Output Active (240VAC)

pH Output Active (240VAC)

Biocide B Output Active (240VAC)

Biocide A Output Active (240VAC)

Inhibitor C Output Active (240VAC)

Solenoid Output Active (240VAC)

Mains Output Active (240VAC)

Mains Supply Active (240VAC)

12345678 9 10 11 12 13 14 15 16 17 18

373839 40 41 42 43 44 45 46 474849 50 51 52 53 54

19 20

21 22

25 262728 29 30 31 32 33 34 35 36

Power Terminals

Input Terminals

Earth Terminals

Terminal

Number

Description

Mains Output Active (240VAC)

Mains Output Neutral

Fuses: Controller fuse: 2A/250VAC (M205, 20mm x 5mm diameter) Output fuse: 4A/250VAC (M205, 20mm x 5mm diameter)

Notes on Alarm Relay Contacts :

1. Alarm relay is energised (ie. 25 connected to 26) during normal operation of the unit.

2. Alarm relay de-energises (ie. 24 connected to 26) when an alarm condition is confirmed or when the unit loses power.

Notes on Flow Switch:

A flow switch with N/O or N/C volt-free contacts is required to be connected to terminals 10 & 11 (not polarity sensitive). The flow switch logic is programmable via the menu.

Notes on Water Meter Inputs:

Water meters with Volt-free pulse outputs (e.g. Reed switches) are required for Make-Up & Bleed water meter inputs. For Mag-flow water meters with opto-coupled outputs, use terminals 12 & 14 for the +, and terminals 13 & 15 for the – inputs from the water meter.

NOTE: Terminals 55 & 56 may be omitted.

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2.2 Conductivity Probe Installation & Maintenance

The probe is supplied screwed into a PVC Tee piece such that the electrode tips are submerged in the water flowing through the manifold in which the tee is usually fitted. The probe should be positioned with the black markers on the probe aligned with the black markers on the manifold Tee. This ensures that the 2 electrodes of the probe are positioned symmetrically with respect to the direction of water flow. See the photograph and diagrams below:

The probe’s electrodes should periodically be cleaned to maintain accurate TDS measurements. The frequency of cleaning required will vary from one application to another. In a new installation, it is recommended that the probe be cleaned after 2 weeks of service.

To clean the probe, first unplug the probe lead and unscrew the probe from the manifold. The probe can normally be cleaned using a cloth or paper towel. Occasionally the probe’s carbon electrodes may be coated with substances which requires more vigorous cleaning (this coating may not always be visible). To clean a coated electrode, use a fine grit abrasive, such as emery paper.

After cleaning, apply more Teflon

tape to the probe thread and screw back into the manifold. The controller should always be calibrated after probe cleaning.

DIRECTION

OF FLOW

Page 9 of 95

3. Controller Functionality

3.1 Menu Logic

The DIGICHEM Plus+ has an advanced but very user-friendly menu system:

• The menu structure is circular

• The relevant menu item, or programmed value flashes on the display, and

is shown as bold letters or numbers when explained in this instruction manual.

• Up & Down arrow pushbuttons allow you to scroll through the menu items and to increase/decrease programmed settings

• The MAIN MENU expands to several levels of SUB MENUS when pressing ENTER on various menu items

• The BACK pushbutton can be pressed at any time to exit from a current menu to a previous menu screen, or to not save any edited settings

• The LCD is backlit

The MAIN MENU of the controller is illustrated as follows: (Software ver 0.80 & later)

Main Menu

1245 TDS [ 750]BLEED 490 mV [ 500] DOSE

7.67pH [ 7.50] DOSE

INHB DISP

► SETUP MENU

TEST OUTPUTS MANUAL DOSE

► CALIBRATION

ALARM PARAMETERS ALARM OVERRIDE

X 3

Press to access menu item

Press to exit

Hold

► TIME & DATE

FACTORY SETTINGS SETUP MENU

X 2

Note: If password protection is enabled, the controller will ask you to enter

your password before allowing you to enter this menu.

Page 10 of 95

3.2 Pushbuttons

The DIGICHEM Plus+ has 4 pushbuttons each of which have dual functions:

1. Scroll UP (Time & Date)

2. Scroll DOWN (Main Menu)

3. ENTER (Reset)

4. BACK (View Settings)

• The Scroll UP

and DOWN pushbuttons allows you to scroll in both directions in the circular menus. Once a menu item has been selected and there is a value to program, the Scroll pushbuttons allow you to increase or decrease the number programmed.

• The ENTER

pushbutton allows you to enter a part of the program that you have selected. It also accepts any numbers programmed with the Scroll pushbuttons.

• The BACK

pushbutton allows you to exit from any menu, as well as to

exit from any screen without saving values, should you have changed any values without pushing the ENTER pushbutton.

• If the Scroll UP (Time & Date) pushbutton is pressed momentarily in NORMAL MODE (explained in section 4.1), the time and date is displayed. To revert back to NORMAL MODE, press the pushbutton momentarily again. The time and date is displayed as follows:

alternates with

1245 TDS [ 750]BLEED 490 mV [ 500] DOSE

7.67pH [ 7.50] DOSE 7 Jul 2008

1245 TDS [ 750]BLEED 490 mV [ 500] DOSE

7.67pH [ 7.50] DOSE Mon 14:47-53 Week1

NOTE: The Time & Date is programmable, but the Week No is automatically set. Hence, if you have multiple controllers in the field, the Week No will be the same on all (assuming the Time & Date are programmed correctly).

• To get into the menus of the DIGICHEM Plus+, hold down the Scroll DOWN (Main Menu) pushbutton. The display will count down until you access the menus. If password protection is enabled, the controller will ask you to enter your password before allowing you to enter this menu.

• If you wish to cancel an alarm or any timers activated, press and hold the ENTER (Reset) pushbutton until the display says:

Resetting…

Page 11 of 95

3.3 Controller Display Information

Notes: (v0.91 or later)

• If a pulse from a make-up water meter is received, a ‘+’ will be displayed momentarily

• If a pulse from a bleed water meter is received, a ‘-’ will be displayed momentarily

3.4 Comms Port

There is a Comms port on the front panel of the controller next to the LCD. This is used to download data from the controller, and can also used to upload new software versions should they be required. The data is downloaded via the Comms port on the front panel of the controller. An optional cable is required; P/N SP-XP2-COMCABLE-1, to perform a direct download to a pc or laptop via the serial port.

However, some computers or laptops do not have a serial port, so a USB to serial adapter will be required. These can be purchased from any electronics store, or through CWC. Our part number: HOBO CABLE-USB-232. The brand “Keyspan” is recommended.

4. Commissioning

CAUTION: Refer to previous section before reading this section

Page 12 of 95

4.1 Start-Up

Connect Power to the controller after installation. After a start-up sequence, the controller automatically goes into NORMAL MODE. The display should read the measured conductivity as well as the conductivity Setpoint within square brackets (which alternates with the temperature as measured by the conductivity probe). Also displayed will be the measured pH, pH Setpoint within square brackets, measured ORP value, and the ORP Setpoint within square brackets.

Depending on the measured values, the controller may also display control functions of those illustrated in Section 3.3 for Controller Output Indication. An example of a start up screen is shown below:

Other information that you may see on the display, which alternates with the display above:

• When an alarm is reported, the actual alarm message will be periodically displayed in the specific area on the main screen, for that alarm. Please see the example below:

• When a flow switch is connected to the controller, each output is suspended when there is no flow past the flow switch. The outputs that would be suspended are only those that are selected via the Flow Switch Menu.

1245 TDS [ 750]pause 200 mV [ 500]DOSE

9.17 pH [ 7.50]DOSE NO FLOW

Example: No Flow Condition for Flow Switch Enabled on Bleed

Page 13 of 95

4.1.1 Start-Up Delay

Main Menu > SETUP MENU > GENERAL SETUP > START-UP DELAY

The Start-Up Delay feature is used to delay the operation of all control functions of the DIGICHEM Plus+ Controller upon initial power up.

This could be used if it was necessary for the system water to circulate adequately, for example to sufficiently mix chemicals in the water before controlling the pH, ORP or conductivity. This would also ensure the readings of these variables to first stabilise before commencing control.

The example below illustrates setting the Start-Up Delay to 6 minutes (or 360 seconds).

Example: Increasing the Start-Up Delay from 0 seconds to 360 seconds

► START-UP DELAY

INHIBITOR SETUP DISPERSANT SETUP

<START-UP DELAY>

COUNT-DOWN: 0000s

<START-UP DELAY>

COUNT-DOWN: 0300s

<START-UP DELAY>

COUNT-DOWN: 0300s

<START-UP DELAY>

COUNT-DOWN: 0360s

NOTE: The Start-Up delay will also take effect upon resumption of flow.

Page 14 of 95

4.2 Setting Time & Date

Main Menu > TIME & DATE

NOTE: The Week Number will be automatically set

4.3 Calibration

Main Menu > CALIBRATION

The Calibration menu has the following displays:

Calibration Menu

► CALIBRATE μ S/TDS

CALIBRATE ORP CALIBRATE pH

► CALIBRATE pH

CALIBRATE μ S/TDS CALIBRATE ORP

X 2

► CALIBRATION

ALARM PARAMETERS TIME & DATE

Press to access menu item

Press to return to main menu

X 2

Page 15 of 95

4.3.1 Conductivity (TDS / µS) Calibration

Main Menu > CALIBRATION > CALIBRATE µs/TDS

IMPORTANT: Select the display in either µS or TDS before proceeding.

(Refer section 5.1.1)

Calibrating the TDS SLOPE

Main Menu > CALIBRATION > CALIBRATE µs/TDS > SLOPE CAL µS/TDS

Take a sample of water from the sample valve on the manifold and measure the conductivity with a calibrated hand-held conductivity meter. Alternatively, insert the Conductivity probe in a buffer solution of known conductivity. Should the conductivity readout on the display differ from the sample taken, calibrate the controller as follows:

Adjust the current reading via the Calibration Menu to the desired reading.

