CAST Landscape Lighting System Calculator (Version 1.03)
Introduction
The CAST Landscape Lighting System Calculator is an html-based, javascript
driven, online calculator meant for three purposes:
- Pre-installation planning tool. After scoping out a new project, the architect, designer or installer can take preliminary system information and, using the calculator, determine wire sizing and transformer selection for minimizing voltage loss and optimizing system performance.
- Sales Support. With use of the tool's Energy Cost Calculator the architect, designer or installer can provide a fairly accurate approximation of the system's operating cost as well as an estimation of the cost savings (compared to high voltage).
- Learning tool. The calculator has a sophisticated validation programming to detect any system design errors that include: exceeding amp rating of wire, exceeding wattage constraints on transformer commons, selection of transformers insufficient for the job, and so on. The calculator displays error messages with specific instructions on how to correct the errors.
Computer System Requirements and Troubleshooting
The calculator works on both Mac's and PC's in all common operating environments. It functions best in newer versions of Internet Explorer, Netscape Navigator and Safari. Since Javascript functionality is used, it will not operate in browsers where Javascript has been disabled. The calculator also uses pop-up windows to display error messages. These messages may not display if a pop-up blocker is being used. Since this calculator contains nearly 2,000 lines of code, there may be brief time delays after entering data. These delays may be shortened by closing other windows in the browser and by exiting other programs that may be running.
Using the Calculator
The calculator is designed to allow you to record wire run information and transformer specifications for each transformer in an installation. If the project requires more than one transformer, then each transformer must be calculated separately. The "Print" button at the bottom of the form allows you to retain a record of the calculated results.
Line Voltage
All Landscape Lighting Transformers do not "regulate" voltage, they only step it down as a percentage of incoming line voltage. If the line voltage at the GFI outlet is 120V then the 12V tap will deliver 12V. If the input is 115V then the 12V tap will deliver 11.5V. Keep in mind that line voltages may change on a seasonal basis and that energy use in the household may also affect the incoming voltage.
Wire Selection
Wire is selected based on code-specified maximum amperage loads, optimal voltage loss and suitability for the system as a whole. The vast majority of projects are well served with use of 10 gauge or 12 gauge wire. Our seminar leaders suggest selecting 10 gauge as the first choice since it is priced only slightly higher than 12 gauge but will accommodate 50% more amperage. The following flow chart is a good guide for wire selection.
Total Watts (Lamps and Wire)
This value includes wattage contribution from the lamps, the 25 ft. 16/2 fixture lead wires and the homerun wire.
Transformer Selection
The transformer selector allows you to select one of the CAST Lighting transformers and to ensure that the transformer is appropriate for the job at hand. The following is a chart that shows in-a-glance all the CAST transformer specifications.
|
Model |
Watts |
Taps (Volts) |
Enclosure |
Extra Common |
| MASTER SERIES™ | ||||
CM1500SSMT |
1500 |
12, 13, 14, 15, 16, 17 and 18 | Stainless Steel |
Yes |
CM1200SSMT |
1200 |
12, 13, 14, 15, 16, 17 and 18 | Stainless Steel |
Yes |
CM900SSMT |
900 |
12, 13, 14, 15, 16, 17 and 18 | Stainless Steel |
Yes |
| JOURNEYMEN SERIES™ | ||||
CJ900PSMT |
900 |
12, 13, 14 and 15 | Powder Coated Steel |
No |
CJ600SSMT |
600 |
12, 13, 14 and 15 | Stainless Steel |
No |
CJ600PSMT |
600 |
12, 13, 14 and 15 | Powder Coated Steel |
No |
CJ300SSMT |
300 |
12, 13, 14 and 15 | Stainless Steel |
No |
CJ300PSMT |
300 |
12, 13, 14 and 15 | Powder Coated Steel |
No |
| POWER PRO SERIES™ | ||||
CP1200SSMT |
1200 |
12, 13, 14, 15, 16, 17, 18, 20 and 22 | Stainless Steel |
No |
CP900SSMT |
900 |
12, 13, 14, 15, 16, 17, 18, 20 and 22 | Stainless Steel |
No |
Energy Cost Calculator
This part of the calculator is primarily a sales tool. It enables the architect, designer or installer to estimate the operating cost of the system.
Note: the default value for "Cost per KWH" will not be accurate. For an accurate calculation, replace this default value ($0.15/KWH) with the correct value obtained from the client's electric company. For more accuracy, electrical delivery charges and applicable taxes could also be added.
The calculator also provides an estimate on the savings per year compared to an equivalent high voltage system. This savings figure is based on an oft quoted equation: low voltage electrical cost = 1/3 high voltage electrical cost. This equation takes into account the higher light output/watt delivered by low voltage quartz/halogen and other 12 volt lamps compared to 120 volt incandescent or other flood type lamps. It also assumes that a low voltage lighting design aims to provide a broader coverage of low level lighting compared to the higher intensity flood or spot lights in the typical high voltage design. A more accurate estimation could be made by an actual calculation based on high voltage lamps replaced by low voltage lighting in each project. To make such a calculation, use the following formula:
((old high voltage watts) – (new low voltage watts)) x (KWH cost from electric supplier) x (hours of operation per day) x 365 = Savings per year
Printing Support
There is a known problem with the calculator not printing on one page;
instead, it flows over two pages. It may also exceed the side margin width.
The way the calculator prints is dependent on the printer settings that
are unique to every printer. It is also affected by the page set-up that
is unique to your operating system. Here are some suggestions (terms and
navigation may vary depending on opeating system and browser):
- While the calculator is open in your browser, go to "File"/"Page setup".
- Adjust margins to zero or minimum value allowed.
- Click Printer (bottom right of Page setup dialogue box)
- Click Effects tab, then select Print Document On and Scale to Fit If you donÍt have the above options then type in 90 in the % of Normal Size box. You may need to alter this % if the document still doesnÍt fit on one page. These options may not be available for all printers.
Support
Your questions and comments are welcome. E-mail us or call (800) 914-CAST.