Enclosures tests

SAE J168-1970, Protective Enclosures-Test Procedures and Performance Requirements, IBR approved for 1926.1002(a). 

Shut down ignition sources. Ventilate area with explosion/spark proof equipment. If possible, remove leak to exhausted enclosure. Test area for oxygen deficiency before re-entiy. 

Other tests such as fire exposure and battery enclosure tests should also be performed. 

Smoke tests. In order to attain a qualitative flow assessment inside the CCGT enclosure, tests were carried out using a smoke generator and recorded on video. The smoke used had a similar density to air and had the effect of making the airflow patterns visible inside the enclosure. The solid flooring resulted in a reduction in effective air movement and replacement with open flooring grid was recommended. 

In the standard method, the metal enclosure (called the air chamber) used to hold the hydrocarbon vapors is immersed in water before the test, then drained but not dried. This mode of operation, often designated as the wet bomb" is stipulated for all materials that are exclusively petroleum. But if the fuels contain alcohols or other organic products soluble in water, the apparatus must be dried in order that the vapors are not absorbed by the water on the walls. This technique is called the dry bomb" it results in RVP values higher by about 100 mbar for some oxygenated motor fuels. When examining the numerical results, it is thus important to know the technique employed. In any case, the dry bomb method is preferred. 

J. B. Olson, "Design, Development and Testing of a Lightweight Bird-Proof Cockpit Enclosure for the E-111," presented at The Conference on Aerospace Transparent Materials and Enclosures, Long Beach, Calif., Apr. 24—28,1977. 

Experiments and even production operations can be conducted at any frequency providing the radiated and conducted signals meet the apphcable tfi limits for ISM equipment. Tests to certify this stipulation must be carried out before inception of operations. This implies weU-shielded enclosures at high power levels which is expensive but justified in certain apphcations. 

The EPA regulation prohibits more than 2 grams per test to escape into the atmosphere (114). The test consists of a diurnal cycle of 1 hour where the temperature of the fuel is raised from 15.6 to 28.9°C during a 17 mile mn on a chassis dynamometer. An immediate hot soak in a shed enclosure follows the dynamometer mn. 

Environmental Enclosures Enclosures for valve accessories are sometimes required to provide protection from specific environmental conditions. The National Electrical Manufacturers Association (NEMA) provides descriptions and test methods for equipment used in specific environmental conditions in NEMA 250. Protection against rain, windblown dust, hose-directed water, and external ice formation are examples of environmental conditions that are covered by NEMA standards. 

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 ... 

To fulfil the above requirements the material inputs for the motor, such as stampings, steel, enamelled copper wire, insulations and varnishes, bearings, enclosure materials and hardware must be subjected to a series of acceptance tests according to norms and standard specifications. For example, enamelled copper wire used... 

We have defined the various types of enclosures adopted by various manufacturers to suit different locations and environmental conditions in Tables 1.10 and 1.11. Here we briefly discuss methods for testing these enclosures to check their compliance with defined requirements. 

The test is carried out with a sphere of 50 mm diameter. The sphere should not touch live or moving parts inside the enclosure. 

The te.st is carried out by using an apparatus shown in Figure 11.8, consisting of a closed test chamber in which talcum powder can pass through a sieve having square openings of 75 fim, and is held in suspension by an air current. The amount of talcum powder is supplied at 2 kg per cubic metre size of the test chamber. The enclosure under lest is placed inside the chamber and is connected to a vacuum pump which maintains, inside the enclosure, a differential pressure equivalent to not more than a 200 mm eolumn of water. 

If, with a vacuum equivalent to a 200 mm column of water, it is not possible to draw air 80 times the volume of the enclosure under test, the test must be continued until the value is attained. In no case must the lest be carried out for more than 8 hours. 

The permissible amount of talcum powder penetrating the enclosure should not affect operation of the equipment. The test is similar as for number 5 but now no deposit of dust should be observed at the end of the test. 

After the test the amount of w-ater w hich might have entered the interior of the enclosure should not interfere with satisfactory operation of the equipment. No w-aier should accumulate near the cable gland plate or enter the cables. 

The test equipment is the same as described for degree of protection I. But the enclosure under lest is tilted up to an angle of 15° in respect of its normal operating position successively, in iw o planes at right angles (to cover all four sides). The total duration of the test will be 10 minutes (2.5 minutes each side). The lesl results should be the same as for degree of protection I. 

The enclosure under test is mounted in its normal position on a turntable, the axis of which will be vertical and height variable, located near the centre of the semi-circle formed by the oscillating tube. The table is rotated to spray all parts of the enclosure equally. The enclosure should be kept under a spray of water for 10 minutes. The lesl results should be the same as for degree of protection 1. 

The test is carried out by washing down the test enclosures in every direction by means of a standard hose nozzle of 6.3 mm inside diameter, as illustrated in Figure 11.11, held at 3 m from the enclosure with a water pressure equal lo a head of nearly 3 m of water (— 30 kN/iiF), enough to give a delivery rate of 12.5 litres/min. The duration of Ihe lest will be determined at 1 min/m" of the surface area under test, subject lo a minimum of 3 minuies. 

Test duration at 1 min/m of the surface area under test, subject to a minimum of 3 minutes. After the le.st, there will be no penetration of water inside the enclosure. 

The test is carried out by completely immersing the test enclosure in water so that the head of water above the lowest portion of the enclosure is a minimum 1 m, while the highest portion is a minimum 150 mm. Duration of the test will be 30 minutes. 

After the test there must be no penetration of water inside the enclosure. 

The enclosure must be tested for one minute, with an inside air pressure equal to a head of about 1 in of water. No air should leak during the lest. Air leakage may be detected by submerging the enclosure in water, with the Just covering the enclosure. 

Construction and verification test of flameproof enclosures of electrical apparatus 2148/1993 BS 4683-2/1993 5501-5/1997 -... 

Type tests are conducted on the first enclosure of each voltage, current rating and fault level to demonstrate compliance with electrical and constructional design parameters. The tests provide a standard reference for any subsequent enclosure with similar ratings and constructional details. The following tests may be conducted to demonstrate verification of the following ... 

The ambient temperature should be measured during the last quarter of the test by at least three thermometers or thermocouples placed equally around the switchgear assembly, at almost the centre level and at about I metre from the body of the enclosure. The ambient temperature to be considered must be the average of these readings and should be within 10-40°C. To ensure that the ambient temperature is unaffected by ntagnetic field, alcohol thermometers must be used and not mercury thermometers. 

This test is applicable to all outdoor metal-enclosed switchgear and controlgear assemblies, as in lEC 60298, lEC 60694 and ANSI C-37/20C. The enclosure to be tested should be complete in all respects including its mounts, bushings (for HT switchgear assemblies, 1 kV and above) and wiring. One or more vertical units can be tested simultaneously as may be convenient, but not more than 3 m panel width can be tested at a time. For a multiple unit switchboard, however, at least two vertical units should be tested together to check the joints between the units. 

All surfaces of the enclosure must be tested uniformly for 5 minutes each. The water will be impinged on the surface of the enclosure from a distance of not more... 

Enclosure for electrical equipment up to lOOOV. Test criteria and design tests Industrial controls and systems. Enclosures... 

---