Electrical machines load tests

Philosophy of quality systems Testing of electrical machines Procedure for testing Load test No-load test Tolerances in test results Certification of motors used in hazardous locations... 

An alternative approach to detecting slight over-compression with an electrical circuit is to arrange for a preset amount of over-compression. Simple jigs of this type relying on a mechanical stop will probably produce excessive over-compression and be somewhat variable in use. The actual amount of over-compression of the test piece will depend on the stiffness of the load cell and errors can be introduced by any lack of parallelism of the plates and plunger. However, if they are machined to tight tolerances, this type of jig can be very effective and relatively cheap. 

Force sensors are not used in general automotive applications. In agricultural machines a force sensor measures the load at the connection rod [1], Some force sensors are specially made for measuring forces during vehicle testing and validation. Often metal strain gauges are welded to the devices under test The data is sometimes needed for system development or to verify simulation results. The first and only mass production of torque sensors is in electrical steering systems [2]. 

Parameters of the ECG are presented in table 1. The developed BFC is tested in laboratory and in customer s plant to smooth maximal loading of system electrical ensuring of atomic electrical power station (All Union Scientific Research Institute of Atomic Machining, Moscow). 

The force measuring head, together with provision for applying the extra compression. can be a beam balance, as used in the well-known Lucas apparatu.s. a universal tensile machine, or a specially designed electronic load cell unit [4]. The point at which the small amount of extra compression has been applied can be detected by breaking an electrical circuit. An early apparatus used a load cell attached to an arbor pre,ss. The operator manually lowered the pre.ss until the break in the electrical circuit was indicated visually by the extinction of a light. The Lucas apparatus has a similar detection system the balance weights are adjusted manually until the force exerted by the beam just overcomes the force exerted by the test piece. Both of these approaches involve a somewhat... 

Specimens were strained in a push-pull mode by an Instron machine, Model TF-DM, which has cross head speeds from 0.05 to 0,5 cm/min and a load capability up to 10" kg. Details of the apparatus for the mechanical and electrical tests are reported elsewhere Only a brief description of the electrical portion is given here. The resistivity was measured by the typical four-probe dc method. A set of voltage leads were soft-soldered across the gauge length of the specimen surface. 

Under wet conditions, automatic controls for reducing no-load voltage should be used. Electrodes are to be removed from the holders when not in use. It is required that electric power to the welder be shut off when no one is in attendance. Suitable Are extinguishing equipment must be available for immediate use. The welder shall be forbidden to coil or loop welding electrode cable around his or her body. Wet machines must be thoroughly dried and tested before being used decreasing the risk of electrical shock or electrocution. 

Situation, June The first manipulator, at this stage, was installed in the prototype workshop - a big orange beast that worked quite well. This one was an off-the-shelf standard type, pneiunatic driven, and rented from a sub-supplier. The tests were performed on this rented machine however, this was not the manipulator that was to eventually end up in the factories. Firstly, because it was driven by air and pneumatics had been abolished for a long time in the factories, as it is inefficient, very noisy, and sometimes dirty. Secondly, because the manipulator that is to be used in the factories is driven by electricity, and it is to be specially made for the purpose by a local equipment supplier to The Company. There were some discussions about this. Some said that they should buy manipulators from known suppliers on an off-the-shelf basis. But it turned out that the manipulators available were too big compared to the load they could bear they were also too expensive. It was therefore decided to have them custom-made. Thereby it was possible to have a... 

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