Power Transmission
any bits left over, especially nuts, bolts, washers or other seemingly unimportant parts?
10. Next you should turn your attention to the driven machinery – gears, belts, couplings. Check tensions and alignments. Starting at the motor, go through each element of the drivetrain in turn, working out what will happen when it rotates, check that it is secure, free to rotate, is not going to foul anything, etc.
11. Check, double- and treble-check that all guards and safety equipment are in place and secure.
12. Before start-up run through all the relevant safety standards and regulations. Make sure all personnel are well clear at initial start-up, just in case a part flies off!
13. Industrial environments can be harsh, but always try to find a clean, dry, cool location for motors.
14. Most motors will be operated within an enclosure for safety purposes. In industry, wire cage-type enclosures are popular because they do not trap heat around the motor, but if the general environment is damp or dirty a solid enclosure may be required, and this may need to have a cooling arrangement. Thinking about maintenance, enclosures need to be either removable or large enough to allow adequate access.
15. Motors can spark so they need to be isolated from combustible materials such as dust (settled and airborne), lint, paper, textiles and oils.
16. Motors generate heat, which must be managed. Many motor types have cooling fins, others have an integral forced draught fan (and cover, which must not be damaged). Larger motors may need additional ventilation or even water jacket cooling. Whatever the size, if a motor is in a confined space, heat can build
up to potentially dangerous levels. The motor will have a specified safe maximum working temperature, which should be ascertained and respected.
17. If the operating environment is permanently or intermittently damp, the motor will need protecting.
18. Some motors have to be installed in outdoor or damp prone locations, and it may be necessary to provide space heaters to prevent damp problems or drip proofing in the form of a roof-type cover.
19. Seagoing and shoreside motors have a very tough life, and marine specification motors are the only real solution.
20. A hot working environment (above 40˚C) will impact the motor’s insulation and thereby shorten its maintenance period – and probably its overall working life. Hence, cooling facilities can be seen as a cost-effective investment.
21. Rigid mountings are essential for minimum vibration and proper alignment between motor and load.
22. The motor mount also has to be precise, with and exact alignment to the load.
23. The electrical connections to motors are fully specified in International Standards and should be followed to the letter.
24. It is important to check that the correct specification of cables is used. High- spec cables are far more expensive than ‘standard’ cables, but do not be tempted to scrimp, as failure could be disastrous.
25. Finally, it is always worth having each motor installation checked by at least one suitably qualified engineer. l
Lucie Hodkova is with Regal UK/Rotor UK Ltd, Wellingborough, UK.
www.regal-news.com
www.engineerlive.com 27
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