Please see the example on the following page:

Page 16 of 95

Calibrating the µS/TDS ZERO

Main Menu > CALIBRATION > ZERO CAL µS/TDS

The zero is factory set so should not require calibration. However, if the display reads above zero with the conductivity probe disconnected, or with the probe dry, recalibrate the zero as follows:

1. Remove the probe from the manifold.

2. Dry the electrodes of the probe, so that there is zero (or minimal) conductivity between the electrodes.

3. Wait until the reading on the LCD is stable. If the reading does not settle to exactly 0, wait until it does not drop any further.

4. Go to the Calibrate Menu and set the Zero Calibration (see next page).

5. Screw the probe back into the manifold.

6. Perform the SLOPE calibration again.

Page 17 of 95

Alternative zero calibration procedure:

1. Disconnect the cable from the back of the probe.

2. Wait until the reading on the LCD is stable. If the reading does not settle to exactly 0, wait until it does not drop any further.

3. Go to the Calibrate Menu and set the Zero Calibration (see below).

4. Re-connect the cable to the probe securely.

5. Perform the SLOPE calibration again.

Calibrating the Zero for µS/TDS

► CALIBRATE μ S/TDS

CALIBRATE ORP CALIBRATE pH

► SLOPE CAL. μ S/TDS

ZERO CAL. μ S/TDS RESET μ S/TDS CAL.

Confirm? [NO ]

Calibrating...

► ZERO CAL. μ S/TDS

RESET μ S/TDS CAL. SLOPE CAL. μ S/TDS

Confirm? [YES]

Ensure cable is disconnected from probe, or the probe is completely dry before confirming

0 TDS [ 750]BLEED

495 mV [ 500] DOSE

7.52 pH [ 7.50] DOSE

To main screen

Resetting the TDS CALIBRATION

Main Menu > CALIBRATION > RESET µS/TDS CAL.

If you inadvertently calibrate the zero and/or slope to the incorrect values, and you cannot recover by repeating the normal calibration procedure, then you can reset the calibration and start again.

See diagram on the following page to reset the calibration:

Page 18 of 95

Resetting the µS/TDS Calibration

► CALIBRATE μ S/TDS

CALIBRATE ORP CALIBRATE pH

Reset? [NO ]

Reset? [YES]

X 2

► RESET μ S/TDS CAL.

SLOPE CAL. μ S/TDS ZERO CAL. μ S/TDS

► SLOPE CAL. μ S/TDS

ZERO CAL. μ S/TDS RESET μ S/TDS CAL.

0 TDS [ 750]BLEED

495 mV [ 500] DOSE

7.52 pH [ 7.50] DOSE

To main screen

Please Wait...

4.3 2 ORP mV Calibration

Main Menu > CALIBRATION > CALIBRATE ORP

NOTE: The DIGICHEM Plus+ is factory calibrated, so under normal

circumstances, calibration is not required. However, if you need to calibrate, or verify the reading in buffer solutions, proceed as follows:

Putting the controller into CALIBRATE mode automatically bypasses the solution ground probe. This enables you to use a mV simulator connected to the controller, or enables you to insert the ORP sensor in a buffer solution without the solution ground probe. This ensures you get an accurate reading on the controller. The ground probe is automatically enabled again when you exit ORP calibration.

Page 19 of 95

Calibrating the ORP SLOPE Main Menu > CALIBRATION > CALIBRATE ORP > SLOPE CAL. ORP

Before you proceed, set the mV simulator to the desired setting, or put the ORP sensor in the buffer solution.

IMPORTANT: Wait for the measured mV reading to stabilise before

proceeding.

Example: Calibrating the ORP Slope Value from 517mV to 475mV

► CALIBRATE ORP

CALIBRATE pH CALIBRATE μ S/TDS

► SLOPE CAL. ORP

ZERO CAL. ORP RESET ORP CAL.

517 mV

ENTER to Calibrate

BACK to Exit

ORP(mV) 0517

ORP(mV) 0417

ORP(mV) 0417

Calibrating...

ORP(mV) 0475

To Calibration screen –

display should now read

475 mV

Ensure ORP probe is in standard solution before proceeding. Do not immerse ground probe in solution.

Press when reading stabilises or

Press to return to the main screen once reading has been calibrated

Page 20 of 95

Calibrating the ORP ZERO Main Menu > CALIBRATION > CALIBRATE ORP > ZERO CAL. ORP

The zero is factory set so should not require calibration. However, if you want to set the zero, you will require a mV simulator with a 0mV or pH7 setting. Alternatively, you can short circuit the BNC input for this procedure.

Before you proceed, set the mV simulator to the zero setting (pH7 setting = 0mV)

IMPORTANT: Wait for the measured mV reading to stabilise before

proceeding. This reading should be very close to zero.

Page 21 of 95

Resetting the ORP CALIBRATION Main Menu > CALIBRATION > CALIBRATE ORP > RESET ORP CAL.

If you inadvertently calibrate the zero and/or slope to the incorrect values, and you cannot recover by repeating the normal calibration procedure, then you can reset the calibration and start again.

Resetting the ORP Calibration

► CALIBRATE ORP

CALIBRATE pH CALIBRATE μ S/TDS

Reset? [NO ]

Please Wait…

► RESET ORP CAL.

SLOPE CAL. ORP ZERO CAL. ORP

► SLOPE CAL. ORP

ZERO CAL. ORP RESET ORP CAL.

Reset? [YES]

X 2

850 TDS [ 750]BLEED 0 mV [ 500] DOSE

7.52 pH [ 7.50] DOSE

To main screen

Page 22 of 95

4.3 3 pH Calibration

Main Menu > CALIBRATION > CALIBRATE pH

The controller should automatically detect what buffer you are using. If not, the pH sensor may be faulty, or the controller might require a calibration reset only or possibly a factory and calibration reset.

NOTE: When calibrating, if the measured pH still deviates from that

of the buffer after pressing ENTER, then press the ENTER pushbutton again. This can be repeated until the reading becomes stable.

Please also note that if the ENTER button is not pressed after

approximately 4 minutes, the controller will time-out and enter the main screen. Therefore if a lengthy duration of calibration is required, please make sure the ENTER button is pressed at least once within a 4 minute time interval.

Please note that a buffer of 7 must always be used as one of the 2 buffers when calibrating pH. The second buffer can be either 4, 9 or 10.

If the calibration is not done successfully, the controller will momentarily display:

CALIBRATE INCOMPLETE

The controller will then exit to the main screen. If this is the case, then repeat the calibration procedure.

See an example of pH calibration on the following page:

Page 23 of 95

Main Menu > CALIBRATION > CALIBRATE pH > START CALIBRATION

► CALIBRATE pH

CALIBRATE μS/TDS CALIBRATE ORP

► START CALIBRATION

RESET pH CAL. .

To Main Screen

X 2

Disconnect pH Probe

Put probe in BUFFER

Then Press ENTER

Re-connect pH Probe

ENTER to Calibrate

6.50 pH

pH BUFFER [ 7 ]

ENTER to Calibrate.

With pH probe in a pH buffer of 7, wait for reading to settle and auto-detect. Do not immerse ground probe in pH buffer solution.

Now Insert pH probe in a pH buffer of 10 and wait for reading to settle and autodetect. Do not immerse ground probe in pH buffer solution.

CALIBRATE SUCCESSFUL

Example: Calibrating the pH for a reading of 6.5 pH in a 7 pH Buffer Solution, and a 9.92 pH

reading in a pH Buffer Solution of 10 pH

If the calibration is incomplete, redo this calibration procedure.

Note: Buffers of pH 4, or pH 9 can also be used.

850 TDS [ 750]BLEED

450 mV [ 500] DOSE

7.00 pH [ 7.50] DOSE

9.92 pH

pH BUFFER [10]

ENTER to Calibrate.

Calibrating...

7.00 pH

pH BUFFER [ 7 ]

ENTER to Calibrate.

10.00 pH

pH BUFFER [10]

ENTER to Calibrate.

Calibrating...

Follow the instructions on screen.

Press when the reading is stable

Press when calibration on 2 buffers is complete.

Page 24 of 95

Resetting the pH CALIBRATION Main Menu > CALIBRATION > CALIBRATE pH > RESET pH CAL.

NOTE: Once a pH Reset has been done, a pH calibration will be

required.

Resetting the pH Calibration

► CALIBRATE pH

CALIBRATE μ S/TDS CALIBRATE ORP

► START CALIBRATION

RESET pH CAL. .

► RESET pH CAL.

START CALIBRATION

Reset? [NO ]

Reset? [YES]

Please Wait…

To Main Screen

850 TDS [ 750]BLEED

450 mV [ 500] DOSE

7.00 pH [ 7.50] DOSE

4.4 Testing Relay Outputs

Main Menu > TEST OUTPUTS

Please see the following page for testing outputs:

Page 25 of 95

Test Outputs

► Test Bleed [NO)

► Test BIO ‘A’ [NO]

► Test INHIBTR [NO]

► Test ORP [NO]

► Test DISPER. [NO]

► Test pH [NO]

► Test ALARM [NO]

► Test Cond. PMP [NO]

► TEST OUTPUTS

MANUAL DOSE CALIBRATION

Press or to turn on

Press to move on to test the next output

Press to return to main menu at any time

If ORP is disabled, Test BIO ‘B’ will be displayed

► Test MODEM [NO]

This test is only displayed if remote comms is enabled in the advanced menu

► Test AUX. [NO]

(Ver. 0.83 and later)

Page 26 of 95

When any of the Outputs are activated, the Output relay switches, applying 240Vac power onto the output terminal, which activates the pump or solenoid valve wired to it. When the Alarm Output is activated, the relay de-energises, switching the Common from the Normally Open Contact to the Normally Closed contact of the Alarm relay.

