WDT

OverviewWalchem’s WDT300/310 Series controllers feature dual input channelsfor use in conductivity control of cooling towers. Input signals,depending on system configuration, are conductivity and either pH orORP. WDT300 offers conductivity control of two cooling towers. Outputrelays activate system bleed and chemical feed for each tower. WDT310 offers conductivity control of one tower with inhibitor feed,two biocide feeds, plus either pH or ORP control. High and low setpoints, adjustable deadband and up to two optional isolated 4-20 mAoutputs are available for conductivity and pH/ORP measurements.The WDT Series controllers provide full input channel signal isolationto eliminate the possibility of ground loops and electrical interference. The pH/ORP electrode employs a differential measurement techniquethat resists electrical noise. The WDT Series controller ensures ulti-mate reliability and accuracy.WDT SeriesDual InputCooling Tower ControllersSummary of BenefitsFour Chemical Feed Options:Feed-bleed simultaneously- with/without feed lockout timerFeed after bleed has finished- as a percentage of bleed timeFeed as a percentage of time elapsedFeed as a percentage of make-up waterTimed sample conductivity control. Intermittent rather than con-tinuous sampling reduces installation costs on evaporative coolerapplications or small cooling towers.Contact divider accumulates up to 100 pulses, accommodating awide range of water meters.WDT300 SeriesFeed & Bleed Cooling Tower Controller The WDT310 Series offers all of the WDT300 features as well as:Programmable biocide additions:Choice of 1, 7, 14, or 28-day cycles.Able to: add a single biocide at any time ordual alternating biocides ordual independent biocidesAlso able to add a biocide up to 10 times a day. Ideal forbromination or towers with small volumes and large makeupdemand.Bleed lockout timer. Prevents waste of chemistry by preventingblowdown immediately after a biocide addition.Conductivity based biocide prebleeds. Ensures acceptable conductivity level prior to a biocide addition and lockout and is userprogrammable.Flow totalizer. If feeding is based on water meter/contactor, thevolume of make-up water will be totalized. Especially important ifthe flow meter is inaccessible.WDT310 SeriesFeed & Bleed Cooling Tower Controller with Biocide AdditionsFour chemical feed optionsFeed & bleed, with or without feed lockout timerFeed after bleed has finished, as a percentage of timeFeed as a percentage of time elapsedFeed as a percentage of make-up waterContact divider accumulates up to 100 pulses.Accomodates a wide range of water meters.Timed sample conductivity control. Intermittent samplingreduces installation costs on evaporative cooler applicationsor small cooling towers.Direct or inverse set point operation. For applications thatrequire reverse set point capability, such as a closed loopchilled water cooler. Programmed via easy menu option, direc-tion is indicated at all times on controller parameter displays.Self-Diagnostics. Software, electronics and sensor are con-stantly monitored without having to take the controller offline. Any error messages are displayed.Programmable access code. Secures set point parameters.Program any four digit access number or disable the coderequirement.HOA output modes. Each output may be set to run by hand,automatically, or be shut off.Extended CapabilitiesConductivity electrodes are available in several mounting styles and pressure ratings.Optional isolated 4-20mA outputs proportional to the conductivity or pH/ORP reading.Optional integral flow switch.Accessories include flow meters, flow switches, solenoid valves, chart recorders, pumps and tanks.Conductivity Range 0-10,000 µS/cmResolution 1 µSAccuracy 10-10,000 µS/cm ±1% of reading0-10 µS/cm ±20% of readingTemperature Range 32 to 158°F ( 0 to 70°C)ResolutionAccuracy0.1 degree±1% of readingpH Range -2 to 16 pH unitspH Response 95% in less than 5 secondsImpedance (cartridge) not to exceed 1000M?