Sterlco SSC Conveying Systems - Manual (Page 15)

Page 14 of 38
2-7 Safety Devices
This section includes information on safety devices and
procedures that are inherent to the SSC1-5Q Controller. 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.
2-7-1 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 SPD/SPC 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.
2-7-2 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