Troubleshooting WCT/ WBL 300/400 series controllers
Serial number guide
Unit will not power up
No display
Pump or other device connected to relay will not turn on
Controller fails conductivity self-test
Controller registers contact from water meter with no flow
Controller fails pH/ORP self-test
Relay troubleshooting
Controller doesn't register flow from the water meter
 
1. Serial number guide:
For serial numbers prior to the end of 1999, there is a 6 digit format. The first two numbers are the month (06 is June, 10 is October), the third digit is the year (8 is 1998), and the last three digits are sequential (308 is the three hundred and eighth controller built in that month). Certain cooling tower and boiler controllers begin with a letter V to indicate that they were built with a new style enclosure. This is important to know so that if we send a replacement front panel it will fit correctly. Starting at the end of 1999, we went to a 10 digit format, such as 991109xxxx, where the first two digits are the year, the next two are the month, the next two are the day, and the last four are sequential. (Top)

 2. Unit won't power up:
CAUSE: F1 fuse is blown, due to a power surge or lightning strike.Verify that the fuse is blown by removing fuse and checking for continuity from end to end using an ohmmeter. Replace F1 fuse, part number 102369. If the unit is still dead, and the fuse is still intact then other components have been damaged. The most common components to be damaged by a power surge are MOV 1 and 2. If the problem occurs repeatedly, install a surge suppressor on the power source, or locate a cleaner source of power to use.

CAUSE: F1 fuse is blown, due to a faulty component in the controller. Fuse immediately blows when replaced.Remove all option boards and sensors. If the fuse blows, the problem is within the controller, most likely the front panel assembly. Try replacing it. If the fuse survives, add option boards one at a time, restore power, and see if the fuse still survives. The part which when connected causes the fuse to blow is faulty, and should be replaced. (Top)

 3. No display:
CAUSE: Improper installation of the 4-20 mA option board. This cannot happen at the factory, since the units are tested after installation of an option board.If the option board is installed onto its connector, but is off by one pin, the display will not come up. Remove the option board and reinstall it correctly.

CAUSE: Ribbon cable installed backwards. This problem cannot happen at the factory since the units are tested prior to shipment.Install the ribbon cable between the power supply board and the front panel assembly correctly. Refer to the drawing in the installation section of the instruction manual.

CAUSE: Installation ambient temperature is higher than specified. This is likely if the display seems to be completely black.Install controller where the ambient temperature will not exceed 70 degrees C (158 degrees F).

CAUSE: Defective solder joint. Especially prevalent for controllers built before 1998.
If you can see a poor connection between the display circuit board and the processor board, and you are capable, you can try to touch up the solder joint. If you are unable to fix it, order a replacement front panel assembly (refer to the price list for the appropriate part number). Keep in mind that any attempts to do component-level repairs will void your warranty.

CAUSE (for WBL controllers only) Software bug. If the display is lit in other menus but not in the top level menu, the problem is caused by a bug in the software where the top level display is not updated once a blowdown time limit error occurs.
Reset the display by cycling the power off and back on again. Troubleshoot the reason for the blowdown time limit error to have occurred. (Top)

 4. Pump or other device connected to relay will not turn on:
CAUSE: F2 fuse is blown. Remove F2 fuse and measure from end to end with an ohmmeter to verify fuse is blown. (Note: the WPH320, WDP320 and WDP340 controllers do not have a F2 fuse, since all outputs are either pulse or dry contact relays.)
Replace the F2 fuse (part number 102432 if 115 V unit, 102370 if 230 V unit), and disconnect all devices from the controller. If the fuse blows again, there is a problem internal to the controller. If not, then connect one device at a time to determine if the device is drawing too much current and is causing the fuse to blow.

CAUSE: Faulty relay. Verify that the relay is faulty by forcing the relay closed (using the Manual Output feature for W300 series, or adjusting the set point for W-130/230). Remove the terminal block and measure across the pins using an ohmmeter. If the meter does not indicate a connection, the relay is faulty. Make sure that you compare the terminal block position as pictured in the instruction manual with its actual position. It is possible to place the terminal in the wrong location, so that the relay that is closing is not corresponding to the pins you are checking.
If you can do component level troubleshooting, replace the part number 102329 relay. If not, replace the power supply board.

