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1.
Will my controller be safe from hackers?
In
order to access your controller, a competitor would need
to have a valid user name and password to use our utility,
know the phone number for the controller, and also know
the access codes for the controller. The controller is
only on the web when you tell it to go there and the IP
address for the controller changes every time it gets
on. Unauthorized access is extremely unlikely!
2.
Will the Controller give a hacker access to my LAN?
Even
if an unauthorized user managed to access the controller,
the WebMaster® is not a PC, so it is unlikely that it
could be used to get into the LAN. You can also connect
the controller outside the firewall. There are many options
available for a safe installation. We can provide a diagram
that shows these options, which is useful to show your
customer's IT Administrator.
3.
Can
I network WebMaster®s together?
Only
by utilizing the Ethernet feature. We plan on adding a
RS485 feature in the near future.
4.
What
are the minimum requirements for my PC to communicate
with the WebMaster®?
You
need to have a computer with enough speed and RAM to comfortably
surf the Internet. We recommend a processor speed of 100
MHz and 40 MB RAM. The operating system must be Microsoft
Windows. The browser software needs to be Microsoft Internet
Explorer version 5.0 or above.
5.
How does the WebMaster® get onto the Internet?
Either
you utilize the Ethernet option to have a permanent IP
address, or you set up a dialup account with a local Internet
Service Provider. Multiple controllers can often use one
account. Walchem can assist in recommending reliable ISPs.
If the ISP requires custom software (like AOL), or if
it is a free service that relies on advertisements, then
it will not work correctly.
6. Will
I need to put proprietary software
on my computer in order to communicate with the WebMaster®?
No.
All you need is your web browser, Internet Explorer
5.0 or higher.
Everything you need resides on the WebMaster® itself.
As such, you can access a unit from literally anywhere
in the world where you have Internet access.
7. What
about software upgrades, how will I know of enhancements
to the WebMaster®?
No
problem, every time you access your WebMaster® over the
Internet it checks to see if a software upgrade is available.
If one is, a menu selection for software upgrade
is highlighted.
You can immediately perform the upgrade, or read
what the upgrade includes to see if you really need it.
The choice is yours.
If you do perform the upgrade, the WebMaster® suspends
it functions until the upgrade is complete.
All you need to do is reset the system and you
are back in business because your settings are never lost.
8.
What
happens if I forget my access code?
If
you are at the WebMaster® installation location, you can
press certain keys to show you the access code.
Access is as secure as the controller’s location.
The enclosure can be pad locked for additional
security.
9.
How
does ShoulderTap® work?
We
could tell you, but then we’d have to kill you.
10.
In
the future, I will want to utilize more of the features
available with a WebMaster®.
Can I add features or options in the field?
Yes.
The WebMaster® was designed with modularity in
mind.
Additional sensor boards can be easily added in
the field.
The 4-20 mA inputs and outputs and the digital
inputs are also plug-in circuit boards.
Even the modem and Ethernet options are plug-ins.
Once installed, your WebMaster® will recognize
that they are present and you will see them listed on
the menu, all that’s left is for you to program.
1.
How do I add 4-20mA output to my W300 series controller?
W300 controllers can be ordered with a 4-20mA option board
factory installed by specifying it in the model code.
This option board (p/n190744) can also be installed in
the field by simply plugging it into a header. With the
exception of a screwdriver used to open the front panel,
no tools are required to actually install the board.
The separate option board
(p/n 190744) may be installed in the field by plugging
into the connector on either the power supply board and/or
the front panel board. The instruction manual for your
particular controller will provide the details on where
the option board may be installed. When the controller
is powered up again, the menus for the 4-20 mA output
will appear.
CAUTION: There are live
circuits inside the controller even when the power switch
on the front panel is turned OFF. The front panel should
never be opened before power to the controller is REMOVED.
2.
How do I convert the voltage on my W300 series controller?
There is a switch located next to the transformer labeled
either "115 V" or "230 V". With power removed from the
controller, flip the switch to the appropriate position.
The fuse labeled F2 will need to be changed to the correct
version for the new voltage. See your instruction manual
for part numbers. Note that only these specific fuses
can be used while maintaining the UL, CSA and CE approvals.
(There is no F2 fuse for WPH320, WDP320 or WDP340 series
controllers, since the power for all control outputs is
supplied by an external source).
CAUTION: There are live circuits inside the controller
even when the power switch on the front panel is turned
OFF. The front panel should never be opened before power
to the controller is REMOVED.
3.
Why does the controller overshoot the set point?
A. Pump is too large: Calculate
the flow rate required. The metering pump should be set
for no more than 1.5 times the expected depletion rate
of the chemical. Either adjust the flow rate of the pump
down to this level, or replace the pump with one that
better matches the required flow rate.
B. Pump is siphoning: Install
anti-siphon valve on metering pump, or on metering pump
discharge line. Avoid "down hill" tubing runs. A metering
pump injecting into open atmosphere can pump more than
its rated capacity if an injection check valve is not
installed.