If the MODEM is tested, the controller attempts to connect to the Internet if the MODEM is installed. If there is no modem installed, ‘GPRS Fault’ will be momentarily displayed at the bottom of the main screen, after the various MODEM status messages.

NOTES:

1. If any output is activated manually without reverting back to the deactivated state, the controller will automatically turn the output off 2 minutes after no pushbutton activity.

2. If you wish to drive an output for longer than 2 minutes, activate the MANUAL DOSE function within the MAIN MENU

3. The outputs should all switch on when tested, regardless of the flow condition.

4. Do not switch the Cond. PMP relay rapidly ON and OFF, if powering the condenser pump of the cooling tower.

4.5 Manual Dose

Main Menu > MANUAL DOSE

To perform an unattended slug dose of chemical, simply program the dose time (up to 99 minutes, in 1 minute increments) for any output.

NOTES:

• For any manual dose, the pump will dose even if there is no flow.

• The condenser pump will turn on automatically during any manual dose.

• To cancel a manual dose, press and hold the ENTER (Reset) pushbutton.

The Manual Dose Menu is shown on the following page:

Page 27 of 95

An example of Manual Dosing the Inhibitor is shown on the following page:

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Example: Manual Dosing the Inhibitor for 5 minutes

► Select O/P [BIO ‘A’ ]

► Select O/P [ORP ]

► Select O/P [INHIBTR]

► MANUAL DOSE

CALIBRATION ALARM PARAMETERS

► O/P on for: 00m

► O/P on for: 05m

X 5

Please Wait…1245 TDS [ 750]BLEED

490 mV [ 500] DOSE

7.67pH [ 7.50] DOSE INHIBTR – 05m

To main screen

NOTES: For any manual dose, the pump will dose even if there is no flow.

The condenser pump will turn on automatically during any manual dose. To cancel a manual dose, press and hold the ENTER (Reset) pushbutton. When a manual dose is active the main screen will display the output and the time left for the relevant output at the bottom of the display, eg. “INH – 01m” if the Inhibitor output will be active for 1 minute.

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4.6 View Settings

Main Menu > VIEW SETTINGS

To view all the settings you have programmed into the controller without going into the menus themselves, you can simply scroll up and down to view them all, as illustrated below:

Ho l d

Start Time: 00:00 Duration: 0250s

MakeUp Pulse/m³: 0002 Bleed Pulses/m³: 0002

1245 TDS [ 750]BLEED 490 mV [ 500] DOSE

7.67pH [ 7.50] DOSE

INHB DISP

ID: 0830-03534 Bootloader: Ver 2.00 SW S0200 Ver 0.54

Display: [TDS] Setpoint: 1000 Hysteresis: 03%

Bleed/Pause: 10/50s

Enable?: [YES] DOSE: [Oxidant ] Setpoint: 0500

Enable?: [YES] DOSE: [Acid ] Setpoint: 07.50

Control: [On/Off] Hysteresis: 05% Dose/Pause: 10/40s

Mode: [On Bleed ] ON Period: 0050s OFF Period: 0050s

Mode: [24hr/day ] ON Period: 0000s OFF Period: 0000s

Pre-Bleed: Setp

- 15%

Lock-Out: Setp + 20% Biocide dose + 000m

STARTUP DELAY: 0000s FLOW/SW: [NORMAL ]

LOG Every: 060m

T01 A 1-3- -M-W-F-

S13:30 D00h35 P00h10 L01h00

T10 ---- -------

S00:00 D00h00 P00h00 L00h00

Approx. Make-Up µS:

0200µS

[Westfield Tower 1 ]

[Westfield Bondi Jnct ]

Enable Modem:? [YES] GSM Logon Every: 015m

< µS/TDS ALARMS>

High Alarm: 0000 Low Alarm: 0000 Max Bleed: 120m

High Alarm: 0000 Low Alarm: 0000 Max Dose: 120m

High Alarm: 00.00 Low Alarm: 00.00 Max Dose: 120m

NO FLOW ALARM: [N] Trip Delay: 3600s Tmer Alarm Hyst: 3%

ORP (mV) Setpt: 0500 P01 ---- -------

00:00 D00h00

Control: [PROP] Prop. Band: 50% Cycle Time: 060s

Note: Timer Alarm Hysteresis displayed only for v0.91 or later.

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4.7 Factory Settings

Main Menu > FACTORY SETTINGS

CAUTION:

• Enter this part of the program ONLY if you wish to erase your program settings.

• The default settings (listed in Section 6 of this manual) most likely will not suit your application, so it will be necessary to reprogram the controller with your desired settings.

• This menu gives the option of resetting the calibration as well.

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5. Programming Setup Menu

Main Menu > SETUP MENU

IMPORTANT:

• Once settings are changed, it is necessary to exit the SETUP MENU in order to save your settings.

• Setup Menu Structure illustrated as follows:

Setup Menu

► μ S/TDS SETUP

ORP SETUP pH SETUP

► pH SETUP

GENERAL SETUP ADVANCED SETUP

X 2

► SETUP MENU

TEST OUTPUTS MANUAL DOSE

Press to access menu item

Press to return to main menu

X 3

5.1 µS/TDS Setup

Main Menu > SETUP MENU > µS/TDS SETUP

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5.1 1 Set Conductivity Units

Main Menu > SETUP MENU > µS/TDS SETUP > UNITS

Conductivity can be displayed in either:

• TDS (Total Dissolved Solids), or

• μS (Micro-siemens)

NOTE: The displayed units should be selected before performing any

calibration or programming of the unit.

5.1.2 Set Bleed Setpoint

Main Menu > SETUP MENU > µS/TDS SETUP > BLEED SETPOINT

Example: Decreasing Setpoint from 1000 TDS to 950 TDS

< μ S/TDS SETUP>

► BLEED SETPOINT

HYSTERESIS BLEED CYCLE

Setpoint: 1000

Setpoint: 0900

Setpoint: 0900

Setpoint: 0950

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The Bleed Setpoint is the desired conductivity value of the process (displayed in TDS or μS). When a solenoid valve is connected to the bleed output, the valve opens when the conductivity rises above the setpoint. When this occurs, the tower water is flushed to drain and fresh make-up water dilutes the system, thus lowering the conductivity of the tower water. The valve shuts when the conductivity drops to the Hysteresis value (explained in the next section). The cycle repeats.

5.1.3 Set Conductivity Hysteresis

Main Menu > SETUP MENU > µS/TDS SETUP > HYSTERESIS

Hysteresis is the deadband between the two conductivity points at which the solenoid valve opens and closes. The solenoid valve opens when the conductivity rises above the programmed setpoint and shuts when it drops to a level below the setpoint. This level is called Hysteresis and is a % of the setpoint.

NOTE: The maximum Hysteresis setting for the Conductivity, pH, and

ORP is 20%.

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5.1.4 Set Conductivity Bleed Cycle

Main Menu > SETUP MENU > µS/TDS SETUP > BLEED CYCLE

When the controller calls for bleed, the solenoid valve can be programmed to bleed continuously or on a cycle until it reaches the Conductivity Setpoint. To leave the Bleed Cycle in its disabled state, proceed to the next section. If you wish to program a bleed cycle, then proceed as follows:

The menu asks for a Bleed Time and a Pause Time to be programmed. The Pause Time follows the Bleed Time, and the cycle is repeated until the Setpoint minus Hysteresis is reached.

A bleed cycle can prevent excessive tower drainage in a very small system and allows the make-up to efficiently mix with the cooling tower water.

The ability to cycle is also useful because it prevents flooding by slowing down the bleed flow rate into a blocked drain. Another benefit is to force more return water back to the tower basin when chemical is dosed into the tower manifold during a long bleed duration.

An example of a Bleed / Pause setup is shown below. The solenoid bleeds 5 seconds during every 100 second cycle (ie 5 out of

100), which equates to a 5% bleed cycle.

Example: Programming a bleed cycle of 5 seconds bleed, followed by a pause of 95 seconds

< μ S/TDS SETUP>

► BLEED CYCLE

UNITS BLEED SETPOINT

Bleed/Pause: 00/00s

Bleed/Pause: 05/00s

Bleed/Pause: 05/00s

Bleed/Pause: 05/95s

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If you wish to have the control output continuously active during bleed (rather than cycling ON and OFF), simply set the Bleed/Pause times to 00/00s

NOTES: If the conductivity is greater than 25% above the programmed setpoint,

then the controller automatically adjusts the ON/OFF bleed cycle to bring it to setpoint more quickly.

If Inhibitor is set to “Dose on Bleed” mode, and an ON/OFF cycle for Inhibitor is programmed, then the Inhibitor ON/OFF cycle only occurs during the ON part of the Bleed Cycle. This means Inhibitor will only dose when the bleed valve is actually opened and passing water. During the OFF part of the Bleed Cycle, Inhibitor dosing is suspended.

5.2 ORP Setup

Main Menu > SETUP MENU > ORP SETUP

NOTE: For ORP Control Method Setup, please refer to section 5.4

In the example above, if ORP control method is set to Proportional Control, then instead of Hysteresis and Dose Cycle being displayed, Proportional Band and Control Cycle will be displayed as the last two menu options.

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5.2.1 Enable / Disable ORP Control

The DIGICHEM Plus+ can be programmed to have the ORP control function enabled, or disabled. See diagram below:

Important: High and Low ORP alarms are disabled when ORP control is

Disabled (for software versions 0.86 and older)

5.2 2 Select ORP Operation

Main Menu > SETUP MENU > ORP SETUP > OPERATION

The DIGICHEM Plus+ controller can dose either an oxidant (eg.) to increase the ORP, or a reductant (eg.) to decrease the ORP. Only one or the other can be selected. For cooling tower dosing applications, ORP control is always achieved by dosing Oxidant.

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5.2.3 Set ORP Setpoint

Main Menu > SETUP MENU > ORP SETUP > CONTROL SETPOINT

The ORP Setpoint is the desired ORP value of the process (displayed in mV).

