IWAKI AMERICA WCT900 User manual

Five Boynton Road Hopping Brook Park Holliston, MA 01746 USA
TEL: [phone] WEB: www.walchem.com
W900 Series
Water Treatment Controller
Instruction Manual

Notice
© 2021 WALCHEM, Iwaki America Incorporated (hereinafter “Walchem”)
5 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 per-
mission of WALCHEM, 5 Boynton Road, Holliston, MA 01746.
This document is for information purposes only and is subject to change without notice.
Statement of Limited Warranty
WALCHEM warrants equipment of its manufacture, and bearing its identication 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 at 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. Replaceable 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, FITNESS FOR ANY PARTICULAR PURPOSE OR USE, OR ANY OTHER MATTER.
180686 Rev. H February 2021

Contents
1.0 INTRODUCTION ..................................................................................... 1
2.0 SPECIFICATIONS................................................................................... 2
2.1 Measurement Performance ....................................................................................... 2
2.2 Electrical: Input/Output .............................................................................................. 4
2.3 Mechanical ................................................................................................................ 6
2.4 Variables and their Limits........................................................................................... 7
3.0 UNPACKING & INSTALLATION........................................................... 11
3.1 Unpacking the unit ................................................................................................... 11
3.2 Mounting the electronic enclosure ........................................................................... 11
3.3 Sensor Installation ................................................................................................... 11
3.4 IconDenitions ........................................................................................................ 14
3.5 Electrical installation ................................................................................................ 15
4.0 FUNCTION OVERVIEW........................................................................ 33
4.1 Front Panel .............................................................................................................. 33
4.2 Touchscreen ............................................................................................................ 33
4.3 Icons ....................................................................................................................... 33
4.4 Startup ..................................................................................................................... 35
4.5 Shut Down ............................................................................................................... 44
5.0 OPERATION using the touchscreen .................................................. 44
5.1 Alarms Menu .......................................................................................................... 44
5.2 Inputs Menu ............................................................................................................ 44
5.2.1 Contacting Conductivity .................................................................................. 48
5.2.2 Electrodeless Conductivity ...................................................................................48
5.2.3 Temperature .........................................................................................................49
5.2.4 pH.........................................................................................................................49
5.2.5 ORP......................................................................................................................50
5.2.6 Disinfection...........................................................................................................50
5.2.7 Generic Sensor ...................................................................................................51
5.2.8 Corrosion Input.....................................................................................................52
5.2.9 Corrosion Imbalance Input ...................................................................................53
5.2.10 Transmitter Input and AI Monitor Input .................................................................54
5.2.11 Fluorometer Input .................................................................................................54
5.2.12 Analog Flowmeter Input.............................................................................................55
5.2.13 Analog Tank Level Input .......................................................................................55
5.2.14 DI State.................................................................................................................56
5.2.15 Flow Meter, Contactor Type ............................................................................ 56
5.2.16 Flow Meter, Paddlewheel Type.............................................................................57
5.2.17 Feed Monitor ........................................................................................................58
5.2.18 DI Counter Input ...................................................................................................59
5.2.19 Remote Modbus DI State....................................................................................60
5.2.20 Virtual Input – Calculation.....................................................................................61
5.2.21 Virtual Input – Redundant.....................................................................................62
5.2.22 Virtual Input – Raw Value .....................................................................................63
5.2.23 Virtual Input - Disturbance....................................................................................63
5.2.24 Remote Modbus Sensor Virtual Input ..................................................................65

5.3 Outputs Menu .............................................................................................................65
5.3.1 Relay, Any Control Mode ......................................................................................66
5.3.2 Relay,On/O󰀨ControlMode .................................................................................66
5.3.3 Relay, Flow Timer Control Mode ..........................................................................67
5.3.4 Relay, Bleed and Feed Control Mode...................................................................67
5.3.5 Relay, Bleed then Feed Control Mode..................................................................68
5.3.6 Relay, Percent Timer Control Mode......................................................................68
5.3.7 Relay, Biocide Timer Control Mode ......................................................................68
5.3.8 Relay, Alarm Output Mode....................................................................................70
5.3.9 Relay, Time Proportional Control Mode................................................................70
5.3.10 Relay, Intermittent Sampling Control Mode ..........................................................71
5.3.11 Relay, Manual Mode.............................................................................................72
5.3.12 Relay, Pulse Proportional Control Mode...............................................................72
5.3.13 Relay, PID Control Mode ......................................................................................73
5.3.14 Relay, Dual Set Point Mode..................................................................................75
5.3.15 Relay, Timer Control Mode ...................................................................................76
5.3.16 Relay, Probe Wash Control Mode ........................................................................77
5.3.17 Relay, Spike Control Mode ...................................................................................78
5.3.18 Relay Output, Flow Proportional Mode ........................................................... 80
5.3.19 Relay, Target PPM Control Mode .................................................................... 81
5.3.20 Relay, PPM by Volume Control Mode .................................................................82
5.3.21 Relay, Flow Proportional Mode.............................................................................83
5.3.22 Relay, Counter Timer Control Mode .....................................................................84
5.3.23 RelayOutput,On/O󰀨DisturbanceControlMode .................................................84
5.3.24 Relay Output, Volumetric Blending Control Mode ................................................85
5.3.25 Relay, Dual Switch Control Mode ..................................................................... 86
5.3.26 Relay, Boolean Logic Control Mode................................................................ 86
5.3.27 Relay or Analog Output, Lag Control Mode .................................................... 87
5.3.28 Relay Output, Flow Meter Ratio Control Mode.....................................................93
5.3.29 Relay or Analog Output, Disturbance Variable Control Mode...............................94
5.3.30 Analog Output, Proportional Control Mode...........................................................95
5.3.31 Analog Output, Flow Proportional Mode...............................................................96
5.3.32 Analog Output, PID Control Mode........................................................................97
5.3.33 Analog Output, Manual Mode...............................................................................99
5.3.34 Analog Output, Retransmit Mode .........................................................................99
5.4 CongurationMenu ..................................................................................................100
5.4.1 Global Settings ...................................................................................................100
5.4.2 Security Settings.................................................................................................100
5.4.3 Ethernet Settings...............................................................................................100
5.4.4 Ethernet Details..................................................................................................101
5.4.5 WiFi Settings ......................................................................................................101
5.4.6 WiFi Details ........................................................................................................102
5.4.7 Remote Communications (Modbus and BACnet)...............................................103
5.4.8 Email Report Settings.........................................................................................104
5.4.9 Display Settings..................................................................................................105
5.4.10 File Utilities ........................................................................................................105
5.4.11 Controller Details................................................................................................106
5.5 HOA Menu ........................................................................................................... 107
5.6 Graph Menu ......................................................................................................... 107
6.0 OPERATION using Ethernet ............................................................. 108
6.1 Connecting to a LAN.............................................................................................. 108

