IEEE C37.41-2008 pdf free download – IEEE Standard Design Tests for High-Voltage (>1000 V) Fuses, Fuse and Disconnecting Cutouts, Distribution Enclosed Single-Pole Air Switches, Fuse Disconnecting Switches, and Fuse Links and Accessories Used with These Devices.
4.5 Acceptance criteria
The successful completion of tests listed in this standard requires that various criteria be met, including the following:
a) A device shall perform all of its intended functions. While it is not feasible to list all possible device functions, typical examples are that devices intended to drop down, drop open, or initiate operation of other devices after current interruption shall perform these functions in their intended manner on all interrupting test series (see NOTE 2). b) A filled current-limiting fuse shall not emit filler material or flame during interrupting tests, although a minor emission of flame from a striker or indicating device is permissible, provided this does not cause breakdown or significant leakage to ground.
c) Fuses that operate an indicating device need not comply with any specific requirements but shall visually and fully operate. If a current-limiting fuse includes a device, the only function of which is to provide indication of a fuse operation, and that indicator does not operate, then although the fuse has failed to pass the test as a fuse with an indicator, the test may be used as part of a series to demonstrate that an otherwise identical nonindicating fuse has met the requirements of the standard.
d) After an interruption test, all parts of the device shall be in proper position, and the fuse shall be removable from its support in one piece as intended. In addition, after replacing parts that are normally field replaceable (see NOTE 1), excluding a fuse holder, the condition of the device shall be as follows:
e) Mechanical requirements: In substantially the same condition as at the beginning of the test. Depending on the current interrupted during interrupting tests, it is acceptable for the bore of expulsion devices to have some amount of erosion.
f) Electrical requirements: Capable of carrying rated current continuously at the rated maximum voltage. If there is evidence to suggest the device may not be able to carry rated current continuously because of contact deterioration, a temperature-rise test shall be performed using the maximum size fuse link, fuse unit, or refill unit. This temperature-rise test shall be performed on the device at rated current for the time it takes for the temperature to stabilize. Temperatures reached by the device may be higher than those achieved by a new device. The criterion for acceptability is long-term temperature stabilization.
g) Dielectric requirements: If there is evidence of insulator contamination from the test, a power- frequency dry-withstand test shall be performed at 75% of the normal test value for the device. After certain groups of tests, as specified in Table 7, Table 8, Table 11, and Table 19, the fuse holder may be changed. The acceptance criteria e) through g) are to be met with the fuseholder that has just been tested, even though it may not be suitable for any additional testing.
NOTE 1— Examples of parts that are normally field replaceable include replaceable fuse links, fuse units, refill units, expendable caps, and exhaust-control devices. Requirements of individual tests may limit the replacement of some parts until certain tests, or groups of tests, have been completed.
NOTE 2— The location of the lower test conductor relative to the fuseholder of a fuse or fuse cutout may, on some tests, influence its dropout characteristics by interfering with the movement of the fuse link leader (the flexible conductor used to complete the electrical circuit between the fusible element and the lower fuseholder contact). The manufacturer’s recommendations for conductor placement relative to the tested device should therefore be followed.
4.6 Test-conductor dimensions
4.6.1 Interrupting, load-break, and short-time test conductors Electrical connections shall be made by a bare conductor connected to each terminal of the device being tested. These conductors shall be of sufficient size to carry the test current adequately for the anticipated time. The source side lead shall be connected to the upper terminal of the device and the return or load side lead to the lower terminal, unless normal service conditions, manufacturer’s recommendations, or other IEEE Std C37.41 clauses require that the connections be reversed or that the device be mounted horizontally. For general-purpose and full-range current-limiting fuses, test series 3 tests (long-time melting tests) shall use conductor sizes as specified in Table 2, unless the manufacturer specifies a different conductor size due to the typical application.IEEE C37.41 pdf download.