Walchem WDT400 Series User manual

W
DT400 Controllers
W A L C H E M
IWAKI America Inc.
WDT400 Series
Dual Cooling Tower
Conductivity Controller
Instruction Manual
Five Boynton Road Hopping Brook Park Holliston, MA 01746 USA
TEL: [phone] FAX: [phone] WEB: www.walchem.com

Notice
© 2014 WALCHEM, Iwaki America Inc.(hereinafter “Walchem”)
Five Boynton Road, Holliston, MA 01746 USA
[phone]
All Rights Reserved
Printed in USA
Proprietary Material
The information and descriptions contained herein are the property of WALCHEM. Such information and
descriptions may not be copied or reproduced by any means, or disseminated or distributed without the
express prior written permission of WALCHEM, Five Boynton Road, Holliston, MA 01746.
Statement of Limited Warranty
WALCHEM warrants equipment of its manufacture, and bearing its identification to be free from
defects in workmanship and material for a period of 24 months for electronics and 12 months for
mechanical parts and electrodes from date of delivery from the factory or authorized distributor
under normal use and service and otherwise when such equipment is used in accordance with
instructions furnished by WALCHEM and for the purposes disclosed in writing a the time of
purchase, if any. WALCHEM’s liability under this warranty shall be limited to replacement or
repair, F.O.B. Holliston, MA U.S.A. of any defective equipment or part which, having been
returned to WALCHEM, transportation charges prepaid, has been inspected and determined by
WALCHEM to be defective. Replacement elastomeric parts and glass components are expendable
and are not covered by any warranty.
THIS WARRANTY IS IN LIEU OF ANY OTHER WARRANTY, EITHER EXPRESS OR IMPLIED,
AS TO DESCRIPTION, QUALITY, MERCHANTABILITY, and FITNESS FOR ANY
PARTICULAR PURPOSE OR USE, OR ANY OTHER MATTER.
180331 Rev. L
April 2014

Table of Contents
1.0 INTRODUCTION.....................................................................................................................1
2.0 SPECIFICATIONS..................................................................................................................2
2.1 Measurement Performance.................................................................................................2
2.2 Electrical: Input/Output........................................................................................................2
2.3 Mechanical..........................................................................................................................2
2.4 WDT Variables and their Limits...........................................................................................3
3.0 UNPACKING & INSTALLATION.............................................................................................4
3.1 Unpacking the unit...............................................................................................................4
3.2 Mounting the electronic enclosure.......................................................................................4
3.3 Installation...........................................................................................................................4
3.4 Icon Definitions....................................................................................................................6
3.5 Electrical installation............................................................................................................6
4.0 FUNCTION OVERVIEW ....................................................................................................... 10
4.1 Front Panel........................................................................................................................ 10
4.2 Display .............................................................................................................................. 10
4.3 Keypad..............................................................................................................................11
4.4 Access Code.....................................................................................................................11
4.5 Startup...............................................................................................................................11
4.6 Shut Down.........................................................................................................................11
5.0 OPERATION......................................................................................................................... 12
5.1 Main Menu ........................................................................................................................ 12
5.2 Conductivity (A or B) Menu ............................................................................................... 14
5.3 Temperature (A or B) Menu .............................................................................................. 16
5.4 Bleed (A or B) Menu..........................................................................................................17
5.5 Feed (A or B) Menu...........................................................................................................18
5.6 WM1 and WM2 Menu........................................................................................................20
5.7 Alarm (A or B) Menu.......................................................................................................... 21
5.8 Time Menu ........................................................................................................................22
5.9 4-20mA (A or B) Menu ...................................................................................................... 23
5.10 Access Code Menu........................................................................................................... 24
5.11 Datalog Menu.................................................................................................................... 25
5.12 Config Menu...................................................................................................................... 26
5.13 Upgrade Menu ..................................................................................................................27
6.0 MAINTENANCE....................................................................................................................28
6.1 Electrode Cleaning............................................................................................................28
6.2 Replacing the Fuses..........................................................................................................29
7.0 TROUBLESHOOTING..........................................................................................................29
7.1 Error Messages.................................................................................................................29
7.2 Conductivity Readout Does Not Change...........................................................................31
7.3 Procedure for evaluation of the conductivity electrode.....................................................31
7.4 Procedure for checking relay outputs................................................................................ 32
8.0 SERVICE POLICY................................................................................................................32