e
6.1.1 Using DHCP .....................................................................................................108
6.1.2 UsingaxedIPAddress ..................................................................................109
6.2 Connecting Directly to a Computer...................................................................... 109
6.3 Navigating the web pages ................................................................................... 109
6.4 Graphs Webpage................................................................................................. 110
6.5 Software Upgrade................................................................................................ 110
6.6 Notepad Menu .....................................................................................................111
6.7 Remote Sensor Calibration ...................................................................................111
7.0 MAINTENANCE .................................................................................111
7.1 Electrode Cleaning..........................................................................................111
7.2 Replacing the Fuse Protecting Powered Relays............................................ 112
8.0 TROUBLESHOOTING .......................................................................112
8.1 Calibration Failure...................................................................................................112
8.1.1 Contacting Conductivity Sensors ..................................................................... 112
8.1.2 Electrodeless Conductivity Sensors................................................................. 113
8.1.3 pH Sensors....................................................................................................... 113
8.1.4 ORP Sensors ................................................................................................... 113
8.1.5 Disinfection Sensors......................................................................................... 113
8.1.6 Analog Inputs ................................................................................................. 114
8.1.7 Temperature Sensors ....................................................................................... 114
8.1.8 Corrosion Inputs............................................................................................... 114
8.2 Alarm Messages .................................................................................................. 114
8.3 Procedure for Evaluation of Conductivity Electrode ............................................ 119
8.4 Procedure for Evaluation of the pH/ORP Electrode ............................................ 120
8.5 Diagnostic Lights ............................................................................................... 120
9.0 SparePartsIdentication ................................................................122
10.0 Service Policy .................................................................................178

1
1.0 INTRODUCTION
The Walchem W900 Series controllers oer a high level of exibility in controlling water treatment applications.
• There are four slots that accept a variety of Input/Output Modules, which provides unparalleled versatility. Dual sensor
input modules are available that are compatible with a variety of sensors (two sensors per module):
»Contacting conductivity
»Electrodeless conductivity
»pH
»ORP
»Any Walchem disinfection sensor
»Generic sensor (Ion Selective Electrodes or any type of sensor with a linear voltage output between -2 VDC
and 2 VDC)
• Three analog (4-20 mA) input modules with two, four or six input circuits is also available for use with 2,3 or
4-wire transmitters.
• Two other modules feature two or four isolated analog outputs that may be installed to retransmit sensor input signals
to a chart recorder, datalogger, PLC or other device. They may also be connected to valves, actuators or metering
pumps for linear proportional control or PID control.
• Another module combines two analog (4-20 mA) inputs and four analog outputs.
• Eight Virtual Inputs are congurable in the software, to either allow for calculations based on two real inputs, or to
allow to compare values from two sensors to provide redundancy.
• Eight relay outputs may be set to a variety of control modes:
»On/O set point control
»Time Proportional control
»Pulse Proportional control (when purchased with Pulse solid state opto outputs)
»Flow Proportional
»PID control (when purchased with Pulse solid state opto outputs)
»Lead/Lag control of up to 6 relays
»Dual set point
»Timer
»Bleed or Feed based on a Water Contactor or Paddlewheel ow meter input
»Feed and Bleed
»Feed and Bleed with Lockout
»Feed as a percent of Bleed
»Feed as a percent of elapsed time
»Daily, Weekly, 2-week or 4-week Biocide timers with pre-bleed and post-add lockout of bleed
»Intermittent sampling for boilers with proportional blowdown, controlling on a trapped sample
»Always on unless interlocked
»Probe Wash timer
»Spike to alternate set point on timed basis
»Target PPM
»PPM Volume
»Dual Switch
»Boolean Logic
»Diagnostic Alarm triggered by:
• High or Low sensor reading
• No Flow
• Relay output timeout
• Sensor error
Relays are available in several combinations of powered relays, dry contact relays, and pulse solid state opto relays.
Eight Virtual Outputs are congurable in the software, using most of the possible relay or analog output control algo-
rithms, that may be used to interlock or activate actual control outputs.

