Industrial Automation Safety Rules For Different Zones in Industrial Automation Presented by Manoranjan Sahoo EI200117259 Under the guidance of Mr. Bhawani Shankar Pattnaik

greater than the limit risk. Safety is a situation, whereby the risk is not greater than the limit risk. Risk is a combination of the probability and the degree of the possible injury or damage to health in a hazardous situation. Safety is relative. There is no such thing as 100% safety. INTRODUCTION

The Margin Between Danger and Safety Danger: The risk is greater than the limit risk. Safety: The risk is not greater than the limit risk. Limit risk: The maximum acceptable level of risk. Residual risk: Risk remaining after safety measures has taken.

Prevention of accidents Why Safety? Prevention of accidents Protection in the workplace. Cost effective.

DIFFERENT SAFETY STANDARDS ANSI:- American National Standards Institute. IEC:- International Electrotechnical Commission. DIN:- Deutsches Institute of Normung OSHA:- Occupational Safety and Health Administration EU:- European economic Union (EN-standards)

Safety Integrity Level Probability of failure on demand SAFETY ZONES Safety Integrity Level Probability of failure on demand 1 >=10^-5 to <10^-4 2 >=10^-4 to <10^-3 3 >=10^-3 to <10^-2 4 >=10^-2 to <10^-1 Relation between SIL and PFD Relation between SIL and SC

SAFETY RULES Flow chart for the iterative process to achieve safety

Risk analysis: Determination of the Limits of Machinery All phases of machinery life The limits of machinery including the intended use The full range of foreseeable uses of the machinery The anticipated level of training, experience, and ability of the user Exposure of other persons to the hazards of the machinery Hazard Identification Risk Estimation

Risk Evaluation and Reduction Safe machinery design Protection measures for the risks that can’t be eliminated Inform users of the residual risks Information, instruction, training and supervision Use of Personal Protection Equipment

Area Guarding Switch off power when a person enters the hazard area Prevent switching on power when a person is in the hazard area. Trip and Area guarding Trip and presence sensing device

Choice of Protective Measures 1. Preventing access during dangerous motion Fixed Guards Movable Guards Two-Hand Controls Preventing dangerous motion during access. Photoelectric Light Curtains Pressure Sensitive Safety Mats Pressure Sensitive Edges

Fixed guard Movable guard Two Hand control

Photoelectric Light Curtain Pressure Sensitive Safety Mat Pressure Sensitive Edge

Emergency Stops Telescopic Trip Switches Cable Pull Switches

Safety light curtains fall into three product families 1. Point of Operation Control 2. Area Access Control

Safety Light Curtains Function Advantages Greater productivity Ergonomically sound Frequent and easy access 3. Perimeter Access Control

Blanking- Fixed and Floating Floating blanking Fixed Blanking

Muting The muting conditions defined in IEC 61508: a. Muting is only permitted to be activated during the time span of the working cycle b. Muting must be performed automatically. c. Muting must not depend on a single electrical signal. d. Muting must not depend completely on software signals. e. The muting signals, if they occur as part of an invalid combination, must not permit any muting state. f. The muting state is removed immediately after the pallet has passed through

Muting

R = I + d How to choose the device 3 characteristics of a device: Resolution The height of the protected area The safety distance R = Resolution I = Inter-axis distance d = Diameter Resolution visualization Resolution for body Protection

The height of the protected area HCA = HSA+2I Where HCA = Height of the controlled area HSA = Height of the sensitive area I = Inter Axis distance

The safety distance OSHA Formula: Ds = 63 X TS where Ds= Safety Distance 63 = Recommended hand speed in in/sec TS = Total stop time in Sec ANSI Formula: Ds = K x (Ts + Tc + Tr + Tbm) + Dpf Ds = The minimum safe distance K = 63 (hand speed in in/sec) Ts = Stopping time of machine, in seconds Tc = Control circuit response time in seconds Tr = Light curtain response time Tbm = Response time of a brake monitor Dpf = Depth penetration factor EN 1050 Formula: S = (K x T) + C K = 1600mm/sec assumed operator speed T = The overall stopping time of the system C = Depth of penetration S = Safety distance

High efficiency is required High accuracy is required CONCLUSION High efficiency is required High accuracy is required Complexity increases Terrorism increases Safety is required

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