Example: Decreasing ORP Setpoint from 500mV to 450mV

► CONTROL SETPOINT

CONTROL METHOD HYSTERESIS

ORP (mV)Setpt: 0500

ORP (mV)Setpt: 0400

ORP (mV)Setpt: 0400

ORP (mV)Setpt: 0450

5.3 pH Setup

Main Menu > SETUP MENU > pH SETUP NOTE: For pH Control Method Setup, please refer to section 5.4

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In the example above, if pH control method is set to On/Off Control, then instead of Proportional Band and Control Cycle being displayed, Hysteresis and Dose Cycle will be displayed as the last two menu options.

5.3.1 Enable / Disable pH Control

Main Menu > SETUP MENU > pH SETUP > ENABLE pH CONTROL? The DIGICHEM Plus+ can be programmed to have the pH control function

enabled, or disabled. See diagram below:

Important: High and Low pH alarms are disabled when ORP control is

Disabled (for software versions 0.86 and older)

5.3.2 Select pH Operation

Main Menu > SETUP MENU > pH SETUP > OPERATION

The DIGICHEM Plus+ controller can dose either an Acid (eg. Sulphuric Acid) to lower the pH, or a Base (eg. Sodium Hydroxide) to increase the pH. Only one or the other can be selected:

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5.3.3 Set pH Setpoint

Main Menu > SETUP MENU > pH SETUP > CONTROL SETPOINT The pH Setpoint is the desired pH value of the process:

Example: Decreasing setpoint from 7.50pH to 6.25pH

► CONTROL SETPOINT

CONTROL METHOD PROPORTIONAL BAND

pH Setpoint: 07.50

pH Setpoint: 06.50

pH Setpoint: 06.50

pH Setpoint: 06.25

5.4 pH and ORP Control Method Setup

Main Menu > SETUP MENU > ORP SETUP > CONTROL METHOD or: Main Menu > SETUP MENU > PH SETUP > CONTROL METHOD

The DIGICHEM Plus+ controls the pH and the ORP independently with On/Off or Proportional control methods.

These 2 methods of control will be discussed below, namely:

• ON/OFF control with programmed Dose Cycle (ie modulation), or

• PROPORTIONAL control via automatically varying the duty cycle

With ON/OFF control, the controller either turns the pump on continuously when correcting the pH/ORP or modulates the pump by turning the pump ON and OFF during the dosing period. The On period and Off periods are programmable.

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With proportional control, the dosing algorithm modulates the pump based on a percentage pH variation from the Setpoint. The further the pH / ORP is from the Setpoint, the shorter the OFF period is with respect to the ON period. The closer the pH/ORP is to the Setpoint, the longer the OFF period is with respect to the ON period. The control cycle and the proportional band are programmable.

5.4.1 Setting the Control Method

Set the control method as follows: Main Menu > SETUP MENU > ORP SETUP > CONTROL METHOD

Control: [On/Off]

Press after selecting control method

Control: [Prop. ]

► CONTROL METHOD

HYSTERESIS DOSE CYCLE

Example: Setting the ORP Control Method from On/Off to Proportional

5.4 2 On/Off Control

For On/Off Control, the menu structure will be different to that of Proportional Control. For the Control Method set to On/Off Control, the menu structure is shown below for the ORP setup:

Note: The same can be applied to the pH Setup menu.

► CONTROL METHOD

HYSTERESIS DOSE CYCLE

Now set the Hysteresis of the controller: NOTE: The maximum Hysteresis setting for the Conductivity, pH, and

ORP is 20%.

Main Menu > SETUP MENU > ORP SETUP > HYSTERESIS

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Example: Increasing the ORP Hysteresis from 5% to 10%

Hysteresis: 05%

► HYSTERESIS

DOSE CYCLE ENABLE CONTROL

Hysteresis: 10%

X 5

Tip: Set the Hysteresis to 1% if a dose cycle is required..

Now set the Dose Cycle of the controller:

Main Menu > SETUP MENU > ORP SETUP > DOSE CYCLE

When the controller calls for dosing, the pump(s) can be programmed to dose continuously or on a cycle until it reaches the pH and/or ORP Setpoints. A cycle is recommended to reduce overshoot, and to preserve the life of the pump(s).

The menu asks for a Dose Time and a Pause Time to be programmed. The Pause Time follows the Dose Time, and the cycle is repeated until the Setpoints plus/minus Hysteresis is reached. The diagram on the following page illustrates a dose cycle programmed for a 5 second dose followed by 10 second pause:

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Example: Programming an ORP Dose cycle to Dose for 5 seconds, followed by a pause of 10 seconds

Dose/Pause: 00/00s

► DOSE CYCLE

ENABLE ORP CONTROL? OPERATION

X 5

Dose/Pause: 05/00s

Dose/Pause: 05/00s

Dose/Pause: 05/10s

X 5

In the example above, the pump doses 5 seconds during every 15 second cycle (i.e. 5 out of 15 seconds), which equates to a 33% duty cycle.

The function of the dose cycle is to assist in reducing overshoot by achieving ORP (or pH) change more slowly. In a large system, there is often a lag after dosing until the ORP or pH sensor realises a change in actual value. The lag time estimated should be programmed as the Pause time.

Should the readout drift more than 25% away from the programmed Setpoint, the controller automatically doubles the Dose time and halves the Pause time to bring the ORP and/or pH within 25% of the Setpoint very quickly. As soon as the readout returns to within 25% of the Setpoint, normal pump duty cycle (ie. programmed Dose/Pause times) will resume. In the example above, the Dose and Pause times will temporarily be 5 seconds each, i.e. the pump(s) will dose for 5 seconds during every 15 second cycle, which equates to a 33% duty cycle.

If you wish to have the control output continuously active during dosing (rather than cycling ON and OFF), simply set the Dose/Pause times to 00/00s. However, it is recommended to then increase the Hysteresis to at least 5%.

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5.4.3 Proportional Control

For Proportional Control, the menu structure will be different to that of On/Off Control. For the Control Method set to Proportional Control, the menu structure is shown below for the pH setup:

Note: The same cam be applied to the ORP Setup menu.

Now set the Proportional Band of the Controller:

Main Menu >

SETUP MENU > pH SETUP > PROPORTIONAL BAND

Example: Increasing pH Proportional Band from 10% to 15%

Prop. Band: 10%

► PROPORTIONAL BAND

CONTROL CYCLE ENABLE PH CONTROL?

X 5

Prop. Band: 15%

Now set the Control Cycle of the Controller:

Main Menu > SETUP MENU > pH SETUP > CONTROL CYCLE

Please see the diagram below for pH Control Cycle Setup:

Example: Decreasing the pH Proportional Control Cycle time from 100s to 50s

Cycle Time: 100s

► CONTROL CYCLE

ENABLE pH CONTROL OPERATION

X 5

Cycle Time: 50s

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Whilst dosing, if the pH and/or ORP reading on the LCD changes very quickly, the Control Cycle will need to be as short as possible, eg 10 seconds. This will reduce overshoot, as the controller will be able to adjust its dose rate very quickly in responding to a rapidly changing pH and/or ORP.

Conversely, in a large system with a large volume of water, and a slow recirculation rate, the pH and/or ORP reading may take a long time to change after dosing occurs. In this case, it is better to have a longer Control Cycle, eg 100 seconds, to allow for the ORP reading to change, before further dosing takes place.

If unsure, set the control cycle to your best estimate of the time it takes for the water where the chemical is injected into, to get back to the pH and/or ORP sensors.

5.4.4 Explanation of pH Control Methods

The DIGICHEM Plus+ features 2 methods of pH control:

• ON/OFF control with programmed Dose Cycle (ie modulation), or

• PROPORTIONAL control via automatically varying duty cycle

On/Off pH Control Explanation:

If dosing acid, the pump will dose when the pH readout rises above the pH Setpoint. Dosing will stop once the readout drops below the pH SETPOINT minus a percentage. (This percentage is the Hysteresis value and is a percentage of the SETPOINT).

If dosing base, the pump will dose when the pH readout drops below the pH SETPOINT. Dosing will stop once the readout rises above the pH SETPOINT plus the Hysteresis percentage.

Hysteresis prevents rapid switching of the pump on and off when the system pH hovers around the Setpoint. Hysteresis is the difference between the two pH points at which the pump starts and the pump stops. Hysteresis is programmed as a percentage of the Setpoint, is only applicable to ON/OFF control, and is usually only required to be greater than 1% if no dose cycle is programmed.

For example, if the SETPOINT is 7.00pH and the Hysteresis value is 5%, then the calculated Hysteresis value is 0.35 pH.

If dosing acid, the pump will be activated when the pH rises above 7.00pH and will stop when the pH drops to 6.65 pH (ie. 7.00pH minus 0.35pH).

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If dosing base, the pump will be activated when the pH drops below

7.00pH and will stop when the pH rises above 7.35 pH (ie. 7.00pH plus

0.35pH).

Proportional pH Control Explanation:

With proportional control, the controller will always attempt to keep the pH as close as possible to the Setpoint. For proportional control to work, the controller requires the Setpoint as well as 2 other parameters to be programmed:

• The Proportional Band, and

• The Control Cycle

The Proportional Band, set as a percentage of the Setpoint, is the band in which proportional control takes place. For example if the Setpoint =

7.00 pH, and the Proportional band is 10%, then proportional control takes place between 7.00 pH and 7.70 pH (dosing acid) or between 7.00 pH and

6.30 pH (dosing base). Once the Setpoint is reached, the control output is OFF continuously.

Outside of the proportional band on the opposite end, the control output is ON continuously.

Proportional control, which takes place within the proportional band is explained as follows:

Assuming a pump is connected to the control output, the controller will modulate the power supply to the dosing pump proportionally. This modulation is an ON/OFF cycle (called the Control Cycle) where the ON/OFF ratio reduces the closer the pH is to the Setpoint (i.e. The ON time is much shorter than the OFF time). Conversely, if the pH starts drifting away from the Setpoint (but still within the proportional band), the ON time starts getting longer with respect to the OFF time.

