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Fire Alarm -- Maintenance

This is the original drawing made by the architect and corrected by the fire alarm installer. The corrected drawing is the As-Built
Photo Courtesy Integrated Fire & Security
Here, the original drawings made by the design engineer have been corrected by the fire alarm installer as the installer built fire alarm system. These as-builts will be redrawn at the shop before being turned over to the building owner.
Douglas Krantz -- Fire Alarm Engineering Technician, Electronic Designer, Electronic Technician, Writer

Are As-Built Drawings Available When Needed?

By Douglas Krantz

When available, as-built drawings are used by architects and engineers for remodeling or for designing new additions to the building. They're also used by service technicians when determining the layout of the fire alarm system.

As-Built Drawings Made During Installation

To document the installation, at least nowadays as they build a fire alarm system, installers are the ones that produce an as-built diagram.

When troubleshooting, once the building is finished, these drawings are available to the service technician to see layout of the fire alarm system. At least that is the intention of the NFPA Code.

Problem Getting the As-built Drawings for Troubleshooting

Architects and architectural engineers consider the as-built drawings to be very important, and they're under the impression that these drawings are always available to the people servicing the building.

In reality, for the technician arriving on site to service the system, the as-built drawings are rarely available; there are just too many individual reasons for these drawings to be accessible:
  1. The drawings are at the shop, but the technician just doesn't have time to drive across town, find the drawings at the shop, and then return to fix the fire alarm system.
  2. The building is older so the drawings were never made in the first place.
  3. The wiring layout in the new fire alarm system is from the old system, and the as-built drawings for the old system were never made.
  4. The original drawings were made by a different fire alarm service company so the current service company doesn't have the drawings.
  5. The building has been remodeled or the system has been added to many times, but the original as-builts were never upgraded.
  6. The on-site drawings aren't available because:
    • The drawings may be on site, but:
      • They're buried in a huge pile of other drawings and it will take hours to locate the right one.
      • They're stored in a locked room that no one on site has access to.
    • They were on site at one time, but are now lost.
    • The drawings were originally turned them over to the contractor, who turned them over to the owner, who didn't turn them over to the building engineer.
    • The building never had storage space for drawings - older and mid to small apartment buildings, retail stores, small office buildings, all fall under this category.
    • The drawings on site are architectural drawings and don't show how the fire alarm system was installed.
  7. The drawings that are available are now so fragile that if they're even unrolled, the paper tears apart.
  8. Etc.
Even as the building is remodeled, rarely is anyone on site keeping up the as-built drawings. When someone is keeping up these as-builts, the drawings usually only show building plans and almost never include the fire alarm system wiring.
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Troubleshooting Without As-Builts

It goes without saying that from time to time the fire alarm system breaks down and requires troubleshooting. For the technician, to speed up the troubleshooting process, the as-built drawings would be very helpful.

The thing is, unless there is a big change in the method of producing and distributing the as-builts to the technician, the only accessible as-built drawings available for troubleshooting will reside in the head of the service technician. These head-based as-builts will be assembled slowly over time, as the technician discovers the system wiring during regular service to the fire alarm system.


Douglas Krantz

Describing How It Works

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Electrical Flow

On this website, most references to electrical flow are to the movement of electrons.

Here, electron movement is generally used because it is the electrons that are actually moving. To explain the effects of magnetic forces, the movement of electrons is best.

Conventional current flow, positive charges that appear to be moving in the circuit, will be specified when it is used. The positive electrical forces are not actually moving -- as the electrons are coming and going on an atom, the electrical forces are just loosing or gaining strength. The forces appear to be moving from one atom to the next, but the percieved movement is actually just a result of electron movement. This perceived movement is traveling at a consistent speed, usually around two-thirds the speed of light. To explain the effects of electrostatic forces, the movement of positive charges (conventional current) is best.

See the explanation on which way electricity flows at