2
The standard Ethernet feature provides remote access to the controller’s programming via a PC connected directly,
via a local area network, or via Walchem’s Fluent account management server. It also allows emailing of datalog les
(in CSV format, compatible with spreadsheets like Excel) and alarms, to up to eight email addresses. The Modbus
TCP and BACnet remote communications options allow communication with PC-based applications, HMI/SCADA
programs, Building Energy Management systems, Distributed Control Systems (DCS), as well as stand-alone HMI
devices.
Two optional WiFi cards are available, one which allows simultaneous Ethernet and WiFi communications, and one
that increases security by disabling Ethernet when WiFi is enabled. The WiFi can be set to Infrastructure Mode to
provide all the Ethernet functions above, or Ad-Hoc Mode to allow access to the programming wirelessly.
Our USB features provide the ability to upgrade the software in the controller to the latest version. The Cong le feature
allows you to save all the set points from a controller onto a USB ash 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 sensor
readings and relay activation events to a USB ash disk.
2.0 SPECIFICATIONS
2.1 Measurement Performance
pH ORP/ISE
Range -2 to 16 pH units
Resolution 0.01 pH units
Accuracy ± 0.01% of reading
Range -1500 to 1500 mV
Resolution 0.1 mV
Accuracy ± 1 mV
Disinfection Sensors
Range (mV) -2000 to 1500 mV Range (ppm) 0-2 ppm to 0-20,000 ppm
Resolution (mV) 0.1 mV Resolution (ppm) Varies with range and slope
Accuracy (mV) ± 1 mV Accuracy (ppm) Varies with range and slope
100Ω RTD Temperature
Range 23 to 500°F (-5 to 260°C)
Resolution 0.1°F (0.1°C)
Accuracy ± 1% of Reading or ± 1°C, whichever is greater
1000Ω RTD Temperature
Range 23 to 500°F (-5 to 260°C)
Resolution 0.1°F (0.1°C)
Accuracy ± 1% of Reading or ± 0.3°C , whichever is greater
10k or 100k Thermistor Temperature
Range 23 to 194°F (-5 to 90°C)
Resolution 0.1°F (0.1°C)
Accuracy ± 1% of Reading or ± 0.3°C, whichever is greater
Analog (4-20 mA)
Range 0 to 22 mA
Resolution 0.01 mA

3
Accuracy ± 0.5% of reading
Corrosion
Range Resolution
0-2 mpy or mm/year 0.001 mpy or mm/year
0-20 mpy or mm/year 0.01 mpy or mm/year
0-200 mpy or mm/year 0.1 mpy or mm/year
0.01 Cell Contacting Conductivity
Range 0-300 µS/cm
Resolution 0.01 µS/cm, 0.0001 mS/cm, 0.001 mS/m, 0.0001 S/m, 0.01 ppm
Accuracy ± 1% of reading or 0.01 µS/cm, whichever is greater
0.1 Cell Contacting Conductivity
Range 0-3,000 µS/cm
Resolution 0.1 µS/cm, 0.0001 mS/cm, 0.01 mS/m, 0.0001 S/m, 0.1 ppm
Accuracy ± 1% of Reading or 0.1 µS/cm, whichever is greater
1.0 Cell Contacting Conductivity
Range 0-30,000 µS/cm
Resolution 1 µS/cm, 0.001 mS/cm, 0.1 mS/m, 0.0001 S/m, 1 ppm
Accuracy ± 1% of Reading or 1 µS/cm, whichever is greater
10.0 Cell Contacting Conductivity
Range 0-300,000 µS/cm
Resolution 10 µS/cm, 0.01 mS/cm, 1 mS/m, 0.001 S/m, 10 ppm
Accuracy ± 1% of Reading or 10 µS/cm, whichever is greater
Electrodeless Conductivity
Range Resolution Accuracy
500-12,000 µS/cm 1 µS/cm, 0.01 mS/cm, 0.1 mS/m, 0.001 S/m, 1 ppm 1% of reading
3,000-40,000 µS/cm 1 µS/cm, 0.01 mS/cm, 0.1 mS/m, 0.001 S/m, 1 ppm 1% of reading
10,000-150,000 µS/cm 10 µS/cm, 0.1 mS/cm, 1 mS/m, 0.01 S/m, 10 ppm 1% of reading
50,000-500,000 µS/cm 10 µS/cm, 0.1 mS/cm, 1 mS/m, 0.01 S/m, 10 ppm 1% of reading
200,000-2,000,000 µS/cm 100 µS/cm, 0.1 mS/cm, 1 mS/m, 0.1 S/m, 100 ppm 1% of reading

4
Temperature °C Range Multiplier Temperature °C Range Multiplier
0 181.3 80 43.5
10 139.9 90 39.2
15 124.2 100 35.7
20 111.1 110 32.8
25 100.0 120 30.4
30 90.6 130 28.5
35 82.5 140 26.9
40 75.5 150 25.5
50 64.3 160 24.4
60 55.6 170 23.6
70 48.9 180 22.9
Note: Conductivity ranges on page 2 apply at 25°C. At higher temperatures, the range is reduced per the range multiplier
chart.
2.2 Electrical: Input/Output
Input Power 100 to 240 VAC, 50 or 60 Hz, 13 A maximum
Inputs
Sensor Input Signals (0 to 8 depending on model code):
Contacting Conductivity 0.01, 0.1, 1.0, or 10.0 cell constant OR
Electrodeless Conductivity OR
Disinfection OR
Amplied pH, ORP or ISE Requires a preamplied signal. Walchem WEL or WDS series recommended.
±5VDC power available for external preamps.
Each sensor input card contains a temperature input
Temperature 100 or 1000 ohm RTD, 10K or 100K Thermistor
Analog (4-20 mA) Sensor Input (0 to
24 depending on model code):
2-wire loop powered or self-powered transmitters supported
3 or 4 –wire transmitters supported
Two to Six channels per board, depending on model
Channel 1, 130 ohm input resistance
Channel 2-6, 280 ohm input resistance
All channels fully isolated, input and power
Available Power:
One independent isolated 24 VDC ± 15% supply per channel
1.5 W maximum for each channel
Digital Input Signals (12 standard):
State-Type Digital Inputs Electrical: Optically isolated and providing an electrically isolated 12VDC
power with a nominal 2.3mA current when the digital input switch is
closed
Typical response time: < 2 seconds
Devices supported: Any isolated dry contact (i.e. relay, reed switch)
Types: DI State