NOTE: (v0.71 or later) If using the pH Dose Timer Alarm operating in

Proportional control, the timer will cancel if the measured pH reaches 97% of the pH Setpoint, rather than cancelling at the actual Setpoint itself.

5.4.5 Explanation of ORP Control Methods

The DIGICHEM Plus+ features 2 methods of ORP control:

• ON/OFF control with programmed Dose Cycle (ie modulation), or

• PROPORTIONAL control via automatically varying duty cycle

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On/Off ORP Control Explanation: If dosing oxidant, the pump will dose when the ORP readout drops below

the ORP SETPOINT . Dosing will stop once the readout rises above the ORP SETPOINT plus the Hysteresis percentage. (This percentage is the Hysteresis value and is a percentage of the SETPOINT). Cooling tower applications require dosing an Oxidant to increase the ORP.

If dosing reductant, the pump will dose when the ORP readout rises above the ORP SETPOINT . Dosing will stop once the readout drops below the ORP SETPOINT minus a percentage. (This percentage is the Hysteresis value and is a percentage of the SETPOINT).

Hysteresis prevents rapid switching of the pump on and off when the system ORP hovers around the Setpoint. Hysteresis is the difference between the two mV points at which the pump starts and the pump stops. Hysteresis is programmed as a percentage of the Setpoint, is only applicable to ON/OFF control, and is usually only required to be greater than 1% if no dose cycle is programmed.

For example, if the SETPOINT is 500 mV and the Hysteresis value is 5%, then the calculated Hysteresis value is 25 mV.

If dosing oxidant, the pump will be activated when the ORP drops below 500 mV and will stop when the ORP rises above 525 mV (i.e. 500 mV plus 25 mV).

If dosing reductant, the pump will be activated when the ORP rises above 500 mV and will stop when the ORP drops to 475 mV (i.e. 500 mV minus 25 mV).

Proportional ORP Control Explanation:

With proportional control, the controller will always attempt to keep the ORP as close as possible to the Setpoint. For proportional control to work, the controller requires the Setpoint as well as 2 other parameters to be programmed:

• The Proportional Band, and

• The Control Cycle

The Proportional Band, set as a percentage of the Setpoint, is the band in which proportional control takes place. For example if the Setpoint = 500 mV, and the Proportional band is 10%, then proportional control takes place between 500 mV and 550 mV (dosing reductant) or between 500 mV and 450 mV (dosing oxidant). Once the Setpoint is reached, the control output is OFF continuously.

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Outside of the proportional band on the opposite end, the control output is ON continuously.

Proportional control, which takes place within the proportional band is explained as follows:

Assuming a pump is connected to the control output, the controller will modulate the power supply to the dosing pump proportionally. This modulation is an ON/OFF cycle (called the Control Cycle) where the ON/OFF ratio reduces the closer the ORP is to the Setpoint (i.e. The ON time is much shorter than the OFF time). Conversely, if the ORP starts drifting away from the Setpoint (but still within the proportional band), the ON time starts getting longer with respect to the OFF time.

NOTE: (Software v0.71 or later) If using the ORP Dose Timer Alarm

operating in Proportional control, the timer will cancel if the measured ORP reaches 97% of the ORP Setpoint, rather than cancelled at the actual Setpoint itself.

The Control Cycle is the other parameter to be programmed. Whilst dosing, if the ORP reading on the LCD changes very quickly, the Control Cycle will need to be as short as possible, eg 10 seconds. This will reduce overshoot, as the controller will be able to adjust its dose rate very quickly in responding to a rapidly changing ORP.

Conversely, in a large system with a large volume of water, and a slow recirculation rate, the ORP reading may take a long time to change after dosing occurs. In this case, it is better to have a longer Control Cycle, eg 100 seconds, to allow for the ORP reading to change, before further dosing takes place.

If unsure, set the control cycle to your best estimate of the time it takes for the water where the chemical is injected into, to get back to the ORP sensor.

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5.5 Alarm Parameters

Main Menu > ALARM PARAMETERS

Alternative Menu

v0.91 or later

► μ S/TDS LEVEL ALRMS

ORP LEVEL ALARMS pH LEVEL ALARMS

► NO FLOW ALARM

DELAY ON ALARM BLEED TIMER ALARM

► ORP DOSE TIMER ALM

pH DOSE TIMER ALM μ S/TDS LEVEL ALRMS

X 3

► ALARM PARAMETERS

TIME & DATE FACTORY SETTINGS

Press to access menu item

Press to return to main menu

X 2

► ORP DOSE TIMER ALM

pH DOSE TIMER ALM TIMER ALM HYSTERESIS

The controller has 8 programmable alarm functions as outlined above. If any of the alarms are activated and confirmed, the common alarm contact switches, and the Alarm message is displayed on the relevant position on the Main Menu of the LCD.

5.5.1 Conductivity Level Alarms

The High Conductivity Alarm is activated if the Conductivity rises above the programmed setting, and automatically resets if the Conductivity drops below the programmed setting again.

The Low Conductivity Alarm is activated if the Conductivity drops below the programmed setting, and automatically resets if the Conductivity rises above the programmed setting again.

Please see the following page for an example of how to set the High and Low alarms for conductivity:

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Main Menu > ALARM PARAMETERS >µS/TDS LEVEL ALRMS

Example: Setting a High Alarm of 1200 TDS and a Low Alarm of 450 TDS

<ALARM PARAMETERS> ► μ S/TDS LEVEL ALRMS

ORP LEVEL ALARMS pH LEVEL ALARMS

< μ S/TDS LEVEL ALRMS>

High Alarm: 0000 Low Alarm: 0000

< μ S/TDS LEVEL ALRMS>

High Alarm: 1200 Low Alarm: 0000

< μ S/TDS LEVEL ALRMS>

High Alarm: 1200 Low Alarm: 0000

< μ S/TDS LEVEL ALRMS>

High Alarm: 1200 Low Alarm: 0000

< μ S/TDS LEVEL ALRMS>

High Alarm: 1200 Low Alarm: 0400

< μ S/TDS LEVEL ALRMS>

High Alarm: 1200 Low Alarm: 0400

< μ S/TDS LEVEL ALRMS>

High Alarm: 1200 Low Alarm: 0450

NOTE: Setting the High or Low Alarms to 0000 disables the Alarm.

5.5.2 ORP Level Alarms

The High ORP Alarm is activated if the ORP rises above the programmed setting, and automatically resets if the ORP drops below the programmed setting again. The Low ORP Alarm is activated if the ORP drops below the programmed setting, and automatically resets if the ORP rises above the programmed setting again.

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Main Menu > ALARM PARAMETERS > ORP LEVEL ALARMS

Example: Setting a High Alarm of 650mV and a Low Alarm of 350mV

► ORP LEVEL ALARMS

pH LEVEL ALARMS NO FLOW ALARM

High Alarm: 0000 Low Alarm: 0000

High Alarm: 0600 Low Alarm: 0000

High Alarm: 0600 Low Alarm: 0000

High Alarm: 0650 Low Alarm: 0000

High Alarm: 0650 Low Alarm: 0000

High Alarm: 0650 Low Alarm: 0300

High Alarm: 0650 Low Alarm: 0300

High Alarm: 0650 Low Alarm: 0350

NOTE: Setting the High or Low Alarms to 0000 disables the Alarm.

NOTES:

1. During Disinfection, the HIGH ORP alarm is ignored, until the mV drops below the HIGH ORP alarm value (if programmed). This enables you to have the Disinfection Setpoint higher than the HIGH ORP Alarm, without generating an alarm during Disinfection.

(Software v0.83 or later)

2. During No-Flow, the High and Low ORP alarms are disabled. However an alarm reported before a No-Flow condition is not affected and will remain in alarm during No-Flow, When flow returns, alarm is reset

(Software v0.91 or later)

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5.5.3 pH Level Alarms

The High pH Alarm is activated if the pH rises above the programmed setting, and automatically resets if the pH drops below the programmed setting again.

The Low pH Alarm is activated if the pH drops below the programmed setting, and automatically resets if the pH rises above the programmed setting again.

Main Menu > ALARM PARAMETERS >pH LEVEL ALARMS

Example: Setting a High Alarm of 9.5 pH and a Low Alarm of 5.5 pH

<ALARM PARAMETERS> ► pH LEVEL ALARMS

NO FLOW ALARM DELAY ON ALARM

High Alarm: 00.00 Low Alarm: 00.00

High Alarm: 09.00 Low Alarm: 00.00

High Alarm: 09.00 Low Alarm: 00.00

High Alarm: 09.50 Low Alarm: 00.00

High Alarm: 09.50 Low Alarm: 00.00

High Alarm: 09.50 Low Alarm: 05.00

High Alarm: 09.50 Low Alarm: 05.00

High Alarm: 09.50 Low Alarm: 05.50

NOTES:

1. Setting the High or Low

Alarms to 00.00 disables the Alarm.

(All Software versions)

2. During No-Flow, the High

and Low ORP alarms are disabled. However an alarm reported before a No-Flow condition is not affected and will remain in alarm during No-Flow, When flow returns, alarm is reset

(Software v0.91 or later)

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5.5.4 No Flow Alarm

Main Menu > ALARM PARAMETERS > NO FLOW ALARM

If the No Flow Alarm is enabled, the Alarm will activate when there is no flow detected by the optional flow switch. NOTE: A flow switch is included with all dosing systems incorporating a

DIGICHEM Plus+ Controller. If the No Flow Alarm is left disabled, then the Alarm is unaffected by a no-flow condition.