C. Poor mixing/large lag
time: Improve mixing, or move the location of the sensor
and/or replenishment so that chemical additions reach
the sensor faster. If using a flow-through sensor, make
sure that the flow rate through the sampling system is
sufficient (less than 1 minute to detect additions).
If the lag time can’t be improved, then in pH/ORP applications,
a proportional controller should be used. For other applications,
it may be possible to use the optional 4-20 mA output
for proportional control.
D. Fouled sensor: If the
response time of the sensor to a step change in concentration
is slow, then the sensor may need to be cleaned, calibrated
or replaced. Follow the sensor troubleshooting instructions
for that particular sensor.
E. Programmed incorrectly:
For on/off controllers, make sure the value of the dead
band menu is not too large. For proportional controllers,
increase the value of the proportional band menu.
F. Relay stuck closed:
Use the "Hand-Off-Auto" menu to control the relay. If
an ohmmeter doesn’t show the contact opening and closing,
then replace the power supply board or have the unit serviced
by the factory.
4.
How far can I run the electrode cable?
For the most reliable installation, the cable length should
be as short as possible. The absolute maximum cable length
is 500 feet.
| WBL
Series Boiler Controllers Frequently
Asked Questions |
1.
Can I use your controller for boilers with pressures exceeding
250 psi?
While our boiler electrodes are rated to 250 psi, they
can be used in higher pressure boilers if a sample cooler
is incorporated into the blowdown skimmer line. This method
of installation is preferred even in lower pressure applications,
since it eliminates potential problems related to flashing,
and improves safety.
2.
How far can I run the electrode cable?
For the most reliable installation, the cable length should
be as short as possible. The absolute maximum cable length
is 500 feet. Proper shielding of the cable is essential
to reliable performance. Four conductor, 24 AWG, shielded
cable should be used.
| WCU/WNI
Series Electroless Copper and Nickel Controllers
Frequently Asked Questions |
1.
Can I use this controller to monitor my waste treatment?
The WCU and WNI controllers are designed to work in metal
bearing solutions of a fairly high concentration. The
lowest we can detect is 10 mg/l and the lowest realistic
set point is 100 mg/l. This is much higher than the levels
typically required for wastewater treatment effluent to
a POTW. The WCU or WNI should not be used for these applications.
Any solution that is not
either electroless nickel, electroless copper, or a copper
microetch may have different optical characteristics,
and our controllers may not function properly, even if
the metal concentration is within our specified range.
Consult the factory for any unusual applications.
2.
How far can I run the electrode cable?
For the most reliable installation, the cable length should
be as short as possible. The absolute maximum cable length
is 80 feet. Walchem cable specifically designed for this
purpose must be used to extend the cable length.
1.
What pH/ORP electrodes
can I use with this controller?
All W300 series controllers that include
a pH or ORP input (WPH series, WDP series or WDT series)
have the following requirements for the electrode signals:
a preamplified electrode signal, a Pt100 or Pt1000 temperature
signal (if automatic temperature compensation is necessary
for your pH application) and the preamplifier must be
powered by ± 5 VDC.
The ideal electrode is
the WEL series. This offers a differential amplifier,
easily replaceable electrode cartridge and optional temperature
signal.
Walchem can provide a preamplifier
that can accept the necessary power, and can connect with
any standard electrode with a BNC connector on the cable.
2.
How far
can I run the electrode cable?
Once the electrode signal is amplified, the cable may
be extended up to 1000 feet (300 meters). If using a standard,
nonamplified electrode connected to a preamplifier, the
electrode should be located as close to the preamplifier
as possible. A maximum of 20 feet is recommended. With
the WEL, the amplifier is right in the electrode, for
maximum reliability. An electrode cable must be routed
away from any AC wiring, fans, motors, or other sources
of electrical noise.
Keep in mind that the pH/ORP electrode will require calibration
on a regular basis. The longer the distance between the
electrode and the controller, the more painful the calibration
procedure will be. At 1000 feet of separation, you will
either need two people with 2-way radios or some good
track shoes.
3.
How long will
my electrode last in my application?
It is difficult to predict pH/ORP electrode
life in certain applications. These electrodes are similar
to batteries, and eventually they will run down. There
are some factors that will influence the life:
Temperature: The higher the temperature, the lower the
life of the electrode. If the electrode is exposed to
temperatures over 140 degrees F (60 degrees C) on a regular
basis, the expected life may only be several months.
Shelf Life: The span of
a pH electrode (the mV that the electrode puts out per
pH unit) will decrease with time, even if the electrode
is stored in the original soaker bottle. Eventually, two
pH buffers will create almost the same mV output, and
the electrode will fail calibration. Walchem electrodes
are warranted to have a 12 month shelf life.
Abrasion: Scratches on
the pH glass will reduce the span of the electrode. Our
flat surface design minimizes this effect.