1.0 INTRODUCTION
The Walchem WDT400 Series controllers offer conductivity control of cooling tower water and control
of corrosion/scale inhibitor feed. The inhibitor pump may be selected to operate in one of the following
modes:
Feed and Bleed
Feed and Bleed with Lockout
Feed as a percent of Bleed
Feed as a percent of Time
Feed based on a Water Contactor input
Feed based on a Paddlewheel input
The WDT series cooling tower controllers are supplied with temperature compensated electrodes with a
cell constant of 1.0. The controllers are microprocessor driven industrial type with on/off control
outputs. A timed sample mode may be selected, and on small towers can reduce installation costs by
eliminating the need for a sampling bypass line. One or two optional isolated 4-20 mA outputs that are
proportional to the conductivity reading are available for all models.
Any set point may be viewed without interrupting control. Each set point change will take effect as soon
as it is entered. An access code is available to protect set point parameters, while still allowing settings
to be viewed.
All outputs are interlocked with a flow switch input.
An alarm relay is provided with WDT400 models. It is triggered by:
Temp A or B Error
Cond A or B Error
No Flow Tower A or B
Bleed A or B Timeout
Feed A or B Timeout
Tower A or B Hi Alarm
Tower A or B Lo Alarm
Our unique USB feature provides the ability to upgrade the software in the controller to the latest
version.
An advanced USB capability option is available. The Config file feature allows you to save all the set
points from a controller onto a USB flash disk, and then import them into another controller, making the
programming of multiple controllers fast and easy. The data logging feature allows you to save the last
2 month’s readings and events to a USB flash disk.
1

2.0 SPECIFICATIONS
2.1 Measurement Performance
Conductivity Range 0 - 10,000 µS/cm (microSiemens/centimeter)
Conductivity Resolution 1 µS/cm
Conductivity Accuracy 10 - 10,000 µS/cm ± 1% of reading
0 - 10 µS/cm ± 20% of reading
Temperature Range 32 – 158°F (0 – 70°C)
Temperature Resolution 0.1°C
Temperature Accuracy ± 1% of reading
2.2 Electrical: Input/Output
Input Power 100-240 VAC, 50/60 Hz, 8A
Fuse: 1.0 ampere, 5 x 20 mm
Input Signals
Conductivity Electrode 1.0 cell factor, 10K thermistor
Flow Meter (0, 1 or 2 optional) Isolated, dry contact closure required (i.e. relay, reed switch)
Flow Switch (0, 1 or 2 optional) Isolated, dry contact closure required (i.e. reed switch)
Outputs Mechanical Relays (5) Pre-powered on circuit board switching line voltage
6 A (resistive), 1/8 HP
All relays are fused together as one group, total current for this
group must not exceed 6A
4 - 20 mA (0,1, or 2 optional) Fully isolated
600 Ohm max resistive load
Resolution .001% of span
Accuracy ± 1% of reading
Agency Approvals Safety UL 61010-1:2012 3rd Ed.
CSA C22.2 No. 61010-1:2012 3rd Ed.
IEC 61010-1:2010 3rd Ed.
EN 61010-1:2010 3rd Ed.
EMC IEC 61326-1:2005
EN 61326-1:2006
Note: For EN61000-4-6, EN61000-4-3 the controller met performance criteria B.
*Class A equipment: Equipment suitable for use in establishments other than domestic, and those directly
connected to a low voltage (100-240 VAC) power supply network which supplies buildings used for
domestic purposes.
2.3 Mechanical
Enclosure Material Polycarbonate
NEMA Rating NEMA 4X
Dimensions 8.5" x 6.5" x 5.5"
Display 2 x 16 character backlit liquid crystal
Operating Ambient Temp 32 – 122°F (0 – 50°C)
Storage Temperature -20 – 180°F (-29 – 80°C)
Graphite electrode pressure rating 150 psi
Flow switch manifold pressure rating 150 psi
Flow switch manifold connections ¾" NPTF
2

