CWC DIGICHEM-XP2 User manual

Instruction Manual
Cooling Water Treatment Controller
Model: DIGICHEM-XP2
Biocide A
Power
Bleed
Biocide B
Inhibitor
Alarm
Time & Date
UP
Main Menu
DOWN
Reset
ENTER
Water Treatment Controller
Comms
Supplied by:
Convergent Water Controls Pty Ltd
2/4 Huntley Street, PO Box 7058
Alexandria NSW 2015
t: [phone] w: cwc.com.au
f: [phone] e: [email protected]
M1 ver 1.5
Fill in serial
number here Ö
Refer to
back page

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.

T
Ta ab bl le e o of f C Co on nt te en nt ts s
1. Introduction...........................................................................................................................7
2. Installation ............................................................................................................................7
2.1 Electrical Wiring...........................................................................................................................7
2.2 Conductivity Probe Installation & Maintenance...............................................................................8
3. Controller Functionality.........................................................................................................9
3.1 Menu Logic.................................................................................................................................. 9
3.2 Pushbuttons .............................................................................................................................. 10
3.3 LED Indication........................................................................................................................... 11
3.4 Comms Port............................................................................................................................... 12
4. Commissioning.....................................................................................................................13
4.1 Start-Up .................................................................................................................................... 13
4.2 Setting Time & Date................................................................................................................... 14
4.3 Calibration................................................................................................................................. 15
4.4 Testing Relay Outputs................................................................................................................ 18
4.5 Manual Dose.............................................................................................................................. 19
4.6 View Settings............................................................................................................................. 20
4.7 Factory Settings......................................................................................................................... 20
5. Programming Setup Menu...................................................................................................21
5.1 Set Units ................................................................................................................................... 23
5.2 Set Bleed Setpoint ..................................................................................................................... 23
5.3 Set Hysteresis............................................................................................................................ 24
5.4 Set Bleed Cycle.......................................................................................................................... 25
5.5 Alarm Parameters ...................................................................................................................... 26
5.5.1 High Conductivity Alarm....................................................................................................................27
5.5.2 Low Conductivity Alarm.....................................................................................................................27
5.5.3 No Flow Alarm..................................................................................................................................28
5.5.4 Delay On Alarm................................................................................................................................28
5.5.5 Bld Timer Alarm................................................................................................................................29
5.6 Inhibitor Setup........................................................................................................................... 29
5.7 Biocide Setup............................................................................................................................. 33
5.8 Pre-Bleed Setpoint ..................................................................................................................... 36
5.9 Bleed Lock-out Setpoint.............................................................................................................. 36
5.10 Auxiliary Output On Timer ........................................................................................................ 37
5.11 Flow Switch ............................................................................................................................. 39
5.12 Data Logging........................................................................................................................... 40
6. Factory Settings...................................................................................................................41
7. Specifications.......................................................................................................................42
8. Service & Technical Support................................................................................................43

1. Introduction
Designed for cooling tower water treatment, the DIGICHEM-XP2 electronic
controller incorporates the following key features:
•Conductivity bleed control
•Inhibitor pump dosing control
•Dual Biocide pump control (via 10 independent 28-day timer programs)
•Data logging
•Tower circulating/condenser pump override facility with delay-off timer
•High and Low Conductivity alarms with programmable delay-off timer
2. Installation
Mount the DIGICHEM-XP2 on a flat vertical surface away from extreme heat,
humidity or areas where temperature variations are extreme, ideally at eye-
level to allow good visibility of the LCD display. Also ensure that a 240VAC
mains power point is located nearby.
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.

