Section 1261.3 - Requirements for interlocks(a)General. For all clothing storage units with interlocks, including consumer-assembled units, the interlock components must be pre-installed, and automatically engage when the consumer installs the interlocked extendable element(s) or door(s) in the unit. All interlocks must engage automatically as part of normal use.(b)Interlock pull test.(1) If the unit is not fully assembled, assemble the unit according to the manufacturer's instructions.(2) Place the unit on a hard, level, and flat test surface.(3) If the unit has one or more levelling devices, adjust the levelling device(s) to the lowest level; then adjust the levelling device(s) in accordance with the manufacturer's instructions.(4) Secure the unit, without interfering with the interlock function, to prevent sliding or tip over.(5) Open any non-interlocked doors that are in front of the interlocked extendable elements.(6) Engage the interlock by opening to the maximum extension the number of extendable elements or doors necessary to engage the interlock.(7) Gradually apply over a period of at least 5 seconds a 30-pound horizontal pull force on each interlocked extendable element or door at the center of the pull area(s), one element at a time, and hold the force for at least 10 seconds.(8) Repeat this test until all possible combinations of extendable elements and doors have been tested.(c)Performance requirement. The interlock will be disabled or bypassed for the stability testing in § 1261.4(c) if, as a result of the testing specified in paragraph (b) of this section: (1) Any interlocked extendable element or door extends during the test without retracting the originally open extendable element or door; or(2) Any interlock or interlocked extendable element or door is damaged or does not function as intended after the test.