2.4 WDT Variables and their Limits Low Limit High Limit
Conductivity menu PPM Conversion Factor 0.200 ppm/µS/cm 1.000 ppm/µS/cm
Interval Time (sampling) 5 minutes 24:00 hours
Duration Time (sampling) 1 minute 59 min: 59 sec
% Calibration Range -50 +50
Temperature Menu No variables
Bleed Menu Set Point 0 µS/cm 10,000 µS/cm
Dead Band 5 µS/cm 500 µS/cm
Bleed Limit Time (set in hours/minutes) 1 minute 8 hrs: 20 min
(enabled)
0=unlimited (disabled)
Feed Menu Feed Lockout Timer (Mode A) 1 second 99 min: 59 sec
Percent of Bleed (Mode B) 5 % 99 %
Feed Time Limit (Mode B) 1 minute 99 min: 59 sec
Percent of Time (Mode C) 5 % 99 %
Feed Cycle Time (Mode C) 10 minutes 59 min: 59 sec
Time per Contact (Mode D) 1 second 59 min: 59 sec
÷ Contacts by (Mode D) 1 contact 100 contacts
Time Limit (Mode D & E) 1 minute 99 min: 59 sec
Time/Vol (Mode E) 1 second 59 min: 59 sec
Vol to Initiate Feed (Mode E) 1 9,999
WM1 and WM2 Menus Gallons per Contact 1 gal/contact 500 gal/contact
Liters per Contact 1 L/contact 500 L/contact
K Factor (Paddlewheel) 0.01 pulse/vol 999.99 pulses/vol
4-20 mA Menus 4 & 20 mA Settings 0 µS/cm 10,000 µS/cm
Access Code New Value 0 9999
Alarms Menu* High & Low (set to zero to disable) 1% 50%
Datalog Menu (Optional) No variables
Config Menu (Optional) No variables
Upgrade Menu No variables
*Note: The Alarm relay is non-programmable. Refer to the Main Menu diagram on page 16 for the list of error
conditions that trigger the alarm relay.
3

3.0 UNPACKING & INSTALLATION
3.1 Unpacking the unit
Inspect the contents of the carton. Please notify the carrier immediately if there are any signs of damage
to the controller or its parts. Contact your distributor if any of the parts are missing. The carton should
contain: a WDT400 series controller and instruction manual. Any options or accessories will be
incorporated as ordered.
3.2 Mounting the electronic enclosure
The WDT series controller is supplied with mounting holes on the enclosure. It should be wall mounted
with the display at eye level, on a vibration-free surface, utilizing all four mounting holes for maximum
stability. Use M6 (1/4" diameter) fasteners that are appropriate for the substrate material of the wall.
The enclosure is NEMA 4X rated. The maximum operating ambient temperature is 122°F (50°C); this
should be considered if installation is in a high temperature location. The enclosure requires the
following clearances:
Top: 2" (50 mm)
Left: 8" (203 mm)
Right: 4" (102 mm)
Bottom: 7" (178 mm)
3.3 Installation
Once the WDT series controller is mounted, the metering pumps may be located at any distance from
the controller. The conductivity electrodes should be placed as close to the controller as possible, to a
maximum distance of 250 ft. Under 25 ft is recommended. The cable must be shielded from background
electrical noise. Always route low voltage (sensor) signals with at least a 6” separation from AC voltage
wiring.
Locate the electrode tees where an active sample of cooling tower water is available and where the
electrode can easily be removed for cleaning. They must be situated so that the tee is always full and the
electrode is never subjected to a drop in water level resulting in dryness. Refer to Figure 1 for typical
installation.
IMPORTANT: To avoid cracking the female pipe threads on the supplied plumbing parts, use no more
than 3 wraps of Teflon® tape and thread in the pipe FINGER tight plus ½ turn! Do not use pipe dope to
seal the threads of the flow switch because the clear plastic will crack!
4

