Sterling SDA Series 25-100 Safety Circuit Standards, Fail Safe Operation, Safety Device Lock-Outs

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Safety Circuit Standards

Safety Circuit Standards

Safety circuits used in industrial systems protect the operator and maintenance personnel from dangerous energy. They also provide a means of locking out or isolating the energy for servicing equipment.

Various agencies have contributed to the establishment of safety standards that apply to the design and manufacture of automated equipment. The Occupational Safety and Health Administration (OSHA) and the Joint Industrial council (JIC) are just a few of the organizations that have joined with the plastics industry to develop safety standards.

Every effort has been made to incorporate these standards into the design of the drying system; however, it is the responsibility of the personnel operating and maintaining the equipment to familiarize themselves with the safety procedures and the proper use of any safety devices.

Fail Safe Operation

If a safety device or circuit should fail, the design must be such that the failure causes a “Safe” condition. As an example, a safety switch must be a normally open switch. The switch must be held closed with the device it is to protect. If the switch fails, it will go to the open condition, tripping out the safety circuit.

At no time should the safety device fail and allow the operation to continue. For example, if a safety switch is guarding a motor, and the safety switch fails, the motor should not be able to run.

Safety Device Lock-Outs

Some safety devices disconnect electrical energy from a circuit. The safety devices that are used on these dryers are primarily concerned with electrical power disconnection and the disabling of moving parts that may need to be accessed during the normal operation of the machine.

Some of the safety devices utilize a manual activator. This is the method of initiating the safety lock out. This may be in the form of a plug, lever or a handle. Within this lockable handle, there may be a location for a padlock. Personnel servicing the equipment should place a padlock in the lockout handle.

In addition to the safety devices listed above, these dryers are equipped with a line cord plug. This allows the operator or maintenance personnel to unplug the dryer from its power source and tag it out. The plug can then be tagged with any number of approved electrical lockout tags available at most electrical supply stores.

WARNING! Always disconnect and lockout all electrical power and pneumatic (i.e. compressed air) sources prior to servicing or cleaning the dryer. Failure to do so may result in serious injury. No one but the person who installed the lockout may remove it.

15, 30, & 60 cfm Compact Dryers

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Contents SDA Series 15-60cfm Compact Dehumidifying Dryers Unpacking and Inspection Shipping InformationIn the Event of Shipping Damage If the Shipment is Not CompleteCHAPTER 3 INSTALLATION Table of ContentsCHAPTER 1 SAFETY CHAPTER 2: FUNCTIONAL DESCRIPTIONCHAPTER 6 TROUBLESHOOTING CHAPTER 5 MAINTENANCECHAPTER 7 APPENDIX 15, 30, & 60 cfm Compact Dryers1-1How to Use This Manual Chapter 1 SafetySafety Symbols Used in this Manual 1-3Warnings and Precautions 1-2Safety Tag InformationRead Operation and Installation Manual Dryer Safety TagsGeneral Responsibility 1-4ResponsibilityOperator Responsibility REMEMBER Reporting a Safety Defect Maintenance Responsibility2-1Models Covered in This Manual Chapter 2 Functional Description2-2General Description What is desiccant?Figure 1 Typical Dryer Air Flow Schematic 2-3Standard FeaturesMechanical Features Electrical Features2-4Options 2-5Safety Devices and InterlocksController Features Safety Device Lock-Outs Safety Circuit StandardsFail Safe Operation 3-1Uncrating the Equipment Chapter 3 Installation3-2Rigging and Placing the Dryer 15, 30, & 60 cfm Compact Dryers POWER ONDEW POINT 3-3Electrical Connections Three-PhaseModels 3-4Setup ProceduresChecking for Proper Blower Rotation Floor Mount ModelsInstalling Water Lines 3-5Initial Start-upDrying Hopper Air Trap Considerations Optional AftercoolerShutting Down the Dryer Auto-Tuningthe Dryer4-1Controller Description and Operation Chapter 4 OperationSwitches Indicator LightsPV SV Process Air Temperature ControllerLit when Control Output 1 is on. The Out1 IndicatorLit when Control Output 2 is on. Not used in IndicatorIndicator Setting the Process Air TemperatureAdjustment Level IndicatorName IndicatorDescription Entering Operating Parameters to Select ModesProcess Air Dew Point Display Setting the High Dew Point AlarmOptional Controller Operation 4-2Dryer Operation ProceduresAlarm Display Messages HEAT COOL 50 SYSTEM NORMAL HIGH TEMP VALVE MTRValve Motor Time-Out Blower Overload No Alarms PROC BLWR5-1Preventative Maintenance Schedule Chapter 5 MaintenanceEvery Day Every weekFigure 9 Air Filter Location and Disassembly 5-2Preventative MaintenanceServicing Process Air Filters VacuumingCleaning with Compressed Air 5-3Corrective MaintenanceSymptoms of Worn Desiccant Servicing the Dew Point MonitorReplacing Worn Desiccant + FIRST AID +Figure 11 Required Desiccant Amounts 13X Type Figure 10 Desiccant Bed Location and DisassemblyReplacing the Process/Regeneration Heater ProceduresWARNING! Hazardous electrical current present Figure 13 Cooling Coil Location and Disassembly Replacing/Cleaning the Cooling CoilReplacement Procedures If used as an after-Cooler 3 to 4 GPM @ 85F9.Turn the water to the cooling coil back on 8.Inset the four 10-32bolts back in place15, 30, & 60 cfm Compact Dryers 6-1Introduction Chapter 6 TroubleshootingHIGH TEMP Alarm Message PROC BLWRHIGH TEMP CauseUsing a Thermocouple VALVE MTRAlarm Message CauseChapter 7 Appendix 7-1WarrantyWarranty Specifications Warranty RestrictionsCustomer Responsibilities 7-2Technical SpecificationsAnnex B Information Aftercooler Design Specifications 7-3Drawings and DiagramsRegeneration MoistureMake Up Air Exhaust High Pressure Peripheral BlowerAfter-Cooler Regeneration MoistureMake Up Air Figure 16 Low Heat Model 120F to 250F Air FlowExhaust High Pressure Peripheral BlowerDRYER SPARE PARTS LIST 15, 30, 60 cfm Models 7-4Spare Parts List15, 30, & 60 cfm Compact Dryers Mechanical ComponentsHI-COREDESICCANT DRYER 15/30/60 CFM UNITS 15, 30, & 60 cfm Compact Dryers30 CFM 15, 30, & 60 cfm Compact DryersDescription 60 CFM 15, 30, & 60 cfm Compact DryersDescription A0571672 15, 30, & 60 cfm Compact Dryers120V CONTROL COMMON PARTS DescriptionCredit Returns 7-5Returned Material Policy7-7Technical Assistance 7-6Dryer Identification Serial Number TagWarranty Returns Service Department15, 30, & 60 cfm Compact Dryers Contract Department