CAUSE: Faulty connections. If you have checked the relay and know that it is closing, and has power supplied to it (see above) then the problem must be poor connections. With the terminal block in place, force the relay closed and check for continuity between the two terminals using an ohmmeter.
If there is no connection, the terminal block is not making a good connection with the pins. Make sure that you compare the terminal block position as pictured in the instruction manual with its actual position. It is possible to place the terminal in the wrong location, so that the relay that is closing is not corresponding to the pins you are checking. Check all wiring connections. If the relay is powered, make sure that both the Hot and Neutral wires are secure. If using prewired pigtails, if you have voltage at the terminal strip, but not at he end of the pigtail, then the pigtail may have a broken wire or corroded connection. Correct wiring connections.

CAUSE: Faulty power supply board.
Replace power supply board. (Top)

 5. Controller fails conductivity self-test:
CAUSE: Extended Cable. The self test should read 1000 ± 20. If the cable between the electrode and the controller has been extended, expect the self test to decrease by 1 for each foot (0.3 meter) of additional cable over the standard 10 feet (3 meters). If the cable is extended to 500 feet, then the limit of the calibration has been reached (± 50% of the factory calibration value). Any coating on the electrode can drop the conductivity further, causing a calibration failure.
Move the electrode closer to the controller.

CAUSE: Faulty Electrode. While the self test normally isolates the controller from the electrode, there are ways for the electrode to fail that will cause the self test to be too low. Disconnect the electrode from the controller and repeat the self test. If it now passes, the electrode is faulty.
Replace electrode.

CAUSE: Interference from AC coupling on water meter cable. We have seen instances where the water meter cable is routed through the same conduit as AC voltage. If the water meter cable is unshielded (and sometimes even if it is shielded) it can pick up a voltage from the nearby AC wires. This can cause false contacts, set points changing, or self test failure. Disconnect the water meter cable, and try the self test again. If the self test now passes, route the water meter cable separated from any wires carrying AC voltage.

CAUSE: Poor connection of option board to processor board. If the problem is with Sensor B of a dual input model, check the connection between the option board and the processor board. Remove power to the controller. Remove the three screws that attach the option board. If the board seems loose on the connector, the only way to tighten it up is to put a small ball of solder on each of the pins on the connector. The other option is to replace the 190820 option board.

CAUSE: Faulty circuit board. If the problem is with a single input controller, or with Sensor A of a dual input controller, the processor board is faulty. If the problem is with Sensor B of a dual input model, the input option board is faulty. Component level rework of these circuit boards is not recommended.
Replace faulty circuit board. (Top)

 6. Controller registers contact from water meter with no flow:
CAUSE: Interference from AC coupling on water meter cable. We have seen instances where the water meter cable is routed through the same conduit as AC voltage. If the water meter cable is unshielded (and sometimes even if it is shielded) it can pick up a voltage from the nearby AC wires. This can cause false contacts, set points changing, or self test failure.
Disconnect the water meter cable from the controller (not from the water meter), and see if the false contacts stop. If they do stop, route the water meter cable separated from any wires carrying AC voltage. (Top)

 7. Controller fails pH/ORP self-test:
CAUSE: Short on front panel between circuit common and earth ground (the front panel itself). If the bezel of the display is touching the front panel, or legs of any components, then the self test will fail. In older units, accumulations of dust between the processor board or display and the aluminum front panel can cause this problem.
Eliminate the cause of the short, or replace the front panel assembly.

CAUSE: Failure of the electrode. Leakage of water inside the pH/ORP housing can cause the self test to be very low or fail. Inside the electrode, a short between circuit common and earth ground is developed. Verify this by repeating the self test with the electrode wires disconnected from the controller. If the self test now passes, then the electrode or its cable is causing the problem.
Replace the pH/ORP electrode housing (not cartridge).

