Frequently Asked Questions – LED Systems

Here are the most FAQs for the CS Professional Series LED Landscape Lighting Systems. Please submit specific questions to support@pmlighting.com.

Q. How many lights can I add to each cable on the transformer?

A. The number of lights you can add to each cable run varies depending on the type of fixtures being added and the length of the Main Supply Cable. Luminaires with lower watt bulbs allow more fixtures to be added while luminaires with higher watt bulbs will decrease the total number of fixtures you can add. Also, the longer the distance of the Main Supply Cable used for the run, the lower the total wattage that will be available for fixtures. Because of these variables, you should design your system using at least 2 different Main Supply Cable runs for each set of transformer terminals to balance the load.

For transformers up to 300 watts there will be one (1) set of terminals (left and right) and for the 600 watt transformer, there will be two (2) sets of terminals (L,R & L,R). Do not exceed the maximum wattage for each set of terminals, up to 100 watts for the 100 watt transformer and up to 300 watts for the 300 and 600 watt transformers.

Q. Why does the length of the Main Supply Cable matter for total wattage?

A. In Low Voltage applications, the landscape lighting cable generates resistance on the circuit which consumes wattage that would otherwise be available for additional luminaires. Most professional landscape lighting installers recommend limiting the total wattage of luminaires on a transformer to 80% of the unit’s power rating to compensate for this additional wattage requirement. This 80% Rule is taken into consideration along with Voltage Drop in the Easy Design Chart so you do not have to worry about calculating these complex scenarios.

Q. What is “Voltage Drop”?

A. Voltage Drop is the effect on the final voltage at the luminaire based on the length of the Main Supply Cable as well as the gauge of the cable and total wattage on the cable. Heavier gauge cable helps to minimize this loss of voltage at the luminaire. Voltage drop occurs more readily on halogen systems since the wattages of the halogen bulbs is much greater than LEDs. Also, LEDs operate within a voltage range (often from 8 – 18V) so they will effectively light the same as long as the incoming voltage to the luminaire is within the range. On the other hand, halogen lamps will begin to turn more amber in color and dim as the voltage decreases so careful attention must be given to ensure there is not more voltage drop on a single run than is needed to power each run of fixtures.

Q. What gauge cable should I use when installing my system?

A. The CS Professional Series LED systems come complete with heavy duty professional 14 gauge direct burial cable. We do not recommend using any cable that is lighter than 14 gauge for our LED systems. For extremely long distances, you may desire to use a heavier 12 gauge cable but this is typically not needed as long as the Easy Design Chart outline is followed. Unlike the original CS9300 halogen system, the CS Professional Series LED systems do not require the use of T-Connectors or the T-Connector Cable since the LEDs are designed to operate in a voltage range and will not experience the extreme voltage drop issues, making this system on of the easiest systems to install. Simply run two (2) main supply cables from the transformer and connect the fixtures on to the 14/2 cable as needed..

Q. What do I need to add lights on my basic system?

A. The CS Professional Series Landscape Lighting Systems come complete with everything needed to install the luminaires included in the kit. This includes the 100 watt Pro-Series Transformer, which has ample power to double the size of your system if needed. when using the 80% Rule. If you want to add more fixtures to your system beyond the capacity of the 100 watt transformer, you will need to add another power transformer to increase your system’s capabilities. Additional transformers, luminaires, and accessories are available from our approved retailers or online store. To help calculate the number of fixtures you can have on the 100 watt transformer, add up the total wattage of each fixture to be installed. The CS936-LED Path Lights and CS938-LED Deck Lights are only 3 watts each. The CS937-LED Bullet Lights are only 5 watts each. The CS933-LED Well Lights are 9 watts each.

Q. How much electricity will my landscape lighting system use each month?

A. This varies by location depending on local electricity rates but on average, a 100 watt transformer fully loaded and running 6 hours each night costs only about $2.07 per month for electricity. This system uses 80% less electricity when compared to line voltage lighting making low voltage LED landscape lighting one of the best choices in energy efficiency. This energy efficiency characteristic coupled with sustainable solid copper fixtures makes the CS Professional Series LED systems one of the most environmentally friendly choices available today.