93. A company advertises a "Romex 3 Conductor Splice Kit" which has been used in the past for connecting power in sections of a modular home. This company is now also claiming that these splice kits can be used in remodeling work in an existing house and be buried in the wall per "Article 334-40b" (their exact terminology). The UL listing category appears to be QAAV, which in the brief description in the White Book indicates that these must be capable of withstanding"... mechanical shock that might occur while transporting the units in which they are used." which would seem to indicate their use is for the modular home connections and not for burial in a wall. Is this the correct listing for the product? Can they be buried in a wall?
As the question states that these NM cable and splice kits are Lsited under the category Non Metallic Sheathed Cable Interconnectors (QAAV), located on page 240 in the 2007 White Book. This category covers self-contained interconnectors employing pressure cable connectors, insulation displacement or insulation piercing connectors for splicing or tapping nonmetallic (NM) sheathed cable. These interconnectors are intended for installation in accordance with ANSI/NFPA 70, "National Electrical Code."
These devices have been investigated for equivalency to Type NM cable in insulation and temperature rise, and for capability to withstand fault currents, vibration and mechanical shock that may occur during transport of the units in which they are used.
300.15 Where boxes or fittings are required, (H) Insulated Devices As permitted in 334.40(B), a box or conduit body shall not be required for insulated devices supplied by nonmetallic-sheathed cable.
334.40 (B) Devices of Insulating Material Switch, outlet, and tap devices of insulating material shall be permitted to be used without boxes in exposed cable wiring and for rewiring in existing buildings where the cable is concealed and fished. Openings in such devices shall form a close fit around the outer covering of the cable, and the device shall fully enclose the part of the cable from which any part of the covering has been removed.
These interconnecors are insulating devices equivalent to NM cable and can be installed in accordance with Section 33.40(B), so if is being used for rewiring in existing building, it can be concealed and fished.