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SPECIFICATION 55PC, ISSUE 8

NOTE:

ANY PRINTED COPY OF THIS DOCUMENT

IS AN UNCONTROLLED COPY.

© 2008-2015 Tyco Electronics Corporation. All rights reserved.

the air inlets. The burner shall be adjusted to furnish a 3-inch (76-mm) high conical flame

with an inner cone approximately 1 inch (25 mm) in length and a flame temperature not less

than 954°C at its hottest point, as measured with an accurate thermocouple pyrometer. A sheet

of facial tissue conforming to UU-T-450 shall be suspended taut and horizontal 9.5 inches

(241 mm) below the point of application of the flame to the specimen and at least 0.50 inch (13

mm) from the chamber floor, so that any material dripping from the specimen shall fall upon

the tissue.

4.6.7.2

Test Procedure

A 24-inch (610-mm) specimen shall be marked at a distance of 8 inches (203 mm) from its

lower end to indicate the point for flame application and shall be placed in the specified 60-

degree position in the test chamber. The lower end of the specimen shall be clamped in

position in the specimen holder and the upper end shall be passed over the pulley of the holder

and the applicable weight shall be attached. For wire, the weight shall be equal to one half the

test load specified for the crosslinked verification test of the same wire in Table 4. For cable,

the weight shall be sufficient to hold the specimen taut throughout the test. With the burner

held perpendicular to the specimen and at an angle of 30 degrees from the vertical plane of the

specimen (see Figure 1), the hottest portion of the flame shall be applied to the lower side of

the specimen at the test mark. The period of test flame application shall be 30 seconds and the

test flame shall be withdrawn immediately at the end of that period. The distance of flame

travel upward along the specimen from the test mark and the time of burning after removal of

the test flame shall be recorded; also the presence or absence of flame in the facial tissue due

to incendiary dripping from the specimen. Charred holes or charred spots in the tissue shall be

ignored in the absence of actual flame. Breaking of the wire specimens in size 24 or smaller

shall not be considered as failure, provided the requirements for flame travel limits, duration

of flame, and absence of incendiary dripping are met.

FIGURE 1. FLAMMABILITY TEST APPARATUS

(shown without chamber)