Robot Safety

Safety During Installation and Commissioning

Layout

The robot integrated to a robot system shall be designed to allow safe access to all spaces during installation, operation, maintenance, and repair.

If robot movement can be initiated from an external control panel, an Emergency Stop (E-Stop) must also be available.

If the manipulator is delivered with mechanical stops, these can be used for reducing the working space.

A perimeter safeguarding, for example a fence, shall be dimensioned to withstand the following:

• The force of the manipulator
• The force of the load handled by the robot if dropped or released at maximum speed
• The maximum possible impact caused by a breaking or malfunctioning rotating tool or other device fitted to the robot
• The maximum TCP speed and the maximum velocity of the robot axes detailed in the section Robot motion in the product specification for the respective manipulator
• Consider exposure to hazards, such as slipping, tripping, and falling
• Hazards due to the working position and posture for a person working with or near the robot shall be performed and applied
• Hazards due to noise emission from the robot needs to be considered

Consider hazards from other equipment in the robot system, for example, that guards remain active until identified hazards are reduced to an acceptable level.

Securing the Robot to the Foundation

The robot must be properly fixed to its foundation/support as described in the respective product manual.

When the robot is installed at a height, hanging, or other than mounted directly on the floor, there will be additional hazards.

Electrical Safety

Incoming mains must be installed to fulfill national regulations.

The power supply wiring to the robot must be sufficiently fused and if necessary, it must be possible to disconnect it manually from the mains power.

The power to the robot must be turned Off with the main switch and the mains power disconnected when performing work inside the controller cabinet. Lock and tag shall be considered.

Harnesses between controller and manipulator shall be fixed and protected to avoid tripping and wear.

Wherever possible, power On/Off or rebooting the robot controller shall be performed with all persons outside the safeguarded space.

Safety Devices

The integrator is responsible for that the safety devices necessary to protect people working with the robot system are designed and installed correctly.

When integrating the robot with external devices to a robot system:

• The integrator of the robot system must ensure that Emergency Stop (E-Stop) functions are interlocked in accordance with applicable standards.
• The integrator of the robot system must ensure that safety functions are interlocked in accordance with applicable standards.

Other Hazards

A robot may perform unexpected limited movement.

The risk assessment should also consider other hazards arising from the application, such as, but not limited to:

• Water
• Compressed air
• Hydraulics

End-effector hazards require particular attention for applications which involve close human collaboration with the robot.

Pneumatic or Hydraulic Related hazards

Loss of pressure in the robot system may cause parts or objects to drop.

Dump valves should be used in case of emergency.

Shot bolts should be used to prevent tools, etc., from falling due to gravity.

All pipes, hoses, and connections have to be inspected regularly for leaks and damage. Damage must be repaired immediately.

Verify the Safety Functions

Before the robot system is put into operation, verify that the safety functions are working as intended and that any remaining hazards identified in the risk assessment are mitigated to an acceptable level.

Safety During Operation

Automatic Operation

Verify the application in the operating mode manual reduced speed before changing mode to automatic and initiating automatic operation.

Unexpected Movement of Robot Arm

A robot may perform unexpected limited movement.

FlexPendant

The enabling switch on the FlexPendant is a manually operated, constant pressure button 3-position switch when pressed and held in the mid position, allows potentially hazardous functions but does not initiate them. To initiate, the enabling switch must be held in at mid-position while simultaneously pressing a function button on the FlexPendant. If the enabling switch is pressed fully in or released to the fully out position, the potentially hazardous functions are stopped safely. The enabling switch is sometimes referred to as the "Live Man Switch".

The enabling device located on the side of the FlexPendant which, when pressed half-way in, switches the system to MOTORS ON. When the enabling device is released fully or pressed in fully, the manipulator switches to the MOTORS OFF state.

To ensure the safe use of the FlexPendant, the following must be implemented:

• The enabling device must never be rendered inoperable in any way.
• During programming and troubleshooting, the enabling device must be released as soon as there is no need for the manipulator to move.
• Anyone entering the manipulator working space must always bring the FlexPendant with him/her. This is to prevent anyone else from taking control of the manipulator without his/her knowledge.

Robot Safety During Automatic Operation

All personnel who operate the robot during production to observe the following rules:

• Make sure all safety provisions are present and active.
• Know the entire work cell area. The work cell includes the robot and its work envelope, plus the area occupied by all external devices and other equipment with which the robot interacts.
• Understand the complete task the robot is programmed to perform before initiating automatic operation.
• Make sure all personnel are outside the work envelope before operating the robot.
• Never enter or allow others to enter the work envelope during automatic operation of the robot.
• Know the location and status of all switches, sensors, and control signals that could cause the robot to move.
• Know where the Emergency Stop (E-Stop) buttons are located on both the robot control and external control devices. Be prepared to press these buttons in an emergency.
• Never assume that a program is complete if the robot is not moving. The robot could be waiting for an input signal that will permit it to continue activity.
• If the robot is running in a pattern, do not assume it will continue to run in the same pattern.
• Never try to stop the robot, or break its motion, with your body. The only way to stop robot motion immediately is to press an E-Stop button located on the controller panel, teach pendant, or Emergency Stop stations around the work cell.

Robot Safety During Inspection

When inspecting the robot, be sure to:

• Turn off power at the controller.
• Lockout / Tagout (LOTO) the power source at the controller according to the policies of your plant.
• Turn off the compressed air source and relieve the air pressure.
• If robot motion is not needed for inspecting the electrical circuits, press the E-Stop button on the operator panel.
• Never wear watches, rings, neckties, scarves, or loose clothing that could get caught in moving machinery.
• If power is needed to check the robot motion or electrical circuits, be prepared to press the E-Stop button in an emergency.
• Be aware that when you remove a servomotor or brake, the associated robot arm will fall if it is not supported or resting on a hard stop. Support the arm on a solid support before you release the brake.

