Machines ratings, 575-6 testing

Guide for testing insulation resistance of rotating machines, rated for 1 MW and above Electrical Relays. 7816/1991 ... 

The cleavage test utilizes a specimen where the load is intentionally placed on one edge of the bonded area. The test method is described in ASTM D 1062. The specimen is usually loaded at a rate of 0.05 in/min until failure occurs. The failing load is reported as breaking load per unit area in pounds per square inch. A standard test specimen is illustrated in Fig. 20.9. Because cleavage test specimens involve considerable machining, peel tests are usually preferred where possible. 

Tests on crushed rock with type-2 machine. Rate of feeding test-JL 380 tons in 10 hr. Test-R, rate of feeding 250 tons in 10 hr. 

The first main feature of the System 4 RMS is its ability to characterize a wider range of the above systems than any other current rheometer. Several drives and stress transducers are required the wide range of modes, rates and materials to be handled would mean that no single drive/transducer combination would be sufficiently flexible and accurate. Instead, the System 4 RMS uses a turret with four different drive or transducer units one unit is used for steady shear tests, one for oscillatory shear, one for tension-compression and bending and one unit is used for low-viscosity-high-shear-rate tests on fluids. The second main feature of the new machine is its completely automatic microprocessor control coupled with data acquisition and reduction. Without doubt, this new rheometer will result in rheo-metrical tests being carried out more reliably, accurately and quickly than previously. 

D-samples (ready for series production phase), should be produced in a qualified series production process including all machines and test facilities as defined in the control plan and during PPAP (Production Part Approval Process). During Run-at-Rate a defined number of samples should be produced so that the quality characteristics and the performance of the production process can be assured also during series development conditions. The produced sample is then seen as the basis for the customer (e.g. the vehicle manufacturer) for the release for serial production. 

The principal type of shear test specimen used in the industry, the lap shear specimen, is 2.54 cm wide and has a 3.23-cm overlap bonded by the adhesive. Adherends are chosen according to the industry aluminum for aerospace, steel for automotive, and wood for constmction appHcations. Adhesive joints made in this fashion are tested to failure in a tensile testing machine. The temperature of test, as weU as the rate of extension, are specified. Results are presented in units of pressure, where the area of the adhesive bond is considered to be the area over which the force is appHed. Although the 3.23-cm ... 

Peel tests are accompHshed using many different geometries. In the simplest peel test, the T-peel test, the adherends are identical in size, shape, and thickness. Adherends are attached at thek ends to a tensile testing machine and then separated in a "T" fashion. The temperature of the test, as well as the rate of adherend separation, is specified. The force requked to open the adhesive bond is measured and the results are reported in terms of newtons per meter (pounds per inch, ppi). There are many other peel test configurations, each dependent upon the adhesive appHcation. Such tests are well described in the ASTM hterature. 

Vacuum filters are usually simulated with a Buchner funnel test or filter leaf test (54). The measured parameters are cake weight, cake moisture, and filtration rate. Retention aids are usually evaluated using the Britt jar test, also called the Dynamic Drainage Jar, which simulates the shear conditions found on the paper machine and predicts performance (55). 

The summation term is the mass broken into size interval / from all size intervals between j and /, and S is the mass broken from size internal i. Thus for a given feed material the product size distribution after a given time in a mill may be deterrnined. In practice however, both S and b are dependent on particle size, material, and the machine utilized. It is also expected that specific rate of breakage should decrease with decreasing particle size, and this is found to be tme. Such an approach has been shown to give reasonably accurate predictions when all conditions are known however, in practical appHcations severe limitations are met owing to inadequate data and scale-up uncertainties. Hence it is stiH the usual practice to carry out tests on equipment to be sure of predictions. 

A useful approximation of B for a conical hopper is B = 22f/a, where a is the bulk density of the stored product. The apparatus for determining the properties of solids has been developed and is offered for sale by the consulting firm of Jenike and Johansen, Winchester, Massachusetts, which also performs these tests on a contract basis. The flow-factor FF tester, a constant-rate-of-strain, direct-shear-type machine, gives the locus of points for the FF cui ve as well as ( ), the... 

NEMA/MG-1/1993 NEMA/MG-2/1989 Motor and generators ratings, construction, testing and performance Safety Standards (enclosures) for construction and guide for selection, installation and use of rotating machines ... 

Impulse voltage withstand test of the insulation system for rated voltages 2.4 kV and above for machines wound with formed coils 11/261... 

This test is intended to determine the temperature rise in different parts of the motor windings while running at rated conditions and the permissible temperature rise limits are specified in Table 11.1. While preparing for the temperature rise test the motor should be shielded from currents of air coming from adjacent pulleys, belts and other components to avoid inaccurate results. Sufficient floor space should be left between the machines... 

For continuously rated machines, readings should be taken at intervals of one hour or less. For non-continuously rated machines, readings should be taken at intervals consistent with the time rating of the machine. The temperature rise test should continue until there is a variation of 1°C or less between the two consecutive measurements of temperature. 

The standard melt flow index machine is often used for characterising the flow properties of polypropylene and to provide a rough measure of molecular weight. Under the conditions normally employed for polyethylene (2.16 kg load at 190°C) the flow rate is too low for accurate measurement and in practice higher loads, e.g. 10 kg, and/or higher temperatures are used. It has been found that a considerable pressure drop exists in the barrel so that the flow towards the end of a test run is higher than at the beginning. 

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