5
Low Speed Counter-Type Digital
Inputs
Electrical: Optically isolated and providing an electrically isolated 12VDC
power with a nominal 2.3mA current when the digital input switch is
closed 0-20 Hz, 25 msec minimum width
Devices supported: Any device with isolated open drain, open collector,
transistor or reed switch
Types: Contacting Flowmeter, Flow Verify
High Speed Counter-Type Digital
Inputs
Electrical: Optically isolated and providing an electrically isolated 12VDC
power with a nominal 2.3mA current when the digital input switch is
closed, 0-500 Hz, 1.00 msec minimum width. Minimum pulse frequency
for the rate to be displayed: 0.17 Hz
Devices supported: Any device with isolated open drain, open collector,
transistor or reed switch
Types: Paddlewheel Flowmeter, DI Counter
Outputs
Powered mechanical relays (0 to 8
depending on model code):
Pre-powered on circuit board switching line voltage. Two, three or four
relays are fused together (depending on model code) as one group, total
current for this group must not exceed 6 A (resistive), 1/8 HP (93 W)
Dry contact mechanical relays (0 to 8
depending on model code):
6 A (resistive), 1/8 HP (93 W)
Dry contact relays are not fuse protected
Pulse Outputs (0, 2 or 4 depending on
model code):
Opto-isolated, Solid State Relay
200mA, 40 VDC Max.
VLOWMAX = 0.05V @ 18 mA
Accuracy (0-10 Hz): ± 0.5% of Pulse Rate, (10-20 Hz): ± 1.0%,
(20-40 Hz): ± 2.0%
4 - 20 mA (0 to 16 depending on model
code)
Internally powered, 15 VDC, Fully isolated
600 Ohm max resistive load
Resolution 0.0015% of span
Accuracy ± 0.5% of reading
Ethernet 10/100 802.3-2005
Auto MDIX support
Auto Negotiation
Wi-Fi Radio Protocol: IEEE 802.11 b/g/n
Security Protocols (Ad-Hoc Mode): WPA2-Personal
Security Protocols (Infrastructure Mode): WPA/WPA2-Personal, WEP
Certications and Compliance: FCC, IC TELEC, CE/ETSI, RoHS, Wi-Fi
Certied
NOTE on Wi-Fi:
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15
of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequen-
cy energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference
to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in
which case the user will be required to correct the interference at his own expense.
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.

6
EMC IEC 61326-1:2012
EN 61326-1:2013
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
Enclosure Rating NEMA 4X (IP65)
Dimensions 12.2” W x 13.8” H x 5.4” D (310 mm x 351 mm x 137 mm)
Display 320 x 240 pixel monochrome backlit display with touchscreen
Operating Ambient Temp -4 to 122 °F (-20 to 50 °C)
Storage Temperature -4 – 176°F (-20 – 80°C)
Humidity 10 to 90% non-condensing
Mechanical (Sensors) (*see graph)
Sensor Pressure Temperature Materials Process Connections
Electrodeless conductivity 0-150 psi (0-10 bar)* CPVC: 32-158°F (0 to 70°C)*
PEEK: 32-190°F (0 to 88°C)
CPVC, FKM in-line o-ring
PEEK, 316 SS in-line
adapter
1” NPTM submersion
2” NPTM in-line adapter
pH 0-100 psi (0-7 bar)* 50-158°F (10-70°C)* CPVC, Glass, FKM
o-rings, HDPE, Titanium
rod, glass-lled PP tee
1” NPTM submersion
3/4” NPTF in-line tee
ORP 0-100 psi (0-7bar)* 32-158°F (0-70°C)*
Contacting conductivity
(Condensate) 0-200 psi (0-14 bar) 32-248°F (0-120°C) 316SS, PEEK 3/4” NPTM
Contacting conductivity
Graphite (Cooling Tower) 0-150 psi (0-10 bar)* 32-158°F (0-70°C)* Graphite, Glass-lled PP, FKM o-ring 3/4” NPTM
Contacting conductivity SS
(Cooling Tower) 0-150 psi (0-10 bar)* 32-158°F (0-70°C)* 316SS, Glass-lled PP, FKM o-ring 3/4” NPTM
Contacting conductivity
(Boiler) 0-250 psi (0-17 bar) 32-401°F (0-205°C) 316SS, PEEK 3/4” NPTM
Contacting conductivity
(High Pressure Tower) 0-300 psi (0-21 bar)* 32-158°F (0-70°C)* 316SS, PEEK 3/4” NPTM
pH (High Pressure) 0-300 psi (0-21 bar)* 32-275°F (0-135°C)* Glass, Polymer, PTFE,
316SS, FKM 1/2” NPTM gland
ORP (High Pressure) 0-300 psi (0-21 bar)* 32-275°F (0-135°C)* Platinum, Polymer, PTFE,
316SS, FKM 1/2” NPTM gland
Free Chlorine/Bromine 0-14.7 psi (0-1 bar) 32-113°F (0-45°C)
PVC, Polycarbonate,
silicone rubber, SS, PEEK,
FKM, Isoplast
1/4” NPTF Inlet
3/4” NPTF Outlet
Extended pH Range Free
Chlorine/Bromine
0-14.7 psi (0-1 bar) 32-113°F (0-45°C)
Total Chlorine 0-14.7 psi (0-1 bar) 32-113°F (0-45°C)
Chlorine Dioxide 0-14.7 psi (0-1 bar) 32-131°F (0-55°C)
Ozone 0-14.7 psi (0-1 bar) 32-131°F (0-55°C)
Peracetic Acid 0-14.7 psi (0-1 bar) 32-131°F (0-55°C)
Hydrogen Peroxide 0-14.7 psi (0-1 bar) 32-113°F (0-45°C)
Corrosion 0-150 psi (0-10 bar) 32-158°F (0-70°C)* Glass-lled PP, FKM o-ring 3/4” NPTM
Flow switch manifold 0-150 psi (0-10 bar) up to 100°F (38°C)*
0-50 psi (0-3 bar) at 140°F (60°C)
32-140°F (0-60°C) GFRPP, PVC, FKM,
Isoplast
3/4” NPTF
Flow switch manifold
(High Pressure) 0-300 psi (0-21 bar)* 32-158°F (0-70°C)* Carbon steel, Brass, 316SS, FKM 3/4” NPTF

