Walchem WDB400 Series User manual

WDB400 Series
Dual Boiler Controller
Instruction Manual
Walchem Corporation Five Boynton Road Hopping Brook Park Holliston, MA 01746 USA
TEL: [phone] FAX: [phone] WEB: www.walchem.com
W A L C H E M
W
DB400 Controllers

Notice
© 2008 WALCHEM Corporation
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 Corporation. 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 Corporation, 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 Corporation 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 Corporation and for the purposes disclosed in writing at
the time of purchase, if any. WALCHEM Corporation'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 Corporation, transportation charges prepaid, has been inspected and
determined by WALCHEM Corporation 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.
180328.D
Jul 2008

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 WDB 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...................................................................................................................8
3.5 Electrical installation...........................................................................................................8
4.0 FUNCTION OVERVIEW ......................................................................................................12
4.1 Front Panel.......................................................................................................................12
4.2 Display..............................................................................................................................12
4.3 Keypad .............................................................................................................................13
4.4 Access Code ....................................................................................................................13
4.5 Startup..............................................................................................................................13
4.6 Shut Down........................................................................................................................13
5.0 OPERATION........................................................................................................................14
5.1 Main Menu........................................................................................................................14
5.2 Conductivity (A or B) Menu...............................................................................................16
5.3 Temperature (A or B) Menu.............................................................................................18
5.4 Blowdown (A or B) Menu..................................................................................................19
5.5 Auxiliary Menu..................................................................................................................21
5.6 Time Menu........................................................................................................................24
5.7 4-20mA (A or B) Menu......................................................................................................25
5.8 Access Code Menu ..........................................................................................................26
5.9 Datalog Menu...................................................................................................................27
5.10 Config Menu.....................................................................................................................29
5.11 Upgrade Menu .................................................................................................................30
6.0 MAINTENANCE...................................................................................................................31
6.1 Electrode Cleaning ...........................................................................................................31
6.2 Replacing the Fuses.........................................................................................................31
7.0 TROUBLESHOOTING.........................................................................................................32
7.1 Error Messages................................................................................................................32
7.2 Conductivity Readout Does Not Change..........................................................................34
7.3 Procedure for Evaluation of Conductivity Electrode.........................................................34
7.4 Procedure for Checking Relay Outputs............................................................................34
7.5 No Display........................................................................................................................35
8.0 SERVICE POLICY ...............................................................................................................35

1
1.0 INTRODUCTION
The Walchem WDB400 Series controllers offer conductivity control of boiler water and control of
chemical feed of two separate boilers. The chemical feed pump may be selected to operate in one of the
following modes:
Feed and Blowdown
Feed and Blowdown with Lockout
Feed as a percent of Blowdown
Feed as a percent of Time
Feed based on a Water Contactor input
The WDB series boiler controller is supplied with temperature compensated stainless steel electrodes with
a cell constant of 1.0. The controller is a microprocessor driven industrial type with on/off control
outputs. Timed intermittent sample or continuous modes may be selected. One or two optional 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.
An alarm relay is provided that is triggered by:
Low conductivity reading
High conductivity reading
No flow situation
Sensor error
Temperature sensor error
Blowdown timeout
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
months readings and events to a USB flash disk.

2
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 - 392°F (0 - 200°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 constant, Pt1000 RTD
Flow Meter (optional) Isolated, dry contact closure required (i.e. relay,reed switch)
Flow Switch (optional) Isolated, dry contact closure required (i.e. reed switch)
Outputs
Mechanical Relays 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 (1 or 2 optional) Internally powered
Fully isolated
600 Ohm max resistive load
Resolution .001% of span
Accuracy ± 1% of reading
Agency Approvals
UL ANSI/UL 61010-1:2004, 2nd Edition*
CAN/CSA C22,2 No.61010-1:2004 2nd Edition*
CE Safety EN 61010-1 2nd Edition (2001)*
CE EMC EN 61326 :1998 Annex A*
Note: For EN61000-4-6,-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)
Electrode mounting ¾" NPTF
Electrode rating 250 psi at 392°F (17.2 bars at 200°C)
Electrode material 316 SS and PEEK

3
2.4 WDB 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
Hold Time 1 second 499 min: 59 sec
Blowdown Time 1 minute 8 hrs: 20 min
Max Proportional Time 1 minute 8 hrs: 20 min
Proportional Band 0 10,000 µS/cm
% Calibration Range -50% +50%
Temperature Menu No variables
BlowdownMenu
Set Point 0 µS/cm 10,000 µS/cm
Dead Band 5 µS/cm 500 µS/cm
Blowdown 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 Blowdownd (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
Divider Count (Mode D) 1 contact 100 contacts
Feed Time Accumulate (Mode D) 1 minute 99 min: 59 sec
Time Limit (Mode D) 1 minute 99 min: 59 sec
4-20 mA Menu 4 & 20 mA Settings 0 µS/cm 10,000 µS/cm
Access Code Menu New Value 0 9999
Alarm 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.