5.5.5 Delay On Alarm

Main Menu > ALARM PARAMETERS > DELAY ON ALARM

Example: Setting the Delay on Level Alarms to 2 minutes

<ALARM PARAMETERS> ► DELAY ON ALARM

BLEED TIMER ALARM ORP DOSE TIMER ALM

Trip Delay: 0008s

Trip Delay: 0108s

Trip Delay: 0108s

Trip Delay: 0120s

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When an alarm condition is detected, e.g. High Conductivity Alarm, the relay only trips immediately if the Trip Delay is set to 2 seconds. However, if alarms do not become immediately critical, it is better to program a delay on the alarm to prevent “nuisance trips”.

If a Trip Delay, e.g. 120s, is programmed, the alarm relay will only trip if the High Conductivity condition exists continuously for 120 seconds. However, if the Conductivity drops to below the High Conductivity Alarm level before the 120 seconds times out, the Alarm condition will reset.

NOTE: The minimum alarm trip delay able to be set is 2 seconds.

5.5.6 Bleed Timer Alarm

Main Menu > ALARM PARAMETERS > BLEED TIMER ALARM

<ALARM PARAMETERS> ► BLEED TIMER ALARM

ORP DOSE TIMER ALM pH DOSE TIMER ALM

Max Bleed: 0 00m

Max Bleed: 000m

Example: Leaving the Bleed Timer Alarm Disabled

The Bleed Timer Alarm is the maximum acceptable bleed time for the system to reach the Setpoint. This alarm is designed to protect the system from excessive bleeding in the event of a false reading from a faulty Conductivity probe, or if the controller itself is faulty.

To leave the alarm in its disabled state, the programmed setting is 000m. If the system Conductivity reaches the Setpoint within the programmed

time, the timer resets. However, if the timer times out before the Conductivity reaches the Setpoint, the bleed solenoid switches off and remains disabled until the unit is manually reset by holding down the Reset pushbutton.

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5.5.7 ORP Dose Timer Alarm

Main Menu > ALARM PARAMETERS > ORP DOSE TIMER ALM

Example: Setting a Maximum Continuous ORP Dose Time of 60 minutes

<ALARM PARAMETERS> ► ORP DOSE TIMER ALM

pH DOSE TIMER ALM μ S/TDS LEVEL ALRMS

Max Dose: 1 20m

Max Dose: 0 20m

Max Dose: 020m

Max Dose: 060m

The ORP Dose Timer Alarm is the maximum acceptable Dose time for the system to reach the ORP Setpoint (or 97% of the Setpoint, for software v0.71 or later). This alarm is designed to protect the system from excessive dosing in the event of a false reading from a faulty ORP probe, or if the controller itself is faulty.

To disable the ORP Dose Timer Alarm, program the timer setting to 000m. If the system ORP reaches the Setpoint within the programmed time, (or

97% of the Setpoint for software v0.71 or later), the timer resets. However, if the timer times out before the ORP reaches this level, the ORP Dose Timer Alarm is raised and the pump switches off and remains disabled until the unit is manually reset by holding down the Reset pushbutton.

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5.5.8 pH Dose Timer Alarm

Main Menu > ALARM PARAMETERS > pH DOSE TIMER ALM

Example: Disabling pH Dose Timer Alarm

► pH DOSE TIMER ALM

μ S/TDS LEVEL ALRMS ORP LEVEL ALARMS

Max Dose: 1 20m

Max Dose: 0 20m

Max Dose: 020m

Max Dose: 000m

The pH Dose Timer Alarm is the maximum acceptable Dose time for the system to reach the pH Setpoint (or 97% of the Setpoint for software v0.71 or later). This alarm is designed to protect the system from excessive dosing in the event of a false reading from a faulty pH probe, or if the controller itself is faulty.

To disable the pH Dose Timer Alarm, program the timer setting to 000m. If the system pH reaches the Setpoint within the programmed time (or

97% of the Setpoint for software v0.71 or later), the timer resets. However, if the timer times out before the pH reaches this level, the pH Dose Timer Alarm is raised and the pH Pump switches off and remains disabled until the unit is manually reset by holding down the Reset pushbutton.

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5.5.9 Timer Alarm Hysteresis (Software ver 0.91 & later)

Main Menu > ALARM PARAMETERS > TMR ALM HYSTERESIS

Setting the Timer Alarm Hysteresis to 5%

Hysteresis: 3%

X 2

<TMR ALM HYSTERESIS> Hysteresis: 5%

► TIMER ALM HYSTERESIS

μ S/TDS LEVEL ALRMS ORP LEVEL ALARMS

Sections 5.5.7 & 5.5.8 explain how the Timer Alarms reset themselves if the pH or ORP reaches 97% of the setpoint (ie. A Timer Alarm Hysteresis of 100–97= 3%). For DIGICHEM Plus+ controllers with a software version 0.91 or later, this percentage is programmable from 1 to 20%. For instance, if you are happy if the ORP reaches 90% of setpoint (eg. 450mV, if setpoint is 500mV), then set Timer Alarm Hysteresis to (100–90= 10%), so that the ORP Timer Alarm cancels if the ORP is above 450mV.

5.5.10 Alarm Override (Software ver 0.80 & later)

Main Menu > ALARM OVERRIDE

The DIGICHEM Plus+ has the feature to disable all alarms temporarily. This is useful, for example, if you are performing a tower clean, where the ORP, pH or Conductivity levels may rise or fall above or below preprogrammed alarm parameters.

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In this case you would not want the alarms to trigger, so therefore the alarm override feature locks out, or disables all alarms for a programmable time period (0 to 99 hours).

The Alarm Override is also logged as a percentage of the data logging interval in the controller’s data log. For example, if the data logging interval is 120 minutes and the alarm override was active for 60 minutes during this time, the log would display 50%.

5.6 Inhibitor & Dispersant Setup

Main Menu > SETUP MENU > GENERAL SETUP > INHIBITOR SETUP Main Menu > SETUP MENU > GENERAL SETUP > DISPERSANT SETUP

The above two features are identical, but work independently. There are 5 Possible Inhibitor/Dispersant Feed Pump Modes to select from:

• Dose on a Cycle when the controller is bleeding (Mode: On Bleed)

• Dose on a Cycle for the same bleed time, but delayed until bleed is

completed (Mode: After Bleed)

• Dose on a continuous Cycle (Mode: 24hr/day)

• Dose upon pulses received from a Make-up flow meter (Mode: MakeUp

Pulses)

• Dose upon pulses received from a Bleed flow meter (Mode: Bleed Pulses)

In the examples to follow, it may be necessary to change the current Inhibitor mode. The screens will vary according to if you are in the mode that requires a change, or you are changing to a new mode.

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Inhibitor Setup Menu

► INHIBITOR SETUP

DISPERSANT SETUP BIOCIDE TIMERS

Mode: [On Bleed ]

Mode: [MakeUp Pulses]

Press or to scroll through inhibitor modes

Press at any time to select mode

Mode: [Bleed Pulses ]

Mode:[24hr/day ]

Mode: [After Bleed ]

5.6.1 Dose on Bleed Mode

In this mode, the Inhibitor Pump doses during bleed, on a programmable ON/OFF time cycle when the measured Conductivity is greater than the Conductivity Setpoint, as long as the Bleed Cycle is set to ON/OFF = 00/00s, i.e. Bleed continuously.

RECOMMENDATION: If dosing Inhibitor on bleed when a bleed cycle is programmed, it is recommended to program a longer Bleed Cycle ON time than the complete Inhibitor Cycle. For example, program the bleed cycle to 50s ON/ 80s OFF, and the Inhibitor cycle to 2s ON/ 10s OFF (Hence, the 2/10s cycle only operates during the Bleed 50s ON time period).

The logic

is that if you change the bleed cycle, the Inhibitor dosage as a proportion of the time the bleed solenoid is actually bleeding, does not change.

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Example: Changing Inhibitor from “Bleed Pulses” mode to “On Bleed” mode -

Decreasing Inhibitor pump duty cycle from 50% to 30%

Mode: [On Bleed] ON Period: 0030s OFF Period: 0070s

Mode: [On Bleed]

Mode: [On Bleed] Change Mode? [NO ]

Mode: [On Bleed] ON Period: 0050s OFF Period: 0050s

Mode: [On Bleed] Change Mode? [YES]

Mode: [On Bleed] ON Period: 0050s OFF Period: 0050s

Mode: [On Bleed] ON Period: 0030s OFF Period: 0050s

Mode: [On Bleed] ON Period: 0030s OFF Period: 0050s

Mode: [On Bleed] ON Period: 0030s OFF Period: 0050s

► INHIBITOR SETUP

DISPERSANT SETUP BIOCIDE TIMERS

Mode: [Bleed Pulses]

In the previous example, some of the screens may not appear, if you are already in ‘On Bleed’ mode, and you enter to this menu again. See the example below:

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NOTE: For most applications, it is recommended to work on a 100

second cycle. For any of the % of Time modes, you can use the table on the follow page as a guide to set your Inhibitor or Dispersant pump duty cycle:

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Dosing Pump Turn-down required ON Period OFF Period

10% of maximum dose rate 0010s 0090s 20% of maximum dose rate 0020s 0080s 30% of maximum dose rate 0030s 0070s 40% of maximum dose rate 0040s 0060s 50% of maximum dose rate 0050s 0050s 60% of maximum dose rate 0060s 0040s 70% of maximum dose rate 0070s 0030s 80% of maximum dose rate 0080s 0020s 90% of maximum dose rate 0090s 0010s 100% of maximum dose rate 0000s 0000s

5.6.2 After Bleed Mode

In After Bleed Mode, the Inhibitor Pump will dose for a proportional time based on the amount of time the bleed was on for.

For example, after a Bleed Cycle, if the total time bleed time (including pauses) was 15 minutes, then the Inhibitor will also dose on a programmable ON/OFF cycle for 15 minutes, commencing immediately after the 15 minute bleed cycle is complete.