7
pH/ORP
LD2
Cond/Corrosion
HP Cond/Steel
HP pH/ORP/Steel
0
50
100
150
200
250
300
350
30 40 50 60 70 80 90
100 110 120 130 140 150 160 170 180
°F
Pressure (PSI) vs. Temperature (F)
PSI
-1.1 4.4 10.0 15.5 21.1 26.6 32.2 37.7 43.3 48.8 54.4 60.0 65.5 71.1 76.6 82.2
°C
Bar
24.1
20.7
17.2
13.8
10.3
6.9
3.4
HP pH/ORP/Steel
2.4 Variables and their Limits
Sensor Input Settings Low Limit High Limit
Alarm limits Low end of sensor range High end of sensor range
Input alarm dead band Low end of sensor range High end of sensor range
Cell constant (conductivity only) 0.01 10
Smoothing Factor 0% 90%
Temp Comp Factor (conductivity linear ATC only) 0% 20.000%
Installation Factor (Electrodeless conductivity only) 0.5 1.5
Cable length 0.1 3,000
PPM conversion factor (only if units = PPM) 0.001 10.000
Default temperature -20 500
Deadband Low end of sensor range High end of sensor range
Calibration Required Alarm 0 days 365 days
Sensor Slope (Generic sensor only) -1,000,000 1,000,000
Sensor Oset (Generic sensor only) -1,000,000 1,000,000
Low Range (Generic sensor, Virtual Input) -1,000,000 1,000,000
High Range (Generic sensor, Virtual Input) -1,000,000 1,000,000
Constant (Virtual Input only) 10% below Low Range setting 10% above High Range setting
Deviation Alarm (Virtual Input) 10% below Low Range setting 10% above High Range setting
4 mA value (Transmitter, AI Monitor analog input only) 0 100
20 mA value (Transmitter, AI Monitor analog input only) 0 100
Max Sensor Range (Fluorometer analog input only) 0 ppb 100,000 ppb
Dye/Product Ratio (Fluorometer analog input only) 0 ppb/ppm 100 ppb/ppm
Set Flow Total (Flowmeter analog input only) 0 1,000,000,000
Flowmeter Max (Flowmeter analog input only) 0 1,000,000
Input Filter (Flowmeter analog input only) 1 mA 21 mA
Totalizer Alarm (Flowmeter analog input only) 0 2,000,000,000
Min Disturbance (Disturbance Virtual Input only) Low end of sensor range High end of sensor range
Max Disturbance (Disturbance Virtual Input only) Low end of sensor range High end of sensor range

8
Value at Min Disturbance (Disturbance Virtual Input only) 0 100
Value at Max Disturbance (Disturbance Virtual Input only) 0 100
Stabilization Time (Corrosion only) 0 hours 999 hours
Electrode Alarm (Corrosion only) 0 days 365 days
Alloy Multiplier (Corrosion only) 0.2 5.0
Tank Capacity 0 1,000,000
Empty At 0 mA 21 mA
Full At 0 mA 21 mA
Digitalowmeterinputsettings Low Limit High Limit
Totalizer alarm 0 2,000,000,000
Volume/contact for units of Gallons or Liters 1 100,000
Volume/contact for units of m30.001 1,000
K Factor for units of Gallons or Liters 0.01 100,000
K Factor for units of m31 1,000,000
Paddlewheel rate alarm limits 0 High end of sensor range
Paddlewheel rate alarm deadband 0 High end of sensor range
Smoothing Factor 0% 90%
Set Flow Total 0 1,000,000,000
Feed Monitor Input Settings Low Limit High Limit
Totalizer Alarm 0 vol. units 1,000,000 vol. units
Set Flow Total 0 vol. units 1,000,000,000 vol. units
Flow Alarm Delay 00:10 Minutes 59:59 Minutes
Flow Alarm Clear 1 Contact 100,000 Contacts
Dead Band 0% 90%
Reprime Time 00:00 Minutes 59:59 Minutes
Volume/Contact 0.001 ml 1,000.000 ml
Smoothing Factor 0% 90%
Counter Input Settings Low Limit High Limit
DI Counter Rate Alarms 0 30,000
DI Counter Rate Deadband 0 30,000
Totalizer Alarm 0 2,000,000,000
Set Total 0 2,000,000,000
Units per Pulse 0.001 1,000
Smoothing Factor 0% 90%
Remote Modbus Input Settings Low Limit High Limit
Alarm Limits Low end of dened range High end of dened range
Deadband Low end of dened range High end of dened range
Low Range -1,000,000 1,000,000
High Range -1,000,000 1,000,000
Reply Timeout 1 second 15 seconds
Remote Register 0 65535
Update Period 00:01 MM:SS 59:59 MM:SS
Timeout Alarm Delay 00:10 MM:SS 59:59 MM:SS
Relay output settings Low Limit High Limit
Output Limit Time 1 second 86,400 seconds (0 = unlimited)
Hand Time Limit 1 second 86,400 seconds (0 = unlimited)
Daily Max Time 00:01 MM:SS 23:59 MM:SS (0 = unlimited)