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The diagrams below shows the connections to the DIGICHEM-XP2 controller
circuitry (release 1 & release 2).
L14
L13
L12
L11
L10
R4
R15
R14
R13
R5
R6
R3
R2
R1
FUSE
2A/250VAC
R20
R19
L9
L8
L7
L6
R10
R11
R12
R9
R8
R7
R18
R17
R16
Release 1
L6: Conductivity Probe PR+ (Brown or Red)
L7: Conductivity Probe PR- (Yellow)
L8: Conductivity Probe CM+ (Blue)
L9: Water Meter In
L10: Flow Switch In
L11: Flow Switch Common / Water Meter Common / Probe
Cable Screen (Grey)
L12 + L14: Alarm Relay N/O volt-free (10A/250VAC res)
L13 + L14: Alarm Relay N/C volt-free (10A/250VAC res)
R1: Mains Active 240VAC (power supply)
R2: Mains Neutral
R3: Auxiliary Continuous Active 240VAC (2A fused)
R4: Auxiliary Neutral
R5: Solenoid Valve Active 240VAC (2A fused)
R6: Solenoid Valve Neutral
R7: Inhibitor Pump Active 240VAC (2A fused)
R8: Inhibitor Pump Neutral
R9: Biocide ‘A’ Active 240VAC (2A fused)
R10: Biocide ‘A’ Neutral

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R11: Biocide ‘B’ Active 240VAC (2A fused)
R12: Biocide ‘B’ Neutral
R13 - R18: Common Earth
R19: Condenser Pump Relay common
R20: Condenser Pump Relay N/O volt-free (10A/250VAC res)
Fuse: 2A/250VAC (M205, 20mm x 5mm diameter)
Notes on Alarm Relay Contacts :
1. Alarm relay is energised (ie. L14 connected to L12) during normal
operation of the unit.
2. Alarm relay de-energises (ie. L14 connected to L13) 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 are required to be connected
to terminals L10 & L11 (not polarity sensitive). The flow switch logic is
programmable via the menu.

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L4
L13
L12
L11
L10
R4
R15
R14
R13
R5
R6
R3
R2
R1
FUSE
2A/250VAC
R20
R19
L9
L8
L7
L6
R10
R11
R12
R9
R8
R7
R18
R17
R16
L5
Release 2
L4: Conductivity Probe Cable Screen (Grey)
L5: Conductivity Probe PR+ (Brown or Red)
L6: Conductivity Probe PR- (Yellow)
L7: Conductivity Probe CM+ (Blue)
L8: Water Meter In
L9: Flow Switch In
L10: Flow Switch Common / Water Meter Common / Probe
Cable Screen (Grey)
L11 + L13: Alarm Relay N/O volt-free (10A/250VAC res)
L12 + L13: Alarm Relay N/C volt-free (10A/250VAC res)
R1: Mains Active 240VAC (power supply)
R2: Mains Neutral
R3: Auxiliary Continuous Active 240VAC (2A fused)
R4: Auxiliary Neutral
R5: Solenoid Valve Active 240VAC (2A fused)
R6: Solenoid Valve Neutral
R7: Inhibitor Pump Active 240VAC (2A fused)
R8: Inhibitor Pump Neutral
R9: Biocide ‘A’ Active 240VAC (2A fused)
R10: Biocide ‘A’ Neutral
R11: Biocide ‘B’ Active 240VAC (2A fused)

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R12: Biocide ‘B’ Neutral
R13 - R18: Common Earth
R19: Condenser Pump Relay common
R20: Condenser Pump Relay N/O volt-free (10A/250VAC res)
Fuse: 2A/250VAC (M205, 20mm x 5mm diameter)
Notes on Alarm Relay Contacts :
1. Alarm relay is energised (ie. L13 connected to L11) during normal
operation of the unit.
2. Alarm relay de-energises (ie. L13 connected to L12) 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 are required to be connected
to terminals L9 & L10 (not polarity sensitive). The flow switch logic is
programmable via the menu.
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:
DIRECTION
OF FLOW

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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.
3. Controller Functionality
3.1 Menu Logic
The DIGICHEM-XP2 has an advanced but very user-friendly menu system:
•The menu structure is circular
•The relevant menu item, or programmed value flashes
•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 LCD is backlit
The MAIN MENU of the controller is illustrated as follows (see next page):

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MANUAL DOSE
EXIT
SETUP MENU
FACTORY SETTINGS
TEST OUTPUTS
CALIBRATE
TIME & DATE
VIEW SETTINGS
995 TDS [1000]
Hold
To access
menu item
press
3.2 Pushbuttons
The DIGICHEM-XP2 has 3 pushbuttons which each have dual functions:
1. Scroll UP (Time & Date)
2. Scroll DOWN (Main Menu)
3. ENTER (Reset)
•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.

