Meeting and Exceeding Water Exclusion Standards in Poke-Thru Devices and Floor Boxes

UL514A standards require that all concrete floor box covers and poke-thru devices meet a carpet water exclusion test. Water exclusion tests are designed to simulate typical maintenance procedures such as mopping tile floors and shampooing carpets.

UL recognizes that many carpets are shampooed frequently, resulting in a greater likelihood of scrub-water penetrating floor box covers and poke-thru devices. The new standard is designed to ensure that these products prevent water from entering electrical compartments.

This standard has significant implications for the specification community, as well as for building owners and facility managers. At present, only approved floor box covers may be used in tile applications; non-approved covers and all poke-thru devices are restricted to carpet applications. These wire and cable management systems have been redesigned to make them suitable for both tile and carpet. Additional benefits can be attained by exceeding minimum standards to protect communications compartments, as well as the required electrical areas of each device.

Water Exclusion Tests

Water exclusion testing for carpet and tile applications is performed with the device in the closed position (nothing is plugged in, and no wires or cables exit the device). In both tests, a mixture of soap and water is used. According to the standard, "Scrub-water shall not enter a floor box at the floor level through the box cover, cover flange, or other openings." [Note: the term "floor box" includes poke-thru devices.]

The test set-up is described in 32A.2.2:

"A floor box assembly is to be installed in a section of floor constructed to represent an installation as intended by the manufacturer. The cover plate is to be fully secured. Sealing compound is to be used around the perimeter of the floor box or cover flange to retain the soap solution on the floor assembly. A minimum 1/4-inch (6.3 mm) high dam is to be constructed around the floor assembly."

The test for tile applications is described in 32A.2.3:

"A scrub-water solution is to be prepared by mixing 4 tablespoons of floor cleaning soap with 1.0 gallon (3.79L) of water. The solution is to be poured over the cover plate of the floor box so that it collects to a depth of 1/8 inch (3.2 mm) above the floor assembly within 10 seconds or less. The solution is to remain on the floor assembly for one minute. The solution is then removed and the interior and under the cover of the floor box is to be examined for entrance of scrub-water."

The test for carpet applications is described in 32A.2.4:

"A scrub-water solution is to be prepared by mixing one tablespoon of floor cleaning soap with 1.0 quart (0.94 L) of water. The solution is to be poured over the cover plate of the floor box within 10 seconds or less. The solution is to run off the top and sides of the cover. The cover is then to be dried. The interior and under the cover of the floor box is to be examined for entrance of scrub-water."

Meeting the Requirements

There were two primary approaches to meeting the requirements of water exclusion tests: designing new parts to fit together more closely and incorporating gaskets in lids, covers, and other openings.

Poke-thru devices
Poke-thru devices feature multiple openings where water can enter. The primary design objective was to make these openings watertight within the parameters of the water exclusion tests. Further, Walker® poke-thru devices are distinguished by individual slide covers - a design improvement over older-generation flip lids - that snap in place over receptacles and data ports to prevent dirt and debris from entering the system. Reverting to flip lids and installing gaskets on them would have been a relatively simple solution, but customers appreciate the advantages of slide covers, including long-term durability and ease of use. Instead, engineers designed a specialized gasket that remains in contact with the slide cover at all times and in all positions. The gasket material provides the proper balance between water resistance and the ability to spring back into the closed position.

Concrete floor boxes
All concrete floor box covers were reviewed and redesigned with new parts that fit together more closely. While the covers of some floor boxes, such as smaller flip lids, were already approved for tile applications, others were not. These lids were fitted with gaskets that surround the lid when it closes. Of particular concern were large floor box lids that have cut-outs for wire and cable egress. Here, specialized gaskets were designed to fill these gaps, enabling the lid to meet water exclusion requirements.

Exceeding the Requirements

The standards require water exclusion only on the electrical side of a poke-thru device or floor box. (Under the revised standard, water will still be allowed to enter communications areas so long as it does not leak into the electrical side). Exceeding this requirement to exclude water from communications portions of the devices offers important benefits.

Although water entry into communications compartments is not considered a high risk for fire and/or shock, the presence of moisture can damage electronic components. A more practical advantage, however, is that gaskets that are designed to deter water also keep out dust and debris that can degrade the performance of sensitive electronic systems.

In the case of poke-thru devices, the slides that cover electrical receptacles are similar to those on communications ports, so it is possible to exceed the requirements and provide water resistance for all device compartments. Similarly, floor box covers also incorporate gaskets on cut-outs for communications cables.

Implications of Redesign

Greater specification flexibility
Redesigning poke-thru devices to meet the carpet water exclusion standard presented an opportunity to extend the use of these wire and cable management systems beyond carpet applications. The modifications mean that these devices can be used in either carpet or tile settings. Poke-thru devices that are currently installed can be modified to meet the new standard by replacing the device head. This may be especially attractive where replacing carpet with tile has been impractical due to the presence of existing poke-thru devices.

Specifiers who opt for concrete floor boxes have a greater degree of choice in the type of box and cover that is installed. Each floor box cover is suitable for either carpet or tile. Additionally, the new covers fit all existing installed flanges.

Aesthetics
Although the changes being brought on by the water exclusion standard may appear to be only functional, there are aesthetic considerations as well. Designers will be assured of uniformity since the same poke-thru device or floor box cover can be installed with carpet or tile.