Maintenance Technology April 2016 - (Page 40)

PROCESS EQUIPMENT International Standards that Apply to Emergency Stops vs. Stop Switches Choose The Right Emergency Stop WITH TODAY'S NUMBER of customizable available options, selecting the right emergency stop (e-stop) for process equipment can be a daunting task, but it's critical for overall safety. According to human-machine-interface (HMI) experts at EAO Corp., Shelton, CT, fitting equipment with a highly functional e-stop in line with the basic application design concept, versus a lesser-certified safety switch, is key. MT Determine if your application requires Category 0 or Category 1 shutdown. This is crucial in the placement, size, electrical specifications, mechanical characteristics, color, and number of required e-stops. Research international and North American standards, performance ratings, and codes that govern your application (see table). Each industry has unique regulatory standards. These restrictions may govern factors such as size, color, and contact terminals. Select the product. Choose your e-stop based on design factors to meet industry demands and international compliance. Proper selection involves understanding market and application requirements, environmental conditions, and electrical demands. Emergency Stop Stop Switch Color of actuator Actuators of emergency switching off devices shall be colored RED. ■ EN IEC 60947-5-5 § 4.2.1 ■ EN 60204-1 § 10.8.3 ■ DIN EN ISO 13850 § 4.4.5 Not defined Actuator/ Background When a background exists behind the actuator, and as far as it is practicable, it shall be colored yellow. ■ EN IEC 60947-5-5, 4.2.1 ■ EN 60204-1, 10.8.3 ■ DIN EN ISO 13850 § 4.4.5 Not defined Inscription of actuator The direction of unlatching shall be clearly identified when resetting is achieved by rotation of the button. ■ EN IEC 60947-5-5 § 4.2.1 Not defined General Electrical requirements Utilization categories The utilization categories shall be AC-15 and/ or DC-13 and/or DC-14 in accordance with EN 60947-5-1. ■ EN IEC 60947-5-5 § 5.1 Not defined Direct opening action All normally closed contact elements of an emergency stop device shall hav a direct opening action (positive opening action). ■ EN IEC 60947-5-5 § 5.2 Not necessary Latching It shall not be possible for the emergency stop device to latch-in without generating the emergency stop signal. ■ EN IEC 60947-5-5 § 6.2.1 Not defined Resetting Resetting of the emergency stop shall only be possible as the result of a manual action at the location where the emergency stop was initiated. ■ EN ISO 13850, 4.4.4 Not defined Resetting The resetting of the latching means shall be by rotation of the button in the designated direction, or by a pulling motion. ■ EN IEC 60947-5-5 § 6.3.1 Not defined, but usually realized by turning a key, by rotation of the button in the designated direction, or by a pulling motion. Testing Robustness A button actuator shall withstand a torque as speciof a button fied below, in both directions of latched actuator and unlatched positions, where the resetting action requires activator rotation of the push-button. ■ EN IEC 60947-5-5 § 7.3.2 Accessorize. Vendors often provide a variety of unique features to enhance your e-stop and complete virtually any application. It's important to research these additions as some accessories may be mandated by industry standards. Consult an expert. Many suppliers offer consultative services to assist customers throughout the process of selecting and integrating their HMI needs, from individual e-stops to completely designed and produced 'mixed technology' solutions. For more information on e-stops and other HMI components and systems, visit 40 | MAINTENANCE TECHNOLOGY Not defined Ø Durability test Force Torque 16 mm 80 N 1.6 Nm 22 mm 110 N 2.2 Nm 30 mm 150 N 3.0 Nm The test shall consist of 6,050 cycles in which latching and resetting of the actuator occurs during each cycle.The movement and actuating forces shall be consistent throughout the test. Monitoring of these parameters shall be carried out to ensure consistency. ■ EN IEC 60947-5-5 § 7.3.3 Not defined Norms Mandatory standards ■ EN IEC60947-5-5 (International Standard) ■ EN ISO 13850 (Safety of Machinery) ■ EN 60204-1 (Safety of Machinery) Not defined APRIL 2016

Table of Contents for the Digital Edition of Maintenance Technology April 2016

My Take
On The Floor
Culture Changed At This Indiana Refinery
She Ignores The Glass Ceiling
Loadability Studies Aid PRC-025-1 Compliance
Look System-Wide For Cost Savings
Reliable Pumping Supplement
Fund Lubrication Program With Energy Savings
Emergency-Stop Choices
Cyber Security
Backup Generators
Infrared Safety Tips
Internet Of Things
ISO 55000
Motor-Testing Tools Expand Services
Ad Index
Final Thought

Maintenance Technology April 2016