I
COO
LIN
G
T
O
WER
BLEED METERING
VALVE PUMP
HEAT
EXCHANGER
System A
Cooling Tower Controller
www.walchem.com
PREV NEXT
ENTER EX T
COOLING TOWER
BLEED
VALVE METERING
PUMP
HEAT
EXCHANGER
System B
Figure 1 Typical Installation
5

3.4 Icon Definitions
Symbol Publication Description
IEC 417, No.5019 Protective Conductor Terminal
IEC 417, No. 5007 On (Supply)
IEC 417, No. 5008 Off (Supply)
ISO 3864, No. B.3.6 Caution, risk of electric shock
ISO 3864, No. B.3.1 Caution
3.5 Electrical installation
The various standard wiring options are shown in figure 2, below. Your WDT series controller will
arrive from the factory prewired or ready for hardwiring. Depending on your configuration of controller
options, you may be required to hardwire some or all of the input/output devices. Refer to figures 3 and
4 for circuit board layout and wiring.
Note: when wiring the optional flow meter contactor input, the 4-20 mA output or a remote flow switch,
it is advisable to use stranded, twisted, shield pair wire between 22-26 AWG. Shield should be
terminated at the controller ground stud (see figures 3 and 4).
CAUTION
1. There are live circuits inside the controller even when the power switch on the front panel is in
the OFF position! The front panel must never be opened before power to the controller is
REMOVED!
If your controller is prewired, it is supplied with a 8 foot, 18 AWG power cord with USA style
plug. A tool (#1 Phillips driver) is required to open the front panel.
2. When mounting the controller, make sure there is clear access to the disconnecting device!
3. The electrical installation of the controller must be done by trained personnel only and
conform to all applicable National, State and Local codes!
4. Proper grounding of this product is required. Any attempt to bypass the grounding will
compromise the safety of persons and property.
5. Operating this product in a manner not specified by Walchem may impair the protection
provided by the equipment.
6

BLEED BFEED B SPARES 4-20 mA (2)
(optional)
CONDUCTIVIT
Y
ELECTRODE B
CO
NDU
C
TIVITY
ELECTRODE A
FLOW SWITCH A
(OPTIONAL)
POWER
BLEED A
ALARM
4-20 mA (1)
(optional) FLOW METER B
(OPTIONAL) FLOW SWITCH B
(OPTIONAL)
FLOW METER A
(OPTIONAL)
FEED A
Figure 2 Conduit/Wiring Configuration
7

GREEN
WHITE
GRN120V
GRN/YEL240V
BLK 120V
BRN240V
GREEN
WHITE
R- R+ R- R+
L2 L2
BLEED
N.C. N.O. FEED N.C. N.O.
F1
L1 L2/N
F2
GROUND
STUD
COND
T+ T-
RED BLK
+5V
FLOW SW 1 FLOW SW 2 FLOW MTR 2
FLOW MTR 1
IN+ IN- IN+ IN- IN+ IN- IN+
COND
RED BLK
+5V
T+ T-
SYSTEM B
L1 L2/N
COND
T+ T-
+5V
RED BLK
WHT 120V
BLU 240V
SYSTEM A
SHIELD
SYSTEM B
SYSTEM A
COND
T+ T-
+5V
RED BLK
FLOW SW 1 FLOW SW 2 FLOW MTR 2
FLOW MTR 1
IN+ IN- IN+ IN- IN+
IN+ IN-
SHIELD
Conductivity
Electrode
Contact Closure:
Polarity not critical Hall Effect
Flow Meter
Power Supply
(115 VAC or 230 VAC)
Figure 3 Inputs
Reed Switch
Flow Meter
Polarity not Critical
Conductivity
Electrode
8

