Running Wires

Even in this wireless world, locksmiths must run wire for access control installations. This guide to wiring and tools helps select and install the right product.

It might be a wireless world, but today’s locksmith still runs a lot of wire. Wiring is needed for video systems, electronic access control, intercoms, alarm systems and IP-based video and access control.

Aren’t wireless alternatives to these wired products available? And the answer is: if course there are wireless alternatives for many of these systems, but not all. And the additional expense of the wireless counterpart may not offset the perceived savings on wire and labor.

Standalone access control is not a one-size-fits- all solution for every installation. We do not go to a prospective client’s premises with the any preconceptions except that we will be closing a sale. We specify what will best serve the client’s needs.

For example, if a client wants a door control system, choices include maglock, motion and REX. If a client wants a delayed egress system, again this must be wired. Even a wireless alarm system requires at minimum, wiring to a wall mount transformer for power, and a wiring to a telephone (or DSL) jack.

So the conversation is not so much whether to wire it or not but rather to refine the conversation to what type of wire to use and how best to install it.

Types Of Wire

Plenum Rated: Plenum is the open space found above a building’s dropped ceilings, and it is often used for air circulation in heating and air conditioning systems.

Plenum spaces are often used to run wiring. Article 800 of the National Electric Code (NEC) says cable used in plenum spaces must be Plenum-rated.

Cable which is to be run between floors in non-plenum areas is rated as riser cable. The fire requirements on riser cable are not as strict. Plenum cable can always replace riser cable, but riser cable cannot replace plenum cable in plenum spaces.

Article 800 of the National Electrical Code (NEC) states that plenum cables must comply with the specifications for flammability and smoke density outlined in Underwriters Laboratories (UL) and National Fire Protection Association (NFPA) testing methods.

Plenum-rated cables are distinguished from other types of cabling by the special types of plastics used in their jackets which are flame-retardant, low smoke materials such as polyvinyl chloride (PVC), fluorinated ethylene polymer (FEP), or a polyolefin. These plastics offer good resistance against fire, and in the event that they do begin to burn, they will not emit large quantities of harmful fumes.

Consider that damaged ductwork in a dropped ceiling can result in the space above the tiles will inadvertently become a plenum, and will therefore serve as a conduit for toxic fumes from burning wire in a fire.

So for highest fire safety it is best to assume all drop-ceiling airspaces are plenums, whether or not they are officially designated as one.

Non-Plenum Rated generally describes cabling designed for interior use.

Direct Burial: Direct burial cable is designed to be run in a trench underground without the use of conduit to surround it. The electrical wires are encased in a thermoplastic sheath that seals out moisture and protects the wires within.

Solid Conductor: Wire is a single conductor, as opposed to stranded.

Stranded: Many strands are wrapped together to form a conductor. Because solid wire is more rigid and is likely to fatigue and break if bent stretched or flexed, solid wire is avoided in most low voltage work.

Shielded: Cable has a metallic cover wrapped around the inner conductors but within the outer protective jacket. In some situations the shield is incorporated as one of the conductors but in others, it is attached to a system or earth ground and is used to protect the inner cables from radiated electrical noised from adjacent wring and machinery in the structure.

UTP: Refers to unshielded copper wires that are twisted around each other to decrease crosstalk or electromagnetic induction. The twist in UTP helps to reduce crosstalk interference between wire pairs. Every signal on a twisted pair involves both the wires.
The term UTP often refers to an alternative means of transmitting video surveillance camera signals.

This content continues onto the next page...

We Recommend