Sterling AF-XXX Safety Circuit Standards, Fail Safe Operation, Safety Device Lock-Outs

Page 14

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 additive feeder; 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 additive feeders 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 additive feeders are equipped with a line cord plug. This allows the operator or maintenance personnel to unplug the additive feeder 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 additive feeder. Failure to do so may result in serious injury. No one but the person who installed the lockout may remove it.

Additive Feeders

Chapter 2: Functional Description

14 of 55

Image 14

Contents SF Series Additive Feeders Shipping Information Table of Contents Program Parameter Descriptions Safety Symbols Used in this Manual SafetyHow to Use This Manual Wear Safety Glasses and Work Gloves Responsibility General ResponsibilityOperator Responsibility RememberAdditive Feeder Safety Tags Maintenance ResponsibilityReporting a Safety Defect Functional Description Standard FeaturesMechanical Features Models Covered in This ManualOptions Electrical FeaturesController Features Accessories Safety Devices and InterlocksFail Safe Operation Safety Circuit StandardsSafety Device Lock-Outs Uncrating the Equipment InstallationSupply System Installation Rigging and Placing the Additive FeederControl Relay Connection Main Power ConnectionElectrical Connections Setup Procedures Determining the Desired Feed Rate110 100 Equipment Needed Calibration ProcedureProcedure Examples Observed Feed RatesStarting Up the Additive Feeder Initial Start-upPre-Startup Checks Shutting Down the Additive FeederOperation Timer ModuleUsed as a Cycle Override Safety Timer Start-upCounter Module Elapsed Time ModuleControl Relay Connection Injection Molding ApplicationsInjection Molding Field Control ProgrammingProgramming Step by Step Guide Resetting the Unit to Un-Programmed StateJP1 Program Enable Jumper Additive Feeders Operation Injection Mode Application Notes Extrusion Applications Extruder Tracking ControlExtruder Tracking Installation and Setup Extruder Tracking EquationValue Mode Running ModeParameter-Selection Mode Resetting the Unit to Un-Programmed State Minimum Input Pulse Rate Input Pulse Signal RequirementsExtruder Tracking Control Application Notes Maximum Input Pulse Rate Minimum and Maximum Percent SetpointsProgram Parameter Descriptions Defining Program ParametersMode 1 Default to Zero Parameter 19 Power-up Value Parameter 35 Signal Input 2 S2 Input Configuration Parameter 36 Signal Input 2 S2 Setpoint Photocopy this page for your maintenance records MaintenancePreventative Maintenance Schedule Preventative Maintenance Material Cleanout/ChangeoverRemoving Auger Assembly Corrective MaintenanceAuger Assembly Changeover Installing Auger AssemblyMotor Brush Replacement Introduction TroubleshootingProblem Possible cause Corrective action Problem Possible cause Corrective action Additive Feeders Troubleshooting Annex B Information Technical SpecificationsAppendix Drawings and Diagrams Additive Feeder Specifications and Overall DimensionsTypical Additive Feeder Controllers Spare Parts List Exploded Assembly Drawing Parts ListDetail # Part number Part/assembly description One Component Control Enclosure Parts Identification Returned Material Policy Safety Tag InformationWarranty Returns Credit ReturnsAdditive Feeder Identification Serial Number Tag Company LogoTechnical Assistance Sterling, Inc Th Street New Berlin, WIWorksheet for Charting Feed Rates