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Creating
and Designing a landscape lighting system to deliver consistent
results and reliability from project to project requires a uniform
approach based on proven techniques, processes, and experience.
At InVista Lighting Design we employ the InVista
Method which has been adopted from the CAST system of
installation.
David
Beausoleil, founder of CAST Lighting, spent years working
with lighting installers perfecting a system of installation.
This method is a significant improvement over prior inconsistent
methods and ensures a lighting system that performs optimally
and is easy to maintain year after year.
The InVista Method consists of
the following steps:
DESIGN
> PLANNING > INSTALLATION
> TESTING > DOCUMENTATION
DESIGN
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SET
OBJECTIVES |
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Together we discuss what can be reasonably
achieved with a lighting system within the constraints of
the budget. We write down all of the desired objectives. |
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WALK
THE PROPERTY |
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Walk the property, viewing from every angle
(including the approaching road.) First, we think about the
visual composition of the entire scene. We note what is beautiful
and distinctive about the property. We recognize features
of the landscape and structures, as well as, repeating patterns
and interesting forms. Next we determine focal points and
decide where you want the viewer's attention to be directed.
Then we pay attention to transition areas and apply the basic
elements of design to create a scene that satisfies your objectives. |
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PHOTOGRAPH
FIXTURE LOCATIONS |
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As we decide on the location of each fixture,
we will take digital photographs of each spot. These photos
are later used during our proposal presentation and installation
phase and will be superimposed with an image of the exact
fixture type, lamp wattage, and beam spread to be used at
specified locations. |
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ROUGH
SKETCH |
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Next, a rough sketch of the property is
made, labeling each of the important areas and features. In
addition, digital photographs of the project site will be
taken to support the sketch and better record the location
of the fixtures. Then we'll measure and estimate the distance
of each wire run, and check for the availability of 120V power
source for transformer. |
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PLANNING
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REQUIREMENTS |
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Working from the rough sketch, we use the
"Preliminary System Requirements Worksheet" to record
all the information needed to make the necessary system sizing
calculations. |
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WIRE
SIZING |
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Landscape lighting requires either #10/2
or #12/2 direct burial wire to connect transformers to spider
splices. The selection is based on wire run distances and
wattage of fixtures on each run. |
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TRANSFORMER
SIZING |
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Selecting the correct transformer(s)
is a two-step process.
- We determine the total load on the system. This can
be estimated by adding the total wattage of all lamps
designed into the system configuration.
- Then we select the transformer(s) based on the total
load using the manufacturers "Transformer Sizing
Guide". We will then select a transformer with a
capacity exceeding the numbers calculated, to allow for
future additions to the system.
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INSTALLATION
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FIXTURE
PREPARATION |
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After unloading all materials, the stakes
and stems are attached to the fixtures. Then we'll stage each
fixture at its proper location according to our drawings and
digital photographs taken during our Design walk-through.
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TRENCHING |
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Low voltage lighting wire requires a minimum
of 6 inches burial and can be run without conduits. This is
where our crew will use a slit trenching technique to dig
narrow trenches along each wire run and between fixtures and
spider splices. |
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RUNNING
WIRE |
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Starting at the transformer, a wire run
will be pulled from the spool to the spider splice. Each wire
run is then labeled at both ends with numbered wire markers.
Then we'll run the lead wire from each fixture to the nearest
spider splice wire junction. |
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LAMPING
FIXTURES |
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The fixtures are now installed into the
ground. In doing so, each fixture is lamped with the correct
bulb according to type, wattage, and beam spread. The lamp
box is left at the base of the fixture so that we can record
the above data when we punch the "Fixture Record Tag"
at the end of the installation. |
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VOLTAGE TESTING
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CONNECT
ALL WIRE RUNS TO 12V TAP |
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After all spider splices are connected
and lamps installed, we return to the transformer and connect
all wire run leads to the 12V terminal so that we can establish
a voltage baseline. |
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TEST
FIELD VOLTAGES |
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Using a digital multimeter, we test the
voltage at each spider splice junction (or fixture) and record
the values on the project's "Field Voltage Adjustments"
form. Then we'll complete the form and our voltage loss calculations
to arrive at the taps needed to adjusted the voltages to the
acceptable lamp operating range. |
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CONNECT
WIRE RUNS TO ADJUSTED TAPS |
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After calculating the correct taps for
each run, we return to the transformer and connect the wire
runs to their appropriate voltage tap. |
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RETEST
FIELD VOLTAGES |
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After connecting to the correct taps
and powering up the transformer, we retest the voltage at
each spider splice to ensure that all lamps are receiving
between 10.8 and 12 volts.
Since there is some voltage loss between the spider splice
and the fixture through the #16/2 lead wire, the correct
voltage at the spider splice is between 0.3 and 0.8 volts
greater than at the lamp. The extent of this difference
depends on lamp wattage. If necessary, we'll change the
taps until all readings are within the acceptable values. |
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FINAL
AMPERAGE MEASUREMENTS |
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To thoroughly check the system and to arrive
at the final amperage readings, we'll use a digital clamp-on
amp/volt multimeter. All readings from the voltage taps and
primary are recorded on the inside label of the transformer. |
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DOCUMENTATION
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RECORD
FINAL READINGS |
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In this last step of the InVista Method,
we'll complete the form on the inside lid of the transformer
using system information and final voltage and amperage readings.
A copy (digital photo) is also made for our records. This
permanent record is used in conjunction with the CAST Fixture
Record Tag to completely record all systems details. This
ensures that all future servicing and maintenance will be
trouble free. |
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MARK
FIXTURE RECORD TAGS |
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All of the Fixture Record Tags are now
stamped with the appropriate information. |
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FINISHING
THE PROJECT |
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After recording all system information
on the appropriate forms, stickers, and tags, the transformer
lid is secured and the project site is cleaned up.
We then return to the project site after sundown to power
up the system, make final fixture adjustments and enjoy
the beauty of this installation together with YOU! (Hopefully,
the coffee you brewed is ready at that point!) |
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