Chaining and locking
Problem: The plant has 12 fenced storage yards, and the mechanical maintenance crew requires access to all of them. In order for the crew members to carry only one key, the gates are chained and locked with 12 identically keyed padlocks. However, the electrical maintenance staff also stores material in three of the yards. How do you limit the electrical maintenance crew access only to those areas they need?
Solution: Add a second padlock to the three electrical access gates, and loop it through the first lock (as depicted in the drawing). Give the electrical maintenance staff the key to this second lock.
Contributor: Thomas W. McCort, General Foreman, Bethlehem Steel Corp., Burns Harbor Div., Chesterton, IN
Holding parts and pieces
Problem: Small springs and other parts are difficult to keep organized (and not lost) when disassembling a mechanical device or instrument. Is there a way to prevent loss pieces while facilitating easy reassembly?
Solution: Take a 2-in. wide strip of masking tape and stretch out a long piece on the workbench with the sticky side up. Place each part on the sticky tape in the order it comes off the device. If the job will be finished later or by someone else, place another strip on top (like a sandwich) to make a neat package that can be stored until required. When it is time for reassembly, all pieces are readily available in the order required.
Contributor: Ralph Dewey, Solvay Polymers Corp., Deer Park, TX
Protecting electronic equipment
Problem: System electronics operate a variety of equipment in manufacturing facilities, with switches or relays controlling power to the equipment. Solid state relays (SSRs) do not shut off completely (they allow some leakage current), which causes a voltage to occur on the load and consequently some equipment to keep running when the relay is supposed to shut it off. Disastrous results might occur. Can this problem be corrected?
Solution: Add a relatively high value resistor across the output terminals of the SSRs. This device gives the current a place to go and prevents voltage buildup. The electronic equipment can be operated normally with the resistor in parallel. The amount of current through the resistor during intentional operation is negligible.
Contributor: Jay Skolnik, Skolnik Technical Training Institute, Albuquerque, NM