System
A
System B
Chart Chart
Recorder Recorder
BLEED FEED BOI 1 BIO 2 ALARM
L2 L2 L2 L2 L2 L2
N.C. N.O. N.C. N.O. N.C. N.O. N.C. N.O. N.C. N.O. N.C. N.O.
COND
T+ T-
RED BLK
+5V
FLOW SW 1 FLOW SW 2
FLOW MTR 1 FLOW MTR 2
IN+ IN- IN+ IN- IN+
IN+ IN-
COND
T+ T-
RED BLK
+5V
L1 L2/N
GROUND
STUD
GRN 120V
GRN 120V GRN/YEL 240V
GRN/YEL 240V
BLEED B
BLEED A FEED A FEED B ALARM
L2/N L2/N L2/N L2/N L2/N L2/N N.C. N.O. N.C. N.O. N.C. N.O. N.C. N.O. N.C. N.O.
WHT 120V BLU 240V
WHT 120V BLU 240V WHT 120V BLU 240V
WHT 120V BLU 240V
BLK 120V BRN 240V
BLK 120V BRN 240V
IF MOTORIZED BALL VALVE
BLK 120V BRN 240V BLK 120V BRN 240V
WHT 120V
BLU 240V
BLK 120V BRN 240V
IF MOTORIZED
BALL VALVE
GRN 120V
GRN/YEL 240V
TO GROUND
STUD
GRN 120V
GRN/YEL 240V
TO GROUND
STUD
GRN 120V
GRN/YEL 240V
TO GROUND
STUD
Bleed Solenoid/
Motorized Ball Valve
NOTE: When connecting a
motorized ball valve, the pre-wired
pigtail must be removed and the
valve requires two wires, one to
N.O. to open the valve and one to
N.C. to close the valve.
Bleed
Solenoid/
Motorized
Ball Valve
A
larm
Pum
p
Pum
p
Figure 4 Outputs
9

4.0 FUNCTION OVERVIEW
4.1 Front Panel
On/Off Power Switch
Backlit LCD Display
Out
p
ut LEDs
Setting Adjustment Keys
Menu/Function Ke
y
s
USB Connector
USB LED
Figure 5 Front Panel
4.2 Display
A summary screen is displayed while the WDT controller is on. This display shows the conductivity of
tower A on the upper left side, tower B on the upper right side and current operating conditions. The
operating conditions that are displayed on the bottom line of this display are Temp Err A, Temp Err B,
Cond Err A, Cond Err B, No Flow A, No Flow B, Bleed Timeout A, Bleed Timeout B, Feed Timeout
A, Feed Timeout B, Hi Alarm A, Hi Alarm B, Lo Alarm A, Lo Alarm B, Bleed A, Bleed B, Feed A,
Feed B, Waiting A/B, Sample A/B, Extend A/B and Normal. Normal just means there is nothing
unusual to report.
2000 2010
Normal
Figure 6 Summary Screen
10

4.3 Keypad
The keypad consists of 4 directional arrow keys and 4 function keys. The arrows are used to move the
adjustment cursor and change settings, while the function keys are used to enter values, and navigate the
various menu screens. The function keys are ENTER, EXIT, NEXT, and PREV (previous). NEXT and
PREV scroll through the various menu choices. ENTER is used to enter a submenu and to enter a value.
EXIT is used to back up one menu level. If you are at the main menu level, EXIT will return you to the
Summary Display.
To change a value in a submenu, the left/right arrow keys move the cursor left and right to each digit or
option that can be changed. The up/down arrows will change numeric values up or down, or scroll
through option choices. Press
ENTER only when you have finished making all of the changes for that
menu screen.
4.4 Access Code
The WDT series controller is shipped with the access code disabled. If you wish to enable it, see
Section 5.11 for operation. With the access code enabled, any user can view parameter settings, but not
change them. Note that this provides protection only against casual tampering. Use a lock on the cover
latch if you need more protection.
4.5 Startup
Initial Startup
After having mounted the enclosure and wired the unit, the controller is ready to be started.
Plug in the controller and turn on the power switch to supply power to the unit. The display will briefly
show the WDT model number and then revert to the normal summary display. Scroll through the menus
and calibrate the conductivity reading, temperature, and set the control parameters detailed in Section 5,
Operation.
To return to the summary display, press the
EXIT key until you return to this screen. The controller will
automatically return to this screen after 10 minutes.
Normal Startup
Startup is a simple process once your set points are in memory. Simply check your supply of chemicals,
turn on the controller, calibrate it if necessary and it will start controlling.
4.6 Shut Down
To shut the WDT controller down, simply turn off the power. Programming remains in memory.
11

