Walchem WDT400 Series Instruction Manual

Walchem WDT400 Series Instruction Manual Manual pdf 32 page image

6.2 Replacing the FusesCAUTION: Disconnect power to the controller before opening front panel!Locate the fuses on the circuit board at the back of the controller enclosure. (See figure 3.) Gentlyremove the old fuse from its retaining clip and discard. Press the new fuse into the clip, secure the frontpanel of the controller and return power to the unit.Warning: Use of non-approved fuses can affect product safety approvals. Fuse ratings depend oncontroller power rating. Specifications are shown below. To insure product safety certifications aremaintained, it is recommended that a Walchem fuse is used.F1 Fuse Walchem P/N F2 Fuse Walchem P/N5 x 20 mm, 1.0A, 250V 103163 5 x 20 mm, 6A, 250V 1028347.0 TROUBLESHOOTINGCAUTION: Disconnect power to the controller before opening front panel!Troubleshooting and repair of a malfunctioning controller should only be attempted by qualifiedpersonnel using caution to ensure safety and limit unnecessary further damage. Contact the factory.7.1 Error MessagesHIGH ALARM - (main summary screen only)The summary screen will display an H at the right end of the bar graph if the conductivity rises above the high conductivity alarm setpoint. If your unit is wired for alarm output, the alarm relay will trip. The controller will continue to check the conductivity, and thebleed and/or feed outputs will be allowed to be activated.Possible Cause Corrective ActionDirty electrode Clean electrode (see Sect. 6.1)Faulty solenoid valve Repair or replace solenoid valve.Faulty electrode Evaluate (see Sect. 7.3). Check Temp display.Improper wiring of valve or controller Correct wiring. (see Section 3.4)Faulty bleed relay Replace relay. (Consult factory.)Conductivity rose over alarm limit while biocideoccurred. Allow normal bleed to occur.Clogged Y-strainer in bleed line. Clean Y-strainer.LOW ALARMThe summary screen will display an L at the left end of the bar graph and the alarm relay will trip. The controller will continue to checkthe conductivity and feed inhibitor as programmed.Possible Cause Corrective ActionSensor disconnected Reconnect. Check cable for continuity.Sensor dry Check tee for obstruction. Verify flow. Change location of electrode.Solenoid valve stuck open Repair or replace solenoid valve. (Consult your distributor).Faulty electrode Evaluate (see Section 7.3). Replace if necessary.Improper wiring of electrode Correct wiring. (see Section 3.4)Faulty bleed relay Replace relay. (Consult factory.)Pre-bleed set too low. Check pre-bleed setting compared to % low.29