Sterling SDA 1000-5100 specifications Safety Devices and Interlocks, Safety Circuit Standards

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2-6 Safety Devices and Interlocks

This section includes information on safety devices and procedures that are inherent to the large dehumidifying dryer. This manual is not intended to supersede or alter safety standards established by the user of this equipment. Instead, the material contained in this section is recommended to supplement these procedures in order to provide a safer working environment.

At the completion of this section, the operator and maintenance personnel will be able to do the following:

Identify and locate specific safety devices.

Understand the proper use of the safety devices provided.

Describe the function of the safety device.

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 large dehumidifying dryer; 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 the large dehumidifying dryer 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 machines.

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.

Large Dehumidifying Dryers

Functional Description

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Contents SDA Large Dehumidifying Dryers With AP0 Controls Shipping Info Unpacking and InspectionEvent of Shipping Damage If the Shipment is Not CompleteCredit Returns Warranty ReturnsReturns Table of Contents Operation Dryer Identification Serial Number Tag Technical Assistance Safety Symbols Used in this Manual SafetyHow to Use This Manual Dryer Safety Tags Description Wear Safety Glasses and Work GlovesOperator Responsibility ResponsibilityGeneral Responsibility Maintenance Responsibility Reporting a Safety Defect General Description Functional DescriptionModels Covered in This Manual Process/Regeneration Cycle Regeneration CycleSequence of Operation Controller Description Controller Screen DescriptionsElectrical Features Standard FeaturesMechanical Features Process Aftercooler OptionsClosed-Loop Regeneration Material Overdrying Protection Recommended Temperature SettingsProcess Air Dust Collector Mechanical Options Electrical OptionsSafety Devices and Interlocks Safety Circuit StandardsSafety Device Lock-Outs Fail Safe OperationPage Mechanical Installation Uncrating the EquipmentRigging and Placing Unit Making Electrical ConnectionsChecking for Proper Blower Rotation Checking Blower RotationMaking Dryer/Drying Hopper Process Air Connections Dryer/Drying Hopper Process Air ConnectionsConnecting Aftercooler/Precooler Cooling Water Optional Aftercooler Components & Flow RatesUsing the Drying Hopper Air Trap Drying Hopper Air TrapSwitches Indicator LightsProcess Air Temperature Controller ControlsLit when Control Output 1 is on. The Out1 Lit when Control Output 2 is on. Not usedIndicator Name Description Lights in the Operation Indicator Section whenSetting the Process Air Temperature E5CN Operating ParametersAdjustment Level Indicator Name Description Tuned prior to dryer startupEntering Operating Parameters to Select Modes ON, OFFOptional Setting the High Dew Point AlarmProcess Air Dew Point Display Watlow Operating Parameters Redundant Safety Controller DisplaySetting the Redundant Safety Controller Manf. setting Auto-Tuning the Dryer OperationInitial Start-up Pre-Startup ChecksDryer Operation Procedures Page Material Miser OFF Press + to Enable Alarm Display Messages Auto-Tuning the Dryer Shutting Down the DryerPhotocopy this page for your maintenance records MaintenanceMaintenance Schedule Preventative Maintenance Cleaning or Replacing the Process Air FiltersCleaning or Replacing the Regeneration Filter Calibrating the Dirty Filter AlarmChecking the Dewpoint Control System Replacing the Desiccant Corrective MaintenanceSymptoms of Worn Out Desiccant Desiccant Tower Assembly Replacing the Process Heater Electric DryersProcess Heater Box Assembly Replacing the Regeneration Heater Electric DryersRegeneration Heater Box Assembly Introduction TroubleshootingBasic Troubleshooting Large Dehumidifying Dryers Troubleshooting Alarm Alarm Description Alarm Effect Code AlarmsAlarm Descriptions Using a Platinum Resistance Thermometer Determining Temperature Controller Errors or Sensor ErrorsUsing a Thermocouple Warranty AppendixAnnex B Information Technical SpecificationsAftercooler Design Specifications Drawings and Diagrams Optional dryer dust collector Spare Parts List Level 3 Mechanical Components Dryer Identification Serial Number Tag Located on back of DryerParts and Service Department Service Department Technical AssistanceParts Department Sales Department