The example on the following page explains programming an After Bleed ON/OFF cycle time:

NOTE: The Dispersant Setup screens are identical to that of the

Inhibitor, but for purposes of illustration, the Inhibitor Setup is shown in the following diagrams:

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Example: With Inhibitor on ‘After Bleed’ mode currently set –

Decreasing Inhibitor pump duty cycle from 50% to 30%

Mode: [After Bleed]

Mode: [After Bleed] ON Period: 0050s OFF Period: 0050s

Mode: [After Bleed] ON Period: 0050s OFF Period: 0050s

Mode: [After Bleed] ON Period: 0030s OFF Period: 0050s

Mode: [After Bleed] ON Period: 0030s OFF Period: 0050s

Mode: [After Bleed] ON Period: 0030s OFF Period: 0050s

► INHIBITOR SETUP

DISPERSANT SETUP BIOCIDE TIMERS

Mode: [After Bleed] ON Period: 0030s OFF Period: 0070s

5.6.3 Twenty Four Hour Per Day (24hr/day) Cycle

In this mode, the Inhibitor Pump will dose on a continuous duty cycle all day, every day. The Duty cycle is repeating ON / OFF times, eg ON=30sec, followed by OFF=570sec & repeating (i.e. 5% duty cycle).

An example of the 24hr/day cycle is shown on the following page:

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Example: With Inhibitor on “24hr/day” mode currently set – Setting the Inhibitor

pump to repeat dose for 30 seconds followed by a 600 second off period

Inhibitor: [24hr/day]

Inhibitor: [24hr/day] On Period: 0050s Off Period: 0050s

► INHIBITOR SETUP

DISPERSANT SETUP BIOCIDE TIMERS

Inhibitor: [24hr/day] On Period: 0050s Off Period: 0050s

Inhibitor: [24hr/day] On Period: 0030s Off Period: 0650s

Inhibitor: [24hr/day] On Period: 0030s Off Period: 0050s

Inhibitor: [24hr/day] On Period: 0030s Off Period: 0050s

Inhibitor: [24hr/day] On Period: 0030s Off Period: 0600s

Inhibitor: [24hr/day] On Period: 0030s Off Period: 0650s

5.6.4 Make-Up Water Pulses

In this mode, the Inhibitor Pump doses proportional to pulses received from a water meter fitted in the Make-Up line. The DIGICHEM Plus+ activates the pump for a set time once a pre-determined number of pulses is counted, explained further in the following example:

Water meter pulse rate = 1 pulse / litre Desired concentration = 100 p.p.m.

[100 p.p.m. = 10ml chemical / 100 litres flow = 10ml chemical / 100 pulses]

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Hence, we require the pump to dose 10ml every 100 pulses counted.

How long does the pump need to dose to deliver 10ml?

Pump dose rate = 1300ml/hr = 0.36ml/sec Dose time = 10ml / 0.36ml/sec = 27.8 seconds (i.e. approx. 30 sec)

Set PULSE COUNT = 100 Set DOSE PERIOD = 30 seconds

In the example above, the pump doses for 30 seconds (i.e. programmed dose time) every 100 litres of make-up water (i.e. programmed pulse count of 100).

The example below explains setting up the pulse count and dose time:

Example: With Inhibitor on “Make-Up Pulses” mode currently set – Setting the

Inhibitor pump to dose for 15 seconds after 10 pulses from a water meter

Mode: [MakeUP Pulses]

Mode: [MakeUp Pulses] Pulse Count: 0050p Dose Period: 0050s

► INHIBITOR SETUP

DISPERSANT SETUP BIOCIDE TIMERS

Mode: [MakeUp Pulses] Pulse Count: 0050p Dose Period: 0050s

Mode: [MakeUp Pulses] Pulse Count: 0010p Dose Period: 0050s

Mode: [MakeUp Pulses] Pulse Count: 0010p Dose Period: 0050s

Mode: [MakeUp Pulses] Pulse Count: 0010p Dose Period: 0050s

Mode: [MakeUp Pulses] Pulse Count: 0010p Dose Period: 0015s

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5.6.5 Bleed Water Pulses

In this mode, the Inhibitor Pump doses proportional to pulses received from a water meter fitted in the Bleed line. The DIGICHEM Plus+ activates the pump for a set time once a pre-determined number of pulses is counted.

Select the mode of “Bleed Pulses” in the Inhibitor Setup menu (Explained in Section 5.6) and see the example above from section 5.6.4 Make-Up Water Pulses.

Notes: (v0.91 or later) A ‘+’ will be displayed on the LCD screen momentarily for a make-up pulse and a ‘-’ will be displayed for a Bleed pulse.

5.7 Biocide Setup

Main Menu > SETUP MENU > GENERAL SETUP > BIOCIDE TIMERS

Biocide is dosed according to 28 day timer programs set up by the user. There are 10 independent programs which can be programmed to operate daily, once per week, or on any number of days per week, fortnightly or once a month. A typical biocide program, which will operate at the same time on the specified days of the week, consists of 3 consecutive time durations:

1. Pre-bleed

2. Biocide Dosing

3. Bleed Lock-out

1. Pre-bleed

This reduces the system conductivity to a lower temporary setpoint (eg. 85% of setpoint) prior to biocide dosing in order to allow for a longer Bleed Lock-out duration without the risk of entering scaling conditions. Pre-bleed duration is programmable from 1 minute up to 23 hours. (Note: The Pre-Bleed Setpoint of 85%, ie. Setpoint -15% is fully programmable, and is explained further in section 5.8).

2. Biocide dosing

The biocide pump (Pump A or Pump B/ORP) doses chemical, typically into a manifold. Dose duration is programmable from 1 minute up to 23 hours and commences immediately after Pre-Bleed. Bleed-off is disabled (ie. locked out) during dosing provided the Bleed Lock-out setpoint is not exceeded. If ORP control is enabled, Pre-Bleed and BleedLockout are only applicable to Biocide A.

3. Bleed Lock-out

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After biocide dosing, bleed-off continues to be disabled for the lock-out duration, programmable from 1 minute up to 23 hours, provided the Bleed Lock-out setpoint is not exceeded. (Note: The default Bleed Lockout Setpoint of Setpoint +20% is fully programmable, and is explained

further in section 5.9). By preventing bleed-off during and after biocide dosing, the system is ensured of receiving maximum benefit from the dosed biocide, as no biocide will be lost during this time via bleed-off. Furthermore, because the conductivity is reduced during Pre-Bleed, the system has a longer retention period. As a result, a highly effective “kill” is achieved without resulting in high scaling conditions.

Each of the 10 Biocide Dosing programs can be set up to operate Biocide pump A or Biocide pump B/ORP. In other words, the programs can be allocated in any combination to either of the two biocide outputs, A and B/ORP.

For instance, if pump A is set up in 6 programs, pump B/ORP can only have up to 4 programs controlling it. Not all of the programs need to be allocated. If only two of the programs are required, then the other 8 will remain disabled. Pump A and Pump B/ORP work totally independently and each program has its own START TIME, followed by its own consecutive PRE-BLEED, BIOCIDE DOSING and BLEED LOCK-OUT durations. However, biocide programs

should not overlap. NOTE: When a timer program is initially entered, the controller will control as

per normal, until the end of the timer program. At the end of the timer program, the outputs will then go into an “Idle” state. The outputs will be in an “Idle” state until the Timer program is activated again.

Main Menu > SETUP MENU > GENERAL SETUP > BIOCIDE TIMERS

► BIOCIDE TIMERS

PRE-BLEED SETPOINT BLD LOCKOUT SETP.

Timer Program: [01]

Press or to scroll through biocide timer programs

Press at any time to select program

Timer Program: [02]

Timer Program: [10]

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The example on the following page illustrates setting up Timer Program [01] for Pump A:

Note: If ORP is disabled, then Pump B will be displayed as an option. If ORP

is enabled, then ORP/pH will be displayed as an option.

Main Menu > SETUP MENU > GENERAL SETUP > BIOCIDE TIMERS > TIMER >

PROGRAM [01]

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Select O/P: [None ]

Select O/P: [Pump A]

Week:1234

N NNN

Week:1234

NY NY

DAY: S M T W T F S

N Y N Y N Y N

Start Time: 00:00 Dose for: 00h00m

Pre-Bleed: 00h00m Bleed L/O: 00h00m

Use the , and pushbuttons to select the start time (i.e. commence pre-bleed) and the dose period

Start Time: 16:00 Dose for: 01h30m

Example: Selecting Biocide Program 1, for pump A to dose on Mon, Wed, Friday in Weeks 2 & 4, with a 45m pre-

bleed starting at 16h00, thereafter dosing for 1h30m, with an additional bleed lockout of 2h30m

Timer Program: [01]

DAY: S M T W T F S

N N N N N N N

Use the , and pushbuttons to select the pre-bleed and bleed lockout times

Pre-Bleed: 00h45m Bleed L/O: 02h30m

For each week, press or to toggle between Yes and No, then press

For each day, press or to toggle between Yes and No, then press

Press or to toggle between Pump A, B & Aux. (ORP disabled) or Pump A, ORP/pH & Aux. (ORP enabled)

However, this menu will change, if ORP is enabled.

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The example below shows the menu structure using the previous example, where instead of Pump A, the ORP/pH Output will be activated:

NOTE: For this selection, Pre-Bleed and Bleed Lockout will not appear in the

menu, or the Main screen when the controller is inside or outside of an active period.

Select O/P: [None ]

Select O/P: [ORP/pH]

Week:1234

N NNN

Week:1234

NY NY

DAY: S M T W T F S

N Y N Y N Y N

Start Time: 00:00 Active for: 00h00m

Use the , and pushbuttons to select the start time and the active period

Start Time: 16:00 Active for: 01h30m

Example: Selecting Biocide Program 1, for the ORP & pH control functions to be active on Mon, Wed,

Friday in Weeks 2 & 4, active for 1h30m, commencing at 16h00. Therefore the ORP & pH

control only occur betweeen 16h00 and 17h30 on the days selected.

