Sterling SDAA 25-100 Troubleshooting, Introduction, Problem Possible cause Corrective action

Page 49

Chapter 6: Troubleshooting

6-1 Introduction

The utmost in safety precautions should be observed at all times when working on or around the machine and the electrical components. All normal trouble-shooting must be accomplished with the power off, line fuses removed, and with the machine tagged as out of service.

The use of good quality test equipment cannot be over-emphasized when troubleshooting is indicated. Use a good ammeter that can measure at least twice the AC and DC current that can be encountered for the machine. Be sure that the voltmeter has at least minimum impedance of 5,000 OHMS-per-volt on AC and 20,000 OHMS-per-volt on DC scales. Popular combination meters, VOM and VTVM can be selected to provide the necessary functions.

Before making haphazard substitutions and repairs when defective electrical components are malfunctioning, we recommend that you check the associated circuitry and assemblies for other defective devices. It is common to replace the obviously damaged component without actually locating the real cause of the trouble. Such hasty substitutions will only destroy the new component. Refer to wiring diagrams and schematics.

Locating mechanical problems, should they occur, is relatively straightforward. When necessary, refer to the parts catalog section.

 

Problem

 

Possible cause

 

Corrective action

 

 

 

 

 

 

 

 

 

Dirty filter.

 

Clean or replace filter.

 

 

 

Desiccant beds are contaminated

 

Replace desiccant. See Page 42

 

 

 

by material or plasticizer leaking

 

Little or no air coming from

 

 

for more information.

 

into the system.

 

 

 

 

the process delivery tube.

 

Blower overload has tripped.

 

Fix the problem and reset the

 

 

 

 

overload.

 

 

 

 

 

 

 

 

Blower fins filled with dust or

 

Remove blower side plate,

 

 

 

contaminants.

 

clean baffles, replace.

 

 

 

 

 

Stop the dryer.

 

 

 

 

 

If the dryer was connected to

 

 

 

 

 

the drying hopper, check to see

 

 

 

 

 

if the desiccant and process air

 

Suction in delivery tube,

 

Phase is reversed on power drop

 

heater has been contaminated

 

 

 

with resin.

 

pressure from the return tube.

 

coming into the dryer.

 

 

 

 

If so, replace the desiccant and

 

 

 

 

 

 

 

 

 

 

remove any resin carry-over.

 

 

 

 

 

Otherwise, change the phase of

 

 

 

 

 

two legs of the three-phase

 

 

 

 

 

power drop.

Dehumidifying Dryers

Chapter 6: Troubleshooting

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Contents Sdaa 25-100 15-60 cfm Dehumidifying Dryers Shipping Information Table of Contents Maintenance Service Department Sales Department Contract Department How to Use This Manual SafetySafety Symbols Used in this Manual Wear Safety Glasses and Work Gloves General Responsibility ResponsibilityRemember Operator ResponsibilityReporting a Safety Defect Maintenance ResponsibilityDehumidifying Dryers Safety Models Covered in This Manual Functional DescriptionGeneral Description What is desiccant? Standard FeaturesMechanical Features Electrical FeaturesController Features Safety Devices and InterlocksOptions Safety Device Lock-Outs Safety Circuit StandardsFail Safe Operation Uncrating the Equipment InstallationRigging and Placing the Dryer Machine-Mount Dryer Dimensions Floor-Mount Dryer Dimensions Recommended Dryer Lifting Hardware Suggested Lift Rigging for Cart Mounted DryersSuggested Lift Rigging for Machine Mounted Dryers Electrical ConnectionsThree-Phase Models Setup ProceduresChecking for Proper Blower Rotation Making Dryer/Drying Hopper Process Air ConnectionsDrying Hopper Air Trap Considerations Installing Water Lines Hose and Hose ClampOptional Aftercooler Initial Start-up Auto-Tuning the DryerPre-Startup Checks Starting Up the DryerShutting Down the Dryer Start-up OperationIndicator Lights SwitchesController Description and Operation Lit when Control Output 1 is on. The Out1 Process Air Temperature ControllerLit when Control Output 2 is on. Not used Lights in the Operation Indicator Section when Indicator Name DescriptionIdentifying Temperature Controller Keys Setting the Process Air TemperatureE5CN Operating Parameters Tuned prior to dryer startup Adjustment Level Indicator Name DescriptionON, OFF Entering Operating Parameters to Select ModesProcess Air Dew Point Display Setting the High Dew Point AlarmOptional Setting the Redundant Safety Controller Redundant Safety Controller DisplayWatlow Operating Parameters Mode Parameter Setting range Default Manf. setting Dryer Operation Procedures Model Heating Cooling 15 cfm 30 cfm 60 cfm Page Controller Operation With Optional Alarm Horn & Reset Button Page Alarm Display Messages Shutting Down the Dryer Auto-Tuning the DryerPreventative Maintenance Schedule MaintenancePhotocopy this page for your maintenance records Recommendations for Cleaning and Replacing Filters Preventative MaintenanceServicing Process Air Filters VacuumingServicing the Dew Point Monitor Cleaning with Compressed AirSymptoms of Worn Desiccant Corrective MaintenanceReplacing Worn Desiccant First AIDConsult local disposal regulations for more information Replacing the Process Heater ProceduresProblem Possible cause Corrective action TroubleshootingIntroduction Problem Possible cause Corrective action Check resin manufacturer’s data Using a Thermocouple Determining Temperature Controller Errors or Sensor ErrorsUsing a Platinum Resistance Thermometer Warranty Specifications WarrantyWarranty Restrictions AppendixOptional Components Warranty LiabilitiesCustomer Responsibilities Annex B Information Technical SpecificationsAftercooler Design Specifications Drawings and Diagrams Spare Parts ListLevel 2 & 3 Spare Parts List Electrical & Mechanical Warranty Returns Safety Tag InformationDryer Safety Tags Returned Material PolicyLocated on back of Dryer Dryer Identification Serial Number TagTechnical Assistance Service DepartmentParts Department Sales Department
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