Why LED Fixtures?

LED fixtures are gaining popularity for landscape lighting because of better light performance, low energy consumption, and variety of light temperature options. The California Energy Commission updates the Building Energy Efficiency Standards (Title 24) to reduce energy consumption in new and existing buildings. The most recent update mandates that all residential new construction applications require high-efficacy lighting, making LEDs essential for hardscapes. Here are some important questions to consider if you’re thinking of installing or upgrading your customers’ to LED fixtures and lamps.

How can I diagnose and fix an LED fixture short?
Shorts occur when electricity arcs within the system. The direct burial wire used to power lighting has 2 wires, and arcs happen when the currents passing through these wires touch each other. There are a multitude of reasons for this, but a few common ones are a poor wire connection, use of the wrong outdoor connection system, a cut or frayed wire, moisture damage within the system, and places where wire is stretched over roots and rocks. You’ll also want to look for broken filaments and yellow colored LED diodes, which indicate lamp burnout.

If all your lights are out, this is probably an easy fix. Check and reset the breaker in your customer’s transformer. If this does not fix the issue and there’s no power to the transformer, check the GFCI outlet on the circuit. Reset this, then try resetting the breaker again. If the outlets are working, check the voltage and amperage- the transformer could need to be replaced. Ensure wires entering the transformer are inside the terminal lugs and tightened, as these wires could potentially arc off each other. If customers have a photocell within their transformer that is another thing to check; bypass this and try again. If the lights are working, you’ll need to replace the photocell. You can also use your voltmeter on individual fixtures to check power to specific fixtures, which is a good way to track a short.

If some lights work and others don’t within a well-built system, this is typically due to lamp burnout and you can simply replace the LED lamps. However, if that does not work, check the connections next. Connections that slide can loosen, pull at the wire, and allow moisture in, causing damage. If this is the problem, consider switching the system to copper crimps or heat shrink connections, as these work more efficiently. After checking the lamps and connections, ensure the sockets are high grade and the seals are intact. If the seals are broken, the sockets could have moisture damage and you should replace them.

If a section of lights is out in a certain area, it indicates that a run has been cut off a circuit. If you’ve tried all of the above and the lights continue to trip, it could mean a cut wire is the issue and will need to be replaced.

How many lights can I put on one line of wire?
The number of lights on a circuit depends entirely on the load of the fixtures. An analysis should be completed to calculate the voltage drop. Voltage drop should stay within the manufacturer’s design limits. The more fixtures you add to a run, the more the voltage is reduced. The National Electrical Code states that a circuit cannot supply more than 80% of the circuit breaker’s limits. Ensure the voltage is consistent throughout the line and distributed evenly, avoiding “daisy chaining,” or connecting light fixtures from one to the next on a single circuit, as this makes it difficult to get enough power to the lights at the end of the line.

Wire runs should be split down the middle and fed through the center to avoid voltage drops. Another way to avoid these drops is to use a multi-tap transformer with multiple output voltages, ranging from 12-15V, to accommodate larger wire runs. Check your manufacturer’s design specifications to ensure that wiring and transformer size align with your project's needs.

Using LED lamps can help as their drivers allow a range of voltage loads. However, you’ll still want to match the suggested voltage as best as possible to not shorten their lifespan.

Use a voltage meter to check each light fixture in the run before completing your work to ensure each fixture receives the correct voltage. Check your lamps and fixtures for wattage and voltage information and ensure you have the right tools for the job or visit your local SiteOne branch today.