User Guide

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.
General Information 17