5.0 OPERATION
These units control continuously while power is applied. Programming is accomplished via the local
keypad and display.
To view the top level menu, press any key. The menu structure is grouped by inputs and outputs. Each
input has its own menu for calibration and unit selection as needed. Each output has its own setup menu
including set points, timer values and operating modes as needed. After ten minutes of inactivity in the
menu, the display will return to the summary display. Keep in mind that even while browsing through
menus, the unit is still controlling.
5.1 Main Menu
The exact configuration of your WDT controller determines which menus are available as you scroll
through the settings. Certain menus are only available if you select certain options.
Main Menu Top Level
Tower A
Tower B
Access Code
Datalog Only if advanced USB feature is in model code
Config Only if advanced USB feature is in model code
Upgrade
Inside Tower A and B menus
Conductivity A or B
Temperature A or B
Bleed A or B
Feed A or B
WM1 or WM2 Only if Feed based on Water Contactor or Paddlewheel
Alarm
4-20mA A or B Only if 4-20mA option board(s) installed.
The NEXT key travels forward through this list while the PREV key travels backwards through the list.
Pressing ENTER will Enter the lower level menu that is currently displayed.
The following menu descriptions work exactly the same way for cooling tower A as for cooling tower
B.
12

Possible status screens
Main Menu
Figure 7 Main Menu
13
A 1000 B 1000 NORMAL
EXIT ENTER
Tower A A 1000 B 1000
EXIT ENTER
A 1000 S 77°F Conductivity

*Temp Err A
*Temp Err B
*Cond Err A
*Cond Err B
*No Flow A
*No Flow B
*Bleed Timeout A
*Bleed Timeout B
*Feed Timeout A
*Feed Timeout B
*Hi Alarm A
*Hi Alarm B
*Lo Alarm A
*Lo Alarm B
Bleed A
Bleed B
Feed A
Feed B
Waiting A/B
Sample A/B
Holding A/B
Stops Conductivity Control
*
These conditions trip the
diagnostic alarm relay.
Operation
Press Enter key to enter menu. Press Exit key to exit menu. Blinking fields may be edited with the adjust arrows. Press Enter when modification is complete to return to Main Menu Level.
A 1000 B 1000 Tower B A 1000 B 1000
Access Code
Same as A
Normal
A 1000 B 1000 Datalog A 1000 B 1000
Config A 1000 B 1000
Upgrade
A 1000 B 1000 Time:SUN 3:00
A: 1000 S 77°F Temperature