Robot Safety During Maintenance

When performing maintenance on your robot system, observe the following rules:

• Never enter the work envelope while the robot or a program is in operation.
• Before entering the work envelope, visually inspect the work cell to make sure no potentially hazardous conditions exist.
• Never wear watches, rings, neckties, scarves, or loose clothing that could get caught in moving machinery.
• Consider all or any overlapping work envelopes of adjoining robots when standing in a work envelope.
• Test the teach pendant for proper operation before entering the work envelope.
• If it is necessary for you to enter the robot work envelope while power is turned on, you must be sure that you are in control of the robot. Be sure to take the teach pendant with you, press the DEADMAN switch, and turn the teach pendant on. Be prepared to release the DEADMAN switch to turn off servo power to the robot immediately.
• Whenever possible, perform maintenance with the power turned off. Before you open the controller, front panel or enter the work envelope, turn off and lock out the 3-phase power source at the controller.
• Be aware that an applicator bell cup can continue to spin at a very high speed even if the robot is idle. Use protective gloves or disable bearing air and turbine air before servicing these items.

Hold-to-Run Function

The hold-to-run function allows movement when the button associated with the function is pressed and held and immediately stops any movement when the button is released. The hold-to-run function can only be used in manual mode.

Work Inside the Manipulator Working Range

If work must be carried out within the manipulator's work area, the following points must be observed:

• The operating mode selector switch on the controller must be set to the "Manual Mode" position to render the enabling device operational and to block operation from a computer link or Main Operator Panel (MOP).
• The manipulator's speed is limited to max 250mm/s when the operating mode selector is in the position Manual Mode with Reduced Speed. This should be the normal position when entering the workspace.
• Pay attention to the rotating axes of the manipulator. Keep away from axes to not get entangled with hair or clothing. Also, be aware of any danger that may be caused by rotating tools or other devices mounted on the manipulator or inside the cell.
• To prevent anyone else from taking control of the manipulator, always put a safety padlock on the cell door and bring the FlexPendant device with you when entering into the working space.

Safety During Maintenance and Repair

Corrective maintenance must only be carried out by personnel trained on the robot.

Maintenance or repair must be done with all electrical, pneumatic, and hydraulic power switched off Lockout / Tagout (LOTO), that is, no remaining hazards.

Hazards due to stored mechanical energy in the manipulator for the purpose of counterbalancing axes must be considered before maintenance or repair.

Never use the robot as a ladder, which means do not climb on the controller, manipulator, including motors, or other parts. There are hazards of slipping and falling. The robot might be damaged.

Make sure that there are no loose screws, turnings, or other unexpected parts remaining after work on the robot has been performed.

When the work is completed, verify that the safety functions are working as intended.

Hot Surfaces

Surfaces can be hot after running the robot, and touching these may result in burns. Allow the surfaces to cool down before maintenance or repair.

Allergic Reaction

Gear Lubricants (Oil or Grease)

When handling oil, grease, or other chemical substances the safety information of the respective manufacturer must be observed.

Warning	Description	Elimination/Action
Hot Oil or Grease	Changing and draining gearbox oil or grease may require handling hot lubricant heated up to 90° C.	Make sure that protective gear like goggles and gloves are always worn during this activity.
Allergic Reaction	When working with lubricants there is a risk of an allergic reaction.	Make sure that protective gear like goggles and gloves are always worn.
Possible Pressure Build-Up in Gearbox	When opening the oil or grease plug, there may be pressure present in the gearbox, causing lubricant to spray from the opening.	Open the plug carefully and keep away from the opening. Do not overfill the gearbox when filling.
Do Not Overfill	Overfilling of gearbox lubricant can lead to internal over-pressure inside the gearbox which in turn may: Damage seals and gaskets. Completely pressed out seals and gaskets. Prevent the robot from moving freely.	Make sure not to overfill the gearbox when filling it with oil or grease. After filling, verify that the level is correct.
Heat Up the Oil	Warm oil drains quicker than cold oil.	Run the robot before changing the gearbox oil, if possible.
Specified Amount Depends on Drained Volume	The specified amount of oil or grease is based on the total volume of the gearbox. When changing the lubricant, the amount refilled may differ from the specified amount, depending on how much has previously been drained from the gearbox.	After filling, verify that the level is correct.

Hazards Related to Batteries

Under rated conditions, the electrode materials and liquid electrolyte in the batteries are sealed and not exposed to the outside.

There is a hazard in case of abuse (mechanical, thermal, and electrical) which leads to the activation of safety valves and/or the rupture of the battery container. As a result under certain circumstances, electrolyte leakage and electrode materials reaction with moisture/water or battery vent/explosion/fire may follow.

Do not short circuit, recharge, puncture, incinerate, crush, immerse, force discharge, or expose to temperatures above the declared operating temperature range of the product. Doing so increases the risks of fire or explosion.

Safety During Troubleshooting

When troubleshooting requires work with power switched on, special considerations must be taken:

• Safety circuits might be muted or disconnected.
• Electrical parts must be considered as live.
• The manipulator can move unexpectedly at any time.

A risk assessment must be done to address both robot and robot system specific hazards.

A robot may perform unexpected limited movement.

Safety During Decommissioning

If the robot is decommissioned for storage, take extra precaution to reset safety devices to delivery status.

Unexpected Movement of Robot Arm

A robot may perform unexpected limited movement.