Timer Program: [01]

DAY: S M T W T F S

N N N N N N N

For each week, press or to toggle between Yes and No, then press

For each day, press or to toggle between Yes and No, then press

Press or to toggle between Pump A, B & Aux. (ORP disabled) or Pump A, ORP/pH & Aux. (ORP enabled)

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The Auxiliary (Aux.) output can also be switched from a timer, as per the example below:

Select O/P: [None ]

Week:1234

N NNN

Week:1234

NY NY

DAY: S M T W T F S

N Y N Y N Y N

Start Time: 00:00 Active for: 00h00m

Use the , and pushbuttons to select the start time and the active period

Start Time: 16:00 Dose for: 01h30m

Example: Selecting Biocide Program 1, for the Aux. control function to be active on Mon, Wed,

Friday in Weeks 2 & 4, active for 1h30m, commencing at 16h00.

Timer Program: [01]

DAY: S M T W T F S

N N N N N N N

For each week, press or to toggle between Yes and No, then press

For each day, press or to toggle between Yes and No, then press

Press or to toggle between Pump A, B & Aux. (ORP disabled) or Pump A, ORP/pH & Aux. (ORP enabled)

Select O/P: [AUX. ]

NOTE: Aux. output is only available from software version 0.83 and later.

When the Aux. output is activated, the main screen will display “AUX.” at the bottom.

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5.8 Pre-Bleed Setpoint

Main Menu > SETUP MENU > GENERAL SETUP > PRE-BLEED SETPOINT

In the example above, the Pre-Bleed setpoint is set as the Normal Conductivity Setpoint less 15%. Hence, during the Pre-bleed time (ie. Immediately before biocide dosing), the normal conductivity setpoint is reduced by 15%, and the controller will try to maintain this reduced setpoint until biocide dosing commences. The objective of pre-bleed is to allow for a longer Bleed Lock-out duration without the risk of entering scaling conditions.

5.9 Bleed Lock-out Setpoint

Main Menu > SETUP MENU > GENERAL SETUP > BLD LOCKOUT SETP.

In the example above, the Lockout setpoint is set as the Normal Conductivity Setpoint plus 50%. Hence, during Biocide Dosing and during the Lockout time (ie. Immediately after biocide dosing), the normal conductivity setpoint is

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increased by 50%, and the controller will try to maintain this increased setpoint until the Lockout Period expires. By preventing bleed-off during and after biocide dosing, the system is ensured of receiving maximum benefit from the dosed biocide, as no biocide will be lost during this time via bleed-off. Furthermore, because the conductivity is reduced during Pre-Bleed, the system has a longer retention period. As a result, a highly effective “kill” is achieved without resulting in high scaling conditions.

5.10 Condenser Pump Timer

Main Menu > SETUP MENU > GENERAL SETUP > CONDENSR PMP TIMER

Example: Setting the Condenser Pump Timer for 15 minutes

►

CONDENSR PMP TIMER

FLOW SWITCH START-UP DELAY

Biocide dose + 000m

Biocide dose + 015m

Often when biocides are dosed into the manifold of the DIGICHEM Plus+ systems, the circulating/ condenser pump of the cooling tower is not running. This can cause problems of clogging and corrosion in the manifold, as well as biocide not being dosed into the cooling tower water.

The DIGICHEM Plus+ controller has an on-board relay contact (N/O) which can be wired into the condenser pump contactor (see wiring diagram in section

2.1). The contact provided is a dry contact (i.e. volt free) so it can be connected in series with the condenser pump contactor circuit, or any other circuit as required. Alternatively, the relay contact can power the contactor by looping 240VAC active to the common of the relay contact and connecting the N/O contact to the coil of the contactor. Note: In this instance, the contactor must have a 240VAC coil and must be normally powered from the same 240VAC mains circuit as the DIGICHEM Plus+.

Do NOT connect a Condenser pump or Re-circulation pump directly to this output.

When either biocide pump starts dosing (except Biocide B if set to dose on ORP), the N/O contact closes, powering the contactor which in turn starts the condenser pump. The condenser pump will continue to run while the biocide is

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dosing, as well as for a period of time after biocide dosing. This ensures continuous water circulation and effective mixing of the biocide chemical. The time that the pump runs AFTER a biocide dose, is programmed here as the Condenser Pump Timer.

IMPORTANT: If this feature is used, it is not recommended to switch the

condenser pump on and off rapidly using the output test feature, explained in section 4.4

The following is another example of a biocide program set to dose on a weekly cycle:

Start time: 07:00

Pre-Bleed: 00h60m (ie. 07h00 to 08h00)

Dose for: 00h60m (ie. 08h00 to 09h00)

Bleed L/O: 04h00m (ie. 09h00 to 13h00)

Other Program Settings

Setpoint = 1000 TDS

Pre Bleed Setpoint = Setpoint – 13% (ie. 870 TDS)

Bleed Lock-out Setpoint = Setpoint + 50% (ie. 1500 TDS)

Program = 01

Pump = A

Condenser Pump Timer = 30m (i.e. delay off time after A dose)

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5.11 Flow Switch

Main Menu > SETUP MENU > GENERAL SETUP > FLOW SWITCH

With a flow switch connected to the controller, any or all of the outputs can be disabled when there is no flow. An output, when selected via this menu for flow detection, will stop immediately if no flow is detected. For example, when bleeding, the solenoid valve will close immediately if no flow is detected.

There are 3 possible settings in the menu for the flow switch logic:

• DISABLE: All outputs active when required, regardless of flow or no flow

• NORMAL: Enabled outputs activate when required, only if the flow switch

input is shorted

• REVERSE: Enabled outputs activate when required, only if the flow switch input is open circuit

Flow Switch Setup Menu

► FLOW SWITCH

START-UP DELAY INHIBITOR SETUP

Logic: [DISABLE]

Logic: [REVERSE]

Logic: [NORMAL ]

Press or to scroll through flow switch logic

Press at any time to select flow logic

The Flow Switch can disable either one or any combination of the 6 outputs if there is no flow. Typically, the Bleed, Inhibitor, pH & ORP outputs are disabled if there is no flow and the Non-Oxidising Biocides dose during their programs regardless of the flow status. However, either or both of the Biocide outputs can be set to be disabled if there is no flow.

NOTE: Upon resumption of flow, if a Start-Up delay time has been

programmed, the controller will only start controlling after this time.

See Section 4.1.1 – pg 12 for Start-Up delay programming. Please see the example on the following page demonstrating the enabling of

the flow switch for various outputs:

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Should the flow switch be disabled altogether, please see example on the following page:

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Example: Disabling Flow Switch Operation from Normal Logic

► FLOW SWITCH

START-UP DELAY INHIBITOR SETUP

Logic: [NORMAL ]

Logic: [DISABLE]

5.12 Advanced Setup Menu

Main Menu > SETUP MENU > ADVANCED SETUP

The Advanced Setup Menu has the following features:

• Data Logging – Log Process Variables on a time basis

• Disinfection – Program a weekly slug dose

• Extra Inhibitor Dose – Additional Inhibitor Dose to decrease scaling

• Water Volume Counters – Log Make-Up and Bleed Water Volumes

• Cycles of Concentration – Measured Conductivity / Make-Up Conductivity

• Password Setup – Setup Access Rights to Controller

• Controller Name – Assign a unique name to the controller

• Site Name – Assign a unique name to the site where the controller is

installed

• Remote Coms – Enable GSM/GPRS Modem if fitted

• LCD Contrast – Adjust the intensity of the LCD screen display (Software

ver 0.80 & later)

The diagram on the following page illustrates how to navigate through the Advanced Setup Menu:

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Advanced Setup Menu

► ADVANCED SETUP

μ S/TDS SETUP ORP SETUP

► DATA LOGGING

DISINFECTION XTRA INHIBTR DOSE

► WATER VOL COUNTERS

CYCLES OF CONCENT. PASSWORD SETUP

► CONTROLLER NAME

SITE NAME REMOTE COMS.

X 3

X 1

► LCD CONTRAST

DATA LOGGING DISINFECTION

X 3

X 1

5.12.1 Data Logging

Main Menu > SETUP MENU > ADVANCED SETUP > DATA LOGGING

IMPORTANT: If the Logging Interval is changed, all previous Logs will be erased. (Software v0.91 or later will warn you of this when changing)

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The controller has the facility to log the following items at pre-programmed intervals:

Name Description Range Example

Date Date stamp of log N/A 08/07/2008 Time Time stamp of log N/A 12:45 Conductivity Conductivity/TDS of water 0 – 10000 1024 Temperature

Temperature of water in °C

0 – 100 20 pH pH of water 0.01 – 13.99 7.40 ORP mV of water 0 – 999 606 Auxiliary Input1 Spare Analogue input (4-20mA) 0.0 – 10000 125 Auxiliary Input2 Spare Analogue input (4-20mA) 0.0 – 10000 125 Cycles of Concentration

The cooling water conductivity divided by the makeup water conductivity

0 – 1000 5.1

MakeUp water Volume of water makeup in litres 0 – 20000 5400 Bleed water Volume of bleed water in litres 0 – 20000 200 Evaporation & Losses

Volume of water lost due to evaporation and other losses

0 – 9999 1234

Bleed% Percentage of the log period the Bleed

output being active for

0 – 100 0

Inhibitor% Percentage of the log period the

Inhibitor output being active for

0 – 100 20

BioA% Percentage of the log period the

Biocide ‘A’ output being active for

0 – 100 0

BioB%/ORP Percentage of the log period the Bio

‘B’ or ORP output active for

0 – 100 45

pH% Percentage of the log period the pH

output being active for

0 – 100 20

Dispersant% Percentage of the log period the

dispersant output being active for

0 – 100 10

Aux% (SW ver

0.83 and later)

Percentage of the log period the Aux. output being active for

0 – 100 0

Alarm% Percentage of the log period the Alarm

output being active for

0 – 100 0

Flow% Percentage of the log period the flow

switch was being active for

0 – 100 0

Alarm Override Boolean 1 for true or 0 for false. 0 or 1 0 Tank 1: Inhib. Level LOW