A: 1000 S 77°F Bleed

A: 1000 S 77°F Feed

A: 1000 S 77°F Alarm

A: 1000 S 77°F 4-20 mA

A: 1000 S 77°F WM1 1000Gal


5.2 Conductivity (A or B) Menu
The conductivity menu provides the following settings: Calibration, Self Test, Unit selection, and
sampling mode setup. Additional settings are also discussed below. Refer to figure 8, Conductivity
Menu Chart.
Calibrate To Calibrate the conductivity, use either a hand held meter, or a buffer solution, and adjust the WDT controller to
match. Once Calibrate is entered, the unit continuously displays conductivity readings. Press an arrow key to
change the value displayed to match the hand held meter or the buffer solution. You must press ENTER to activate
the new calibration. You must press the EXIT key to exit calibration. The Bleed output is unaffected until the
calibration menu is exited, so if it was ON when you entered calibration it will stay on until you exit.
Self Test Press ENTER to begin self test. Press any key to stop. Self Test internally simulates a conductivity sensor and
should always give the reading 1000 µS/cm ± 100 µS. If it does not, there is a problem with the electronics and the
unit should be serviced. If the self test is in the expected range, and there is a problem calibrating, then the sensor
or its wiring is at fault.
Units You may choose to display conductivity in µS/cm or in ppm. Press ENTER and then use the Up and Down arrows
to change the units. If you change the units, you will be warned to check your settings. This is important. Set points
are not automatically translated from µS/cm to ppm. If you change the units you will need to change your Bleed
settings.
ppm C.F. This is the ppm Conversion Factor (or multiplier). This is typically 0.666 but can be changed to accommodate
various requirements.
Sample
Mode C / I
Press enter to choose Continuous sampling or Intermittent sampling. A 'C' at the end of the display means that
sampling is continuous, while an 'I' indicates intermittent sampling. Use Continuous sampling with a traditional
bypass line installation of the conductivity sensor. Choose Intermittent sampling to use the bleed solenoid valve for
timed sampling of the conductivity.
Intermittent sampling installations read the conductivity at set intervals for a given sample duration. If the
conductivity is above the set point, the valve that controls the sampling will stay open until the conductivity falls
below the set point. If the time the valve stays open goes beyond the sample duration, the controller will display
Extend on the top status line, as well as the amount of time extended. A limit on this amount of time may be
imposed; see Figure 10 Bleed Menu.
Continuous
Intermittent
If Intermittent sampling is chosen, the Flow Switch input will be ignored, and the following two settings will
become available:
Interval This sets the amount of time between samples. This is set in Hours:Minutes. The minimum is 5 minutes. The
maximum is 24 hours.
Duration This is the length of each sample. This is set in Minutes:Seconds. The minimum is 1 minute. The maximum is 59
minutes; 59 seconds.
RawCond This menu is for information only and displays the temperature-compensated conductivity reading before the user’s
calibration has been applied.
14

Possible status screens
Conductivity A or B Menu
Calibrate Cond
2000 S/cm

Cond Self Test
1000 S/cm

Cond Self Test
1000 ppm
Units S/cm
S/cm


Units ppm
ppm
Sample Mode C
Continuous
Sample Mode I
Intermittent
. . . . WARNING . . . .
Adjust Set Point
Cond 2000
Calibrate
 S
A: 2000 S 68° F
Conductivity

Cond
Self Test
2000 S 
Cond
Units S/cm
2000 S 

Cond
ppm C.F. 0.666
2000 S 
Cond
Sample Mode C
2000 S 
Cond Wait 23:50
Cond Samp 10:00
Cond Hold :59
Calibrate Cond
1333 ppm
ENTEREXIT
ENTER
EXIT
NEXTPREV.
ENTER
EXIT ENTER
EXIT
Cond Xtend 10:00
1
1 1 1 2
ENTER
EXIT
2 2

2000
Interval (H) 3:59
Cond 2000 S Cond
 S
Duration 2:00 Cond
RawCond 2000 µS
2000 µS
Legend Operation
Menu choices that appear when ppm units are Press Enter key to enter menu.
selected. Press Exit key to exit menu.
Blinking fields may be edited with the adjust arrows.
Menu choices that appear when Intermittent Press Enter when modification is complete to return
Sampling is selected. to Conductivity Menu Level.
Figure 8 Conductivity (A or B) Menu
2
1
15