CAUSE: Interference from AC coupling on water meter cable. We have seen instances where the water meter cable is routed through the same conduit as AC voltage. If the water meter cable is unshielded (and sometimes even if it is shielded) it can pick up a voltage from the nearby AC wires. This can cause false contacts, set points changing, or self test failure.
Disconnect the water meter cable, and try the self test again. If the self test now passes, route the water meter cable separated from any wires carrying AC voltage.

CAUSE: Poor connection of option board to processor board. If the problem is with Sensor B of a dual input model, check the connection between the option board and the processor board.
Remove power to the controller. Remove the three screws that attach the option board. If the board seems loose on the connector, the only way to tighten it up is to put a small ball of solder on each of the pins on the connector. The other option is to replace the option board.

CAUSE: Faulty circuit board. If the problem is with a single input controller, or with Sensor A of a dual input controller, the processor board is faulty. If the problem is with Sensor B of a dual input model, the input option board is faulty. Component level rework of these circuit boards is not recommended.
Replace faulty circuit board. (Top)

 7. Relay troubleshooting:
Start at the device (pump, valve, etc.) and work back towards the relay. With the output in question activated:
1. Manually cycle the output on and off. If you not hear the relay click open and closed (assuming you are in a quiet location!) skip to 9 below, otherwise:

2. Check F2 fuse (if present; not needed for WPH320, WDP320 or WDP340 controllers) by measuring voltage between Neutral and both ends of the fuse. If voltage is present at the bottom of the fuse, but not present at the top of the fuse, it is blown and needs to be replaced. Look for any obviously burned circuits or components.  If a fuse continuously blows, then a device attached is drawing too much amperage. Note that motors draw 3-4 times more current at startup than the rated current. The limit for motors is 1/8 HP.

3. Check for voltage at the device. If present, the device is defective. If not present:

4. Check for voltage at the terminal strip (between Neutral terminal and the NO terminal of the active output). If present, the wiring between the terminal strip and the device is defective. If not present:

5. Check that the terminal strip is installed in the correct location as compared to the instruction manual. If correct:

6. Check to see if the Neutral wire of the device is connected correctly. If correct:

7. Check to see if the relay is internally powered or dry contact. A powered relay will be labeled NO (or both NO and NC for the one furthest to the right) while a dry contact will be NO and COM. If it is a dry contact, verify that voltage is supplied to the COM terminal. If OK:

8. Remove the terminal block and check for voltage between Neutral and the pin that the terminal block connects to. If present, the terminal block connection is poor or the terminal block is defective. If not present:

9. Measure DC voltage on IC U2 between pin 8 (ground) and pin 1 (for K1 relay), or pin 2 (for K2 relay) …or pin 5 (for K5 relay). The IC may be partially hidden by the 4-20 mA option board. Remove the option board before taking measurements. You should see 5 VDC when the output is active, and 0 VDC when output is off. If not, the ribbon cable is probably defective. If OK:

10. Measure DC voltage on IC U2 between pin 8 and pin 16 (for K1 relay) or pin 15 (for K2 relay) … or pin 12 (for K5 relay). This should be 0.7 VDC when the output is active, and 9 VDC when output is off. If not, then the IC U2 is defective. If OK:

11. Relay is defective. (Top)

 8. Controller does not register flow from the water meter:
CAUSE: The controller input if faulty. Test this by removing the water meter cable from the controller terminal strip and repeatedly shorting the input and removing the short. If the controller does not register the contacts, it is faulty.
Replace the label/panel assembly.

CAUSE: The water meter cable is faulty. If the controller input tests OK, then connect the water meter cable and try to short the opposite end of the cable. If the controller registers flow, the cable if OK.
Replace the cable.

CAUSE: There is no water flow.
Look for closed valves, verify that there is flow through the makeup line. Restore flow.

CAUSE: Water meter is faulty.
Replace water meter. (Top)
 
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