(housing) 100 ohms, preamplified versionsnot to exceed 1000 M?, non-preamplifiedTemperature Range 50-158°F (10-70°C)MEASUREMENT PERFORMANCEEnclosure FiberglassNEMA rating NEMA 4X (IP65)Display 2 x 16 character backlit liquid crystalAmbient temperature 32 to 158°F (0 to 70°C)Shipping weight 7 lbs (3 kg) (approximately)MECHANICAL (controller)INPUTSPower 110-120 VAC 220-240 VAC50/60 Hz, 10A 50/60 HZ, 5ASignals Conductivity 1.0 cell constant10K thermistorpH/ORP* Requires a preamplified signalWalchem’s WEL electrode recommended± 5V available for external preampsFlow Meter Isolated, dry contact closure required (relay, reed switch or Hall (optional) Effect)Flow Switch Isolated, dry contact closure required (reed switch)(optional)*Note: Temperature compensation for the pH input is accomplished using theconductivity electrode 10K thermistor. ORP measurement does not use temper-ature compensation.OUTPUTSMechanical @ 120 VAC, 10A resistive, 1/8 HPRelays (5) @ 240 VAC, 6A resistive, 1/8 HPFor WDT300: Bleed & feed relays for each towerand diagnostic alarmFor WDT310: Bleed, feed, biocide #1, biocide #2 and pH/ORP relay (no diagnostic alarm)4-20mA Fully isolated, internally powered 600?(optional) max. resistive load. Resolution 0.001% of span, accuracy ± 1% of readingProcess connections 3/4” NPTFTemperature 140°F (60°C)Materials of construction PressureGraphite cond. electrode GFRPP, Graphite, FKM 150 psiHigh pressure electrode 316SS, PVDF 300 psiFlow switch manifold GFRPP, PVC, Isoplast, FKM 150 psiPP/Stainless steel electrode GFRPP, 316SS, FKM 150 psipH/ORP electrode CPVC, Glass, Titanium, FKM 100 psiFLOW SWITCH MANIFOLD & SENSORSPECIFICATIONSSpecificationsFLOWFLOWSWITCHSAMPLEVALVE1/4" POLYPROPANEL 19" X 24"BIO-1BIO-2¾“ NPTF¾“ NPTFFLOWCONDUCTIVITYELECTRODEWEL pH/ORPELECTRODEpHPWR115/230J-Box22 ½"17½"CHEMFEEDBLEED24”19”Ordering Information(Voltage) (Output) (Electrode)WDT300 - or WDT310 VOLTAGE OUTPUT1 = 120 VAC, prewired N = No 4-20 mA output 4 = 120 VAC, conduit 4 = Single 4-20 mA output5 = 240 VAC, conduit 2 = Dual 4-20 mA outputsELECTRODES - WDT300N = No electrode1 = 2 graphite electrodes & tees (in-line or submersion), 20ft cables2 = 2 graphite electrodes & flow switch manifolds, no PP panel, 20ft cables4 = 2 high pressure electrodes & glands, 10 ft cables5 = 2 high pressure electrodes & flow switch manifolds, 20 ft cables6 = 2 SS electrodes & tees, 20 ft cables7 = 2 SS electrodes & flow switch manifolds, no PP panel, 20 ft cablesELECTRODES - WDT310N = No electrode1 = SS electrode + pH electrode & tees (in-line or submersion), 20 ft cables2 = SS electrode + ORP electrode & tees (in-line or submersion), 20 ft cables3 = SS electrode + pH electrode & flow switch manifold on PP panel,5 ft cables4 = SS electrode + ORP electrode & flow switch manifold on PP panel, 5 ft cables6 = Graphite electrode + pH electrode & tees (in-line or submersion), 20 ft cables7 = Graphite electrode + ORP electrode & tees (in-line or submersion), 20 ft cables7R= Graphite electrode + ORP rod style electrode & tees (in-line or submersion), 20 ft cables8 = Graphite electrode + pH electrode & flow switch manifold on PP panel, 5 ft cables9 = Graphite electrode + ORP electrode & flow switch manifold on PPpanel, 5 ft cables9R= Graphite electrode + ORP rod style electrode & flow switch manifold on PP panel, 5 ft cablesA = High pressure electrodes (Cond + pH) & flow switch manifold on PPpanel, 5 ft cablesB = High pressure electrodes (Cond + ORP) & flow switch manifold on PPpanel, 5 ft cablesWalchem designs and manufactures an integratedline of analytical control,sensing and feed devices. Our in-house engineering isdriven by quality, technologyand innovation. For more information on theentire Walchem product line,visit : www.walchem.comWalchem Corporation Five Boynton Road Hopping Brook Park Holliston, MA 01746 USA www.walchem.com Phone: 508-429-1110 Fax: 508-429-7433P/N 180161.F 3/27/06AGENCY CERTIFICATIONSUL 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.*Equipment suitable for use in establishments other than domestic, andthose directly connected to a low voltage (100-240 VAC) power supply network which supplies buildings used for domestic purposes.WEBMASTER GENERALINDUSTRIAL CONTROLLERWEBMASTER COOLING TOWERAND BOILER CONTROLLERMETERING PUMPS ANDACCESSORIESWEBALERT REMOTEMONITORING & DATALOGGING