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•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:
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-XP2, hold down the Scroll DOWN
(Main Menu) pushbutton. The display will count down until you access the
menus.
•If you wish to cancel an alarm or any timers activated, press and hold the
ENTER (Reset) pushbutton until the display says:
3.3 LED Indication
There are 6 LEDs on the front face of the DIGICHEM-XP2:
•Power (green): illuminates continuously when power is applied to the
controller
•Bleed (amber): illuminates continuously when power is applied to the
solenoid output of the controller. If the solenoid output
is suspended due to a pause in the bleed cycle, the LED
will flash on and off.
•Biocide A (amber):illuminates continuously when power is applied to the
Biocide A output of the controller.
•Biocide B (amber):illuminates continuously when power is applied to the
Biocide B output of the controller.
•Inhibitor (amber): illuminates continuously when power is applied to the
Inhibitor output of the controller. If the Inhibitor output
is suspended due to no flow, the LED will flash on and
off during the ON cycle.

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•Alarm (red): illuminates when the alarm relay switches. If the alarm
delay is timing before the alarm condition is confirmed,
the LED will flash on and off.
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.

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4. Commissioning
CAUTION: Refer to previous section before reading this section
4.1 Start-Up
Power up the controller after installation. After a start-up sequence, the
controller automatically goes into NOR AL ODE. 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), as follows:
NOTE: An asterisk ‘*’ flashes on the screen when the controller receives a
pulse from an optional water meter (Software version 2.0 and above). The
asterisk '*' may appear on the LHS of the display or within the square brackets
just before the Conductivity Setpoint or Temperature.
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, e.g.
•When a flow switch is connected to the controller, each output is
suspended when there is no flow past the flow switch, if the output is
selected via the Flow Switch enu.

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4.2 Setting Time & Date
Main Menu > TIME & DATE
TIME: 10:30
TIME: 11:00
TIME: 10:00
DATE: 1 Jan 2006
DATE: 2 Jan 2006
DATE: 2 Nov 2006
TIME & DATE
Press or to change day
then
Press or to change month
Press or to change year
Example: Setting time & date to 10:30 on 2 Nov 2006
NOTE: The Week No will be automatically set

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4.3 Calibration
IMPORTANT: Select the display in either µS or TDS before proceeding.
(Refer section 5.1)
Calibrating the SLOPE
Main Menu > CALIBRATE
Take a sample of water from the sample valve on the manifold and
measure the conductivity with a 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.

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Calibrating the ZERO
The zero is factory set so should not require calibration. However, if the
display reads above zero with the conductivity probe disconnected,
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 into the Calibrate Menu and set the Zero Calibration (see below).
5. Screw the probe back into the manifold.
6. Perform the SLOPE calibration again.

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Resetting the CALIBRATION
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.

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4.4 Testing Relay Outputs
Main Menu > TEST OUTPUTS
Bleed O/P[OFF]
TEST OUTPUTS
BIO ‘A’ O/P [OFF] Press or to turn ON
AUX. O/P [OFF]
ALARM O/P [OFF]
BIO ‘B’ O/P [OFF]
INHIBTR O/P [OFF]
Press or to turn ON
Press or to turn ON
Press or to turn ON
Press or to turn ON
Press or to turn ON
When any of the Outputs is activated, the respective Output LED illuminates
and the Output relay switches, putting 240VAC power onto the output terminal,
which activates the pump or solenoid valve wired to it.
When the Alarm Output is activated, the red Alarm LED illuminates and the
relay de-energises, switching the Common from the Normally Open Contact to
the Normally Closed contact of the Alarm relay.
NOTES:
1. If any output is activated manually without reverting back to the de-
activated 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 Aux O/P On relay rapidly ON and OFF, if powering the
condenser pump of the cooling tower.

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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) as follows:
Note: The pump will not dose if there is no flow
To cancel a manual dose, press and hold the ENTER (Reset)
pushbutton

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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:
HYSTERESIS 10%
Display: [TDS]
SETPOINT: 1000
ID: 0620-65535
10 P00h00 L00h00
VIEW SETTINGS
Press at any point to escape
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.