Chemical Attack: Acid Fluorides
will dissolve the pH sensitive glass. Our HF-resistant
glass option will minimize this effect. An electrode that
might dissolve in a few days with normal pH glass, might
last several months with HF-resistant pH glass. Take careful
notice of all the wetted materials of construction of
an electrode, and make sure that they are compatible with
whatever may be found in your solution.
Contamination of Reference:
The pH/ORP electrode utilizes a silver/silver chloride
reference to measure the process signal against. Certain
chemicals (heavy metals, sulfides, proteins, etc.) will
interact with the silver, and either clog the junction
or dissolve the reference.
Coatings: An application
where the electrode frequently coats will require frequent
cleaning, and this increased handling will result in increased
abrasion, and shorter life. The flat design will reduce
the frequency of cleaning. Our probe wash feature will
decrease the handling required when cleaning.
4.
When should I use proportional control instead of ON/OFF
control?
Proportional control will always provide more accurate
control of your process, but the controller and metering
pumps will be a little more expensive. Here are some guidelines
to determine if you can save the money or not.
On/off control can generally
be used for applications where the response time of the
system to chemical additions is fast, and/or where the
acceptable range of the pH/ORP is wide. In a small, well
mixed tank, on/off control can maintain the pH within
0.1 or so of the set point. In a well designed industrial
wastewater pretreatment system, where there is sufficient
residence time of the water flowing through the tank,
and the acceptable level of pH may be ± 0.5 or more, on/off
control will also be fine.
Use proportional control
whenever there is an extremely tight control range (±
0.1 or less), where there are long delays between adding
the chemical and detecting the addition, or when the set
point is at an infection point in the titration curve
such that when a small addition is made the pH changes
dramatically.
5.
Can I do pH control of water
flowing through a pipe without tanks?
It is possible, but not simple, depending upon the application.
If at all possible, include a tank with a mixer in the
system. The tank should be sized to provide at least 20
minutes of retention time (for example, if the water flow
rate is 20 gallons per minute, use a 400 gallon tank).
If you control the pH on the fly, without a tank, there
are a number of considerations. First, if the flow rate
and the incoming pH are both variables, then you need
to have a pH transmitter and a flow transmitter sending
signals to a PLC, which can integrate these two signals
to determine the flow rate of the metering pump required.
The injection point of the pH adjusting chemicals must
be downstream from the pH electrode. A second pH transmitter
further downstream can provide verification that the pH
is correct.
If flow is constant, then
a proportional pH controller can handle the application,
with set points adjusted such that the pump operates at
the correct speed for the incoming pH. Again, the injection
point must be downstream from the pH electrode.
If the pH needs to be adjusted by more than 2 pH units,
then incorporating a tank is highly recommended.
| W-130/230
Series pH/ORP Controllers Frequently
Asked Questions |
1.
How far can I run the electrode cable?
The W-130 and 230 Series controllers contain
a preamplifier, and can take an unamplified electrode
signal directly into its BNC connector. This cable length
should be kept less than 20 feet. If there is not much
electrical noise or radio interference nearby, this cable
may be longer, but this is not universally reliable.
In order to extend this
cable much farther than 20 feet, the signal may be amplified
by using a part number 102710 battery operated preamplifier.
This requires a part number 190890-xx extension cable,
available in lengths between 50 feet and 125 feet, in
25 foot increments. The "xx" above refers to the cable
length (for example "75").
In general, it is better
to keep the electrode cable as short as possible. If the
electrode is too far away it will make calibration of
the electrode inconvenient.
2.
How do I add a 4-20mA option to my W-130/230 series controller?
This conversion is not possible. You will need to order
a model that includes the 4-20 mA output circuitry.
| WEC300
Series Electrode-less Conductivity
Controllers Frequently
Asked Questions |
1. How do I know if I can use this controller for my chemical
or chemical blend?
First, the chemical that you want to control
needs to be conductive, which means that in water the
chemical will dissociate into ions (like NaOH will dissociate
into Na+ and OH-). Second, the conductivity of the solution
needs to be between 100 µS/cm and 1000 mS/cm. Third, each
chemical has a curve for the conductivity that corresponds
to a given concentration of the chemical. In some cases
this is linear, in others, it is a bell curve. Depending
upon where you plan on operating on that bell curve, automatic
control is possible. Walchem can assist you if we know
the chemical to be controlled and the expected range of
concentrations.
If you have a mixture of chemicals, then we need to look
at the contribution to the total conductivity of each
of the chemicals involved. If the component of interest
is also the most conductive, then automatic control may
be possible (assuming that the concentration is on the
right part of the bell curve). Consult Walchem for any
application like this.
2.
How far can I run the electrode cable?
For the most reliable installation, the
cable length should be as short as possible. The absolute
maximum cable length is 120 feet. Proper shielding of
the cable is critical. Walchem cable designed specifically
for this purpose must be used to extend beyond the standard
20 feet.
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