9
Min Relay Cycle 0 seconds 300 seconds
Set Point Low end of sensor range High end of sensor range
Spike Set Point (Spike mode) Low end of sensor range High end of sensor range
Onset Time (Spike mode) 0 seconds 23:59:59 HH:MM:SS
Duty Cycle Period (On/O, Spike, Dual Setpoint modes) 0:00 minutes 59:59 minutes
Duty Cycle (On/O, Spike, Dual Setpoint modes) 0% 100%
On Delay Time (Manual, On/O, Dual Setpoint modes,
Dual Switch, Alarm modes, Boolean Logic)
0 seconds 23:59:59 HH:MM:SS
O Delay Time (Manual, On/O, Dual Setpoint modes,
Dual Switch, Alarm modes, Boolean Logic)
0 seconds 23:59:59 HH:MM:SS
Dead Band Low end of sensor range High end of sensor range
Feed duration (Flow Timer, Counter Timer mode) 0 seconds 86,400 seconds
Accumulator Volume (Flow Timer, Target PPM, PPM
Volume, Volumetric Blend, Flow Meter Ratio modes)
1 1,000,000
Accumulator Setpoint (Counter Timer mode) 1 1,000,000
Feed Percentage (Bleed then Feed mode) 0% 1000%
Feed Lockout Time Limit (Bleed & Feed, Bleed then Feed modes) 0 seconds 86,400 seconds
Prebleed To Conductivity (Biocide mode) 1 (0 = no prebleed) High end of sensor range
Prebleed Time (Biocide mode) 0 seconds 86,400 seconds
Bleed Lockout (Biocide mode) 0 seconds 86,400 seconds
Event duration (Biocide, Timer modes) 0 30,000
Proportional band (Time/Pulse Proportional mode,
Intermittent Sampling)
Low end of sensor range High end of sensor range
Sample period (Time Proportional mode) 0 seconds 3600 seconds
Sample Time (Intermittent Sampling mode) 0 seconds 3600 seconds
Hold Time (Probe Wash, Intermittent Sampling modes) 0 seconds 3600 seconds
Maximum Blowdown (Intermittent Sampling mode) 0 seconds 3600 seconds
Wait Time (Intermittent Sampling mode) 0 seconds 86,400 seconds
Max Rate (Pulse Proportional, Pulse PID, Flow Prop
modes)
10 pulses/minute 2400 pulses/minute
Minimum Output (Pulse Proportional, Pulse PID modes) 0% 100%
Maximum Output (Pulse Proportional, Pulse PID modes) 0% 100%
Gain (Pulse PID Standard mode) 0.001 1000.000
Integral Time (Pulse PID Standard mode) 0.001 seconds 1000.000 seconds
Derivative Time (Pulse PID Standard mode)us 0 seconds 1000.000 seconds
Proportional Gain (Pulse PID Parallel mode) 0.001 1000.000
Integral Gain (Pulse PID Parallel mode) 0.001 /second 1000.000 /second
Derivative Gain (Pulse PID Parallel mode) 0 seconds 1000.000 seconds
Input Minimum (Pulse PID modes) Low end of sensor range High end of sensor range
Input Maximum (Pulse PID modes) Low end of sensor range High end of sensor range
Wear Cycle Time (Lag mode) 10 seconds 23:59:59 HH:MM:SS
Delay Time (Lag mode) 0 seconds 23:59:59 HH:MM:SS
Target (Target PPM, PPM Volume modes) 0 ppm 1,000,000 ppm
Pump Capacity (Target PPM, PPM Volume modes) 0 gal/hour or l/hour 10,000 gal/hour or l/hour
Pump Setting (Target PPM, PPM Volume modes) 0% 100%
Specic Gravity (Target PPM, PPM Volume modes) 0 g/ml 9.999 g/ml
Blend Volume (Volumetric Blend mode) 1 1,000,000
Low Cycles Limit (Target PPM, PPM Volume mode) 0 cycles of concentration 100 cycles of concentration

10
Bleed Volume (Flow Meter Ratio mode) 1 1,000,000
Pump Capacity (Flow Prop mode) 0 gal/hour or l/hour 10,000 gal/hour or l/hour
Pump Setting (Flow Prop mode) 0% 100%
Specic Gravity (Flow Prop mode) 0 g/ml 9.999 g/ml
Target (Flow Prop mode) 0 ppm 1,000,000 ppm
Analog (4-20 mA) Output Settings Low Limit High Limit
4 mA Value (Retransmit mode) Low end of sensor range High end of sensor range
20 mA Value (Retransmit mode) Low end of sensor range High end of sensor range
Hand Output 0% 100%
Set Point (Proportional, PID modes) Low end of sensor range High end of sensor range
Proportional Band (Proportional mode) Low end of sensor range High end of sensor range
Minimum Output (Proportional, PID, Disturbance modes) 0% 100%
Maximum Output (Proportional, PID, Disturbance modes) 0% 100%
O Mode Output (Proportional, PID, Flow Prop,
Disturbance modes)
0 mA 21 mA
Error Output (not in Manual mode) 0 mA 21 mA
Hand Time Limit (not in Retransmit mode) 1 second 86,400 seconds (0 = unlimited)
Output Time Limit (Proportional, PID, Disturbance modes) 1 second 86,400 seconds (0 = unlimited)
Gain (PID, Standard mode) 0.001 1000.000
Integral Time (PID Standard mode) 0.001 seconds 1000.000 seconds
Derivative Time (PID Standard mode) 0 seconds 1000.000 seconds
Proportional Gain (PID Parallel mode) 0.001 1000.000
Integral Gain (PID Parallel mode) 0.001 /second 1000.000 /second
Derivative Gain (PID Parallel mode) 0 seconds 1000.000 seconds
Input Minimum (PID modes) Low end of sensor range High end of sensor range
Input Maximum (PID modes) Low end of sensor range High end of sensor range
Pump Capacity (Flow Prop mode) 0 gal/hour or l/hour 10,000 gal/hour or l/hour
Pump Setting (Flow Prop mode) 0% 100%
Specic Gravity (Flow Prop mode) 0 g/ml 9.999 g/ml
Target (Flow Prop mode) 0 ppm 1,000,000 pm
Low Cycles Limit (Flow Proportional mode) 0 cycles of concentration 100 cycles of concentration
Congurationsettings Low Limit High Limit
Local Password 0000 9999
Log in Timeout 10 minutes 1440 minutes
Fluent update period 1 minute 1440 minutes
Fluent reply timeout 10 seconds 60 seconds
Alarm Delay 0:00 minutes 59:59 minutes
SMTP Port 0 65535
TCP Timeout 1 second 240 seconds
Auto Dim Time 0 seconds 23:59:59 HH:MM:SS
Device ID (BACnet) 1 4194302
Data Port (Modbus, BACnet) 1 65535
Ad-Hoc Time Limit 1 min. 1440 min.
Graph settings Low Limit High Limit
Low axis limit Low end of sensor range High end of sensor range
High axis limit Low end of sensor range High end of sensor range