5.3 Temperature (A or B) Menu
The Temperature menu contains the following settings: Calibration and Unit selection . The
Temperature menu will be indicated on the display by one of the following:
Temperature Normal operation
Temp 70°F Normal operation
Temp Error Indicates that there is a problem with the temperature input. See Figure 9.
Calibrate To Calibrate the Temperature, use a thermometer to measure the fluid temperature and adjust the WDT controller to
match. Once Calibrate is entered, the unit continuously displays temperature readings. Press the Up or Down arrow
key to change the value displayed to match the thermometer. You must press ENTER to activate the new calibration.
You must press the EXIT key to exit calibration.
Man Temp This menu appears only if no temperature element is connected at power-up. Use the arrow keys to adjust the
temperature displayed to match that of the water.
Units You may choose to display temperature in °C or °F. Press ENTER and the Up or Down Arrow keys to change the
temperature units for display.
Mode Press ENTER and use the UP or DOWN arrow keys to select between Manual Temperature Compensation (used with
sensors that do not have a temperature measuring element in them) or Automatic Temperature Compensation. If
Automatic is selected, and the temperature element is not detected, the controller will display a Temp Error and revert
to Manual Temp Comp until the signal is restored.
Calibrate
Temp °F 68 Units °F
°F
Units °C
°C
Temp 68°F
Calibrate Temp 68°F
Man Temp 68
2000 s 68° F
Temperature
Temp 68°F
Units °F
ENTEREXIT
ENTER
EXIT ENTER
EXIT
NEXTPREV.
Mode Man
Manual Temp Comp
Mode Man
Auto Temp Comp
Temp 68°F
Mode Manual
ENTER
EXIT
2
Calibrate
Temp °C 20.1
1
Possible Status Screen
Temperature Menu
Temperature Err
Legend
Menu wording that appears when Automatic Temperature Compensation is selected.
Menu wording that appears when Manual Temperature Compensation is selected.
2
1
Figure 9 Temperature Menu
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5.4 Bleed (A or B) Menu
The Bleed Menu provides the following settings: Set Point, Dead Band, Control Direction, HOA. The
Bleed menu will be indicated on the display by one of the following: (The 'A' indicates that the output
is being controlled automatically.)
Bleed A OFF Indicates that the bleed output is currently OFF.
Bleed A 10:00 Indicates the length of time that the Bleed output has been ON.
Bleed A NO FLOW Indicates that bleed control has been suspended because there is presently no flow past the flow
switch.
Bleed A LOCKOUT Indicates that the output is currently locked out due to a biocide add or biocide lockout.
Bleed A TIMEOUT Indicates that the feed lockout timer in the Bleed and Feed mode has expired.
Set Point This is the conductivity value at which the bleed solenoid valve is turned ON. The factory default setting for the
WDT controller is for the Bleed output to turn on when the conductivity is higher than the set point. This may be
changed at the Control Direction screen.
Dead Band This is the conductivity value that when combined with the set point determines when the bleed output turns OFF.
Assuming that the control direction is set for normal operation (High Set Point) the bleed output will turn off when
the conductivity drops below the set point minus the Dead Band. For example: The set point is 1500 µS/cm and the
Dead Band is 200 µS/cm. The bleed output turns ON when the conductivity reading is greater than 1500 but does
not turn OFF until the conductivity drops below 1300.
Time Limit This menu allows you to set a maximum amount of time for the bleed. The limit time is programmed in hours and
minutes and can be set between 1 minute and 8 hrs: 20 minutes. If the time limit is set to zero, then the valve may
be open indefinitely. If the maximum time is exceeded, the bleed valve will close and will not re-open until the
"Reset Timer" menu is reset by an operator.
Reset Timer Only appears if the time limit above has been exceeded. Use the up or down arrow to change "N" to "Y", then
press ENTER.
Control Dir
H / L
This allows you to set the Normal (High Set Point) or Inverse (Low Set Point) operation of the bleed output. When
set to High, the output turns on when the conductivity is higher than the set point. When set to Low, the output
turns on when the conductivity is lower than the set point.
High Set Point Low Set point
H O A The "Hand Off Auto" screen allows you to select the operating mode of the bleed output. In Hand (manual) mode,
the output is turned on immediately for a maximum of 10 minutes. If you walk away the output will return to Auto
mode at the end of that time. In Off mode the output will stay Off indefinitely. In Auto mode the bleed output will
respond to changes in conductivity based on the set point. The HOA mode of the bleed output is indicated on the
bleed status lines.
Figure 10 Bleed (A or B) Menu
17