Case study: Wiring schools for the future
Educational facilities need flexible, cost-effective wiring solutions
As electrical and information systems evolve naturally over time, older buildings skew away from the occupant’s newer needs regarding the location of hard-wired data, line voltage receptacles, wireless access point outlets (or lack thereof), etc. It becomes very difficult to “future-proof” a building due to some obvious hurdles such as the client’s budget, shifting use for each space, unexpected technological advances or changes.
Oftentimes some amount of future use pathway or cabling can be added but it’s not ideal 10 to 20 years after the original install. One potential solution is to complete a “modernization” type project within the building.
A great example for this concept is educational facilities. These buildings often have a cost–sensitive client because the budget would consist of tax dollars or bond funding and in these installations, functionality typically overrides aesthetics. Given these circumstances, a surface–mounted combination raceway is a perfect solution to provide both information cabling and power wiring to specific locations.
Additionally, these combination type raceways can be used for projector media wiring to control stations and ceiling–mounted equipment vaults. These surface–mount raceways typically are mounted to the wall and routed horizontally to provide the ideal outlet locations and then a 90-degree transition is used to route the raceway into the ceiling. Once this is routed into the ceiling, the power wiring can be converted to MC or EMT (depending on site conditions) and routed to the nearest panelboard while the information cabling can transition to a cable tray or J-hooks to provide support for the intermediate distance.
It is critical to note that there should be a bushing or other type of protective end-piece at the end of the surface–mounted raceway to prevent cabling from coming in contact with a sharp sheet metal edge as it transitions to the J-hooks.
Additionally, when considering a modernization scope, it’s important to understand that the equipment in the head-end or main equipment room and intermediate telecommunications rooms will likely be changed out. This may result in an expansion of these spaces or, at the very least, reorganization of the racks and cabinets. This can result in the need for power wiring and ladder rack modifications within the room.
For these types of installations, it’s not recommended to provide power receptacles on the ladder rack itself because the ladder rack may be modified once the old cabling plant is removed. For these installations it’s often wise to use a shallow, steel over–floor type raceway. Several manufacturers make this type of product and provide specific junction boxes that will accommodate standard receptacle sizes and special receptacles such as National Electrical Manufacturers Association types L5-30R or L6-30R, and may provide wire fill to accommodate an L14-30R. This allows the client flexibility for rack or cabinet location within the equipment and telecommunications room spaces that is both cost–effective and convenient.