11
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 W900 series controller and an
instruction manual. Any options or accessories will be incorporated as ordered.
3.2 Mounting the electronic enclosure
The 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. Do not install the enclosure
in a location where it will be exposed to direct sunlight. Use M6 (1/4” diameter) fasteners that are appropriate for
the substrate material of the wall. The enclosure is NEMA 4X (IP65) rated. The maximum operating ambient tem-
perature 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: 10” (254 mm)
Right: 4” (102 mm)
Bottom: 7” (178 mm)
3.3 Sensor Installation
Refer to the specic instructions supplied with the sensor being used, for detailed installation instructions.
General Guidelines
Locate the sensors where an active sample of water is available and where the sensors can easily be removed for
cleaning. Position the sensor such that air bubbles will not be trapped within the sensing area. Position the sensor
where sediment or oil will not accumulate within the sensing area.
In-Line Sensor Mounting
In-line mounted sensors must be situated so that the tee is always full and the sensors are never subjected to a
drop in water level resulting in dryness. Refer to Figure 2 for typical installation.
Tap o the discharge side of the recirculation pump to provide a minimum ow of 1 gallon per minute through
the ow switch manifold. The sample must ow into the bottom of the manifold in order to close the ow switch,
and return to a point of lower pressure in order to ensure ow. Install an isolation valve on both sides of the man-
ifold to stop ow for sensor maintenance.
IMPORTANT: To avoid cracking the female pipe threads on the supplied plumbing parts, use no more than 3
wraps of Teon tape and thread in the pipe FINGER tight plus 1/2 turn! Do not use pipe dope to seal the threads
of the ow switch because the clear plastic will crack!
Submersion Sensor Mounting
If the sensors are to be submersed in the process, mount them rmly to the tank, and protect the cable with
plastic pipe, sealed at the top with a cable gland, to prevent premature failure. Place the sensors in an area of good
solution movement.
Sensors should be located such that they respond rapidly to a well-mixed sample of the process water and the
treatment chemicals. If they are too close to the chemical injection point, they will see spikes in concentration
and cycle on and o too frequently. If they are too far away from the chemical injection point, they will respond
too slowly to the concentration changes, and you will overshoot the set point.
The contacting conductivity sensor should be placed as close to the controller as possible, to a maximum
distance of 250 ft. (76 m). Less than 25 ft. (8 m) is recommended. The cable must be shielded from background
electrical noise. Always route low voltage (sensor) signals with at least a 6” (15 cm) separation from AC voltage wiring.
The electrodeless conductivity sensor should be placed as close to the controller as possible, to a maximum
distance of 120 ft. (37 m). Less than 20 ft. (6 m) is recommended. The cable must be shielded from background

12
electrical noise. Always route low voltage (sensor) signals with at least a 6” (15 cm) separation from AC voltage
wiring. These sensors are aected by the geometry and conductivity of their surroundings, so either maintain 6
inches (15 cm) of sample around the sensor or ensure that any nearby conductive or non-conductive items are
consistently positioned. Do not install the sensor in the path of any electrical current that may be owing in the
solution, as this will shift the conductivity reading.
The amplied pH/ORP/ISE electrode should be placed as close to the controller as possible, to a maximum dis-
tance of 1000 feet (305 m) from the controller. A junction box and shielded cable are available to extend the stan-
dard 20 foot (6 m) length. pH and ORP electrodes must be installed such that the measuring surfaces will always
remain wet. A U-trap provided in the manifold design should achieve this, even if the sample ow stops. These
electrodes also must be installed with the measuring surfaces pointing down; that is 5 degrees above the horizontal,
at a minimum. The ow velocity past the sensor must be less than 10 ft./sec. (3 m/sec.)
The disinfection sensor should be placed as close to the controller as possible, to a maximum distance of 100
feet (30 m) from the controller. A junction box and shielded cable are available to extend the standard 20 foot (6
m) length. The sensor should be mounted such that the measuring surfaces will always stay wet. If the membrane
dries out, it will respond slowly to changing disinfectant values for 24 hours, and if dried out repeatedly, will fail
prematurely. The ow cell should be placed on the discharge side of a circulation pump or downhill from a grav-
ity feed. Flow into the cell must come from the bottom side that has the ¾” x ¼” NPT reducing bushing installed.
The reducing bushing provides the ow velocity required for accurate readings and must not be removed! A “U”
trap should be installed so that if the ow stops, the sensor is still immersed in the water. The outlet of the ow
cell must be plumbed to open atmosphere unless the system pressure is at or below 1 atmosphere. If the ow
through the line cannot be stopped to allow for cleaning and calibration of the sensor, then it should be placed in
a by-pass line with isolation valves to allow for sensor removal. Install the sensor vertically, with the measuring
surface pointing down, at least 5 degrees above horizontal. Flow rate regulation must be done upstream from the
sensor, because any ow restriction downstream can increase the pressure above atmospheric and damage the
membrane cap!
The corrosion sensor should be placed as close to the controller as possible, to a maximum distance of 100 feet
(30 m) from the controller. A junction box and shielded cable (p/n 100084) are available to extend the standard
6 foot (3 m) or 20 foot (6 m) length. The sensor should not be installed unless the o-rings/electrodes that match
the metallurgy to be examined are attached to the steel threaded rods. Standard corrosion electrodes are 5 cm2
surface area. Do not touch the metal electrodes; they should be clean and free of any scratches, oils or contami-
nation to accurately measure the corrosion. The sensor should be mounted horizontally, such that the measuring
lbs/hr
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
10 20 30 40 50 60 70 80 90 100 200 300
Pressure PSI
Flow Rate in Lbs/hr for Various Orifices
1/8 inch dia
3/16 inch dia
1/4 inch dia
5/16 inch dia