4
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 WDB series controller and instruction manual. Any options or accessories will be incorporated
as ordered.
3.2 Mounting the electronic enclosure
The WDB 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 WDB 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. Less than 25 ft is recommended. The cable MUST be shielded from
background electrical noise. (The standard cable length is 10 feet. Should you require longer cable,
consult factory.)
Important Installation Notes: (see figure 1)
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 flow restrictions from the tap for the boiler
skimmer blowdown line to the electrode. If the ID is reduced below 3/4 inch, then flashing 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 off 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 flow restriction.
4. Keep the distance between the tap for the boiler skimmer line to the electrode as short as
possible, to a maximum of 10 feet.

5
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 flow restriction after the electrode and/or control valve in order to provide
back pressure. This flow restriction will be either a flow control valve or an orifice union. The
amount of the flow restriction will affect the blowdown rate as well, and should be sized
accordingly.
7. Install the motorized ball valve or solenoid valve per the manufacturer’s instructions.
8. For best results, align the hole in the conductivity electrode such that the direction of water flow
is through the hole.
Guide to Sizing Blowdown Valves and Orifice Plates
1. Determine the Rate of Steam Production in Pounds per Hour
Either read off the boiler name plate (water-tube boilers) or
Calculate from horsepower rating (fire-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 flow control valve or less than the flow
through the smallest orifice. See the charts below.
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 flow control valve or orifice. See the charts below.
Use of a flow control valve will give you the best control of the process, since the flow rate can be easily
adjusted. The dial on the valve also gives you a visual indication if the flow rate has been changed. If the
valve clogs, it can be opened to clear the obstruction, and closed to the previous position.
If an orifice plate is used, you must install a valve downstream from the orifice in order to fine tune the
flow 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 flow rate of
the smallest flow control valve is 3250 lbs./hr. 3250 x 0.25 = 812.5 which is too high for continuous
sampling. Using an orifice, the flow rate through the smallest diameter plate is 1275 lbs./hr. This is too
high for continuous sampling.

6
5. Determine the Orifice or Flow Control Valve Size for this Blowdown Rate
Use the following graphs to select a flow control device:
Flow Rate in Lbs/hr for VariousOrifices
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
10 20 30 40 50 60 70 80 90 100 200 300
Pressure PSI
Lbs/hr
1/8 inch dia
3/16 inch dia
1/4 inch dia
5/16 inch dia
Flow Control Valve
Maximum Flow Rates in Lbs/hr
0
5000
10000
15000
20000
25000
20 30 40 50 60 70 80 90 100 150 200 300
Pressure PSI
Lbs/hr
1/2" 150 PSI
1/2" 300 PSI
3/4" 150 PSI
3/4" 300 PSI

7
FI
G
URE 1
RECOMMENDED INSTALLATION
INTERMITTENT SAMPLING
Install accessories
either vertically or
horizontally, per
manufacturer's
instructions.
To Drain
Skimmer Blowdown Line
3/4" Min. up to Electrode
Full Port Block
Valve
Manual Blowdown
(Normally Closed)
Motorized
Ball
or Solenoid
Valve
Flow
Control
Valve or
Orifice Union
CONDUCTIVITY
ELECTRODE
¾" TEE
2 ft.
minimum 1 to 3 ft. maximum
10 ft. max.
with minimal valves, elbows & unions
To Drain
Skimmer Blowdown Line
3/4" Min. up to Electrode
Full Port Block
Valve
Manual Blowdown
(Normally Closed)
Motorized
Ball
or
Solenoid
Valve
Flow
Control
Valve
or Orifice
Union
CONDUCTIVITY
ELECTRODE
¾" TEE
Flow
Control
Valve or
Orifice Union
FIGURE 2
RECOMMENDED INSTALLATION
CO
NTIN
UOUS
S
AMPLIN
G
TO
DRAIN
To Drain
To Drain
Boiler Controller
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