13
surfaces will always stay completely wet. The sensor should ideally be installed in the side branch of a 1” or ¾”
tee, with the ow entering the tee through the top branch and owing away from the base of the sensor, towards
the tips of the electrodes. A constant ow rate is required, at a minimum of 1.5 gpm (5.7 lpm) with an ideal ow
rate of 5 gpm (19 lpm). If more than one metal is to be used, the most noble metal should be rst.
Important Boiler Sensor Installation Notes: (refer to typical installation drawing)
1. Make sure the minimum water level in the boiler is at least 4-6 inches above the skimmer blowdown line.
If the skimmer line is closer to the surface, it is likely that steam will be drawn into the line instead of boiler
water. The skimmer line must also be installed above the highest tube.
2. Maintain a 3/4 inch minimum pipe ID with no ow restrictions from the tap for the boiler skimmer blow-
down line to the electrode. If the ID is reduced below 3/4 inch, then ashing will occur beyond that point
and the conductivity reading will be low and erratic. Minimize the usage of tees, valves, elbows or unions
between the boiler and the electrode.
3. A manual shut o valve should be installed so that the electrode can be removed and cleaned. This valve
must be a full port valve in order to avoid a ow restriction.
4. Keep the distance between the tap for the boiler skimmer line to the electrode as short as possible, to a maxi-
mum of 10 feet.
5. Mount the electrode in the side branch of a cross in a horizontal run of pipe. This will minimize entrapment
of steam around the electrode and will allow any solids to pass through.
6. There MUST be a ow restriction after the electrode and/or control valve in order to provide back pressure.
This ow restriction will be either a ow control valve or an orice union. The amount of the ow restric-
tion will aect the blowdown rate as well, and should be sized accordingly.
7. Install the motorized ball valve or solenoid valve per the manufacturer’s instructions.
For best results, align the hole in the conductivity electrode such that the direction of water ow is through the
hole.
Guide to Sizing Blowdown Valves and Orice Plates
1. Determine the Rate of Steam Production in Pounds per Hour:
Either read o the boiler name plate (water-tube boilers) or Calculate from horsepower rating (re-tube
boilers): HP x 34.5 = lbs/hr. Example: 100 HP = 3450 lbs/hr.
2. Determine the Concentration Ratio (BASED ON FEEDWATER)
A water treatment chemical specialist should determine the desired number of cycles of concentration. This
is the ratio of TDS in the boiler water to TDS in the feedwater. Note that feedwater means the water that is
fed to the boiler from the deaerator and includes makeup water plus condensate return. Example: 10 cycles
of concentration has been recommended
3. Determine the Required Blowdown Rate in Pounds Per Hour
Blowdown Rate = Steam Production / (Concentration Ratio –1) Example: 3450/(10-1) = 383.33 lbs./hr
4. Determine if Continuous or Intermittent Sampling is Required
Use intermittent sampling when the boiler operation or loading is intermittent, or on boilers where the
required blowdown rate is less than 25% of the smallest available ow control valve or less than the ow
through the smallest orice. See the graphs on the next page.
Use continuous sampling when the boiler is operating 24 hours per day and the required blowdown rate is
more than 25% of the smallest applicable ow control valve or orice. See the graphs on the next page.
Use of a ow control valve will give you the best control of the process, since the ow rate can be easily
adjusted. The dial on the valve also gives you a visual indication if the ow rate has been changed. If the
valve clogs, it can be opened to clear the obstruction, and closed to the previous position.
If an orice plate is used, you must install a valve downstream from the orice in order to ne tune the ow
rate and provide additional back pressure in many applications.
Example: An 80 psi boiler has a Required Blowdown Rate of 383.33 lbs./hr. The maximum ow rate of the

14
smallest ow control valve is 3250 lbs./hr. 3250 x 0.25 = 812.5 which is too high for continuous sampling.
Using an orice, the ow rate through the smallest diameter plate is 1275 lbs./hr. This is too high for continu-
ous sampling.
5. Determine the Orice or Flow Control Valve Size for this Blowdown Rate
Use the following graphs to select a ow control device:
0
5000
10000
15000
20000
25000
20 30 40 50 60 70 80 90 100 150 200 300
Pressure PSI
Flow Control Valve
Maximum Flow Rates in Lbs/hr
1/2" 150 PSI
1/2" 300 PSI
3/4" 150 PSI
3/4" 300 PSI
lbs/hr
3.4 IconDenitions
Symbol Publication Description
IEC 417, No.5019 Protective Conductor Terminal
|IEC 417, No. 5007 On (Supply)
OIEC 417, No. 5008 O (Supply)
ISO 3864, No. B.3.6 Caution, risk of electric shock
ISO 3864, No. B.3.1 Caution

15
3.5 Electrical installation
The various standard wiring options are shown in gure 1, below. Your controller will arrive from the factory pre-
wired or ready for hardwiring. Depending on your conguration of controller options, you may be required to hard-
wire some or all of the input/output devices. Refer to gures 6 through 18 for circuit board layout and wiring.
Note: when wiring the optional ow meter contactor input, the 4-20 mA outputs or a remote ow switch, it is advis-
able to use stranded, twisted, shielded pair wire between 22-26 AWG. Shield should be terminated at the controller at
the most convenient shield terminal.
CAUTION
1. There are live circuits inside the controller even when the power switch on the front panel is in the OFF posi-
tion! The front panel must never be opened before power to the controller is REMOVED!
If your controller is prewired, it is supplied with an 8 foot, 14 AWG power cord with NEMA 5-15P USA style
plug. A tool (#2 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 applica-
ble 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 specied by Walchem may impair the protection provided by the equip-
ment.