Awaiting expert review. This page covers safety or regulatory rules that change over time. It is kept out of search results until a qualified reviewer has checked it; the sources below are dated so you can verify each point.
Quick answer
Low-voltage landscape lighting is a yard lighting system in which a transformer plugged into a household outlet steps power down to about 12 to 15 volts, and a cable carries that power to the fixtures.
The low-voltage side is the cable and fixtures. The supply side is still 120-volt household power, so the outlet, the GFCI and any new wiring are electrical work. Wire size and run length decide how bright the far fixtures are.
Quick facts
The key facts about Low-Voltage Landscape Lighting, with sources:
Key takeaways
- A low-voltage system is a transformer, a cable and fixtures. The transformer plugs into a covered, weatherproof, Class A GFCI outlet and may not be run on an extension cord.
- Add up fixture wattage and keep it under the transformer rating. Kichler says the total volt-amps should not exceed the transformer’s wattage.
- Long runs lose voltage. Manuals print how much: Toro’s says 35 VA drops 1 volt over 100 feet of 12-gauge, two-conductor wire.
- Wire sizes in this page are those printed in named manufacturer manuals for their own products. They are not a design. The product label and the electrical code your city adopted rule.
- New outlets, circuits and any line-voltage connection belong to a licensed electrician.
The part of the system that is not 120 volts
A transformer takes household current and lowers it. Iowa State’s extension writer put it this way: low-voltage systems operate off a 120-volt outlet and a power pack that lowers the current to 12 volts 5.
Modern transformers often offer taps from 12 to 15 volts, so installers can raise the starting voltage on long runs 14.
Those fixtures sit at the end of a cable that is buried shallow or laid under mulch. This is the common yard system. It is the same family described on the broader landscape lighting page, which also covers solar and line-voltage types and dark-sky choices.
Do not read “low voltage” as “no hazard.” The Volt manual calls low-voltage installation safe and low in shock risk, yet the same manual requires a GFCI-protected receptacle with an in-use cover and bans placing the unit near pools 3.
The transformer plugs into 120-volt power 1. That side is where the shock risk sits.
Wire gauge as one manufacturer prints it
| Total fixture wattage | 0 to 50 feet of wire | 51 to 100 feet | 101 to 150 feet |
|---|---|---|---|
| 0 to 50 watts | 16 AWG | 16 AWG | 14 AWG |
| 51 to 100 watts | 16 AWG | 14 AWG | 12 AWG |
| 100 to 200 watts | 14 AWG | 12 AWG | 12 AWG with the 15-volt tap |
Source and scope
From Ring’s Smart Lighting Transformer manual 2. The manual says to use the 15-volt tap only when the wire length is over 100 feet and total wattage is over 100 watts, and to use only UL or CSA approved low-voltage cable in common gauge sizes of 12 to 16 AWG.
The thinner the wire number, the thicker the wire: 12 AWG is thicker than 16 AWG.
Example: how far a 100-foot run falls short
Toro’s manual prints two rules of thumb: for LED loads use volt-amps in place of watts, and a given load drops 1 volt over 100 feet of wire.
The example loads below are invented. The rules are Toro’s, and the scaling in the last column is HyreYard arithmetic that assumes the drop grows in proportion to load.
| Wire, 100 feet | Load that drops 1 volt (Toro) | Example load | Drop for example load |
|---|---|---|---|
| 12/2 wire | 35 VA, or about 3 amps at 36 VA 1 | 36 VA | About 1 volt; Toro’s own example calls for the 13-volt tap 1 |
| 14/2 wire | 20 VA 1 | 30 VA | About 1.5 volts (30 ÷ 20) |
| 14/2 wire | 20 VA 1 | 20 VA | 1 volt |
| Kichler’s floor | Last fixture above 10 volts 4 | Start at 12 volts, 1.5-volt drop | 10.5 volts, above the floor |
Toro’s conversion for LEDs is lamp watts multiplied by 1.5 to get volt-amps 1. A 20-watt LED load is therefore about 30 VA.
The manual says to measure the voltage at the last fixture and move to a higher tap until it reads the target 1. Kichler also recommends confirming calculations with a voltmeter 4.
How voltage drop works, in plain terms
Wire resists the current that flows through it. The longer the wire and the more current it carries, the more voltage is lost before the power reaches the last light.
Kichler writes the loss as a formula: voltage drop equals two times the cable length times the total volt-amps on the run, divided by a cable constant 4.
The voltage at the last fixture is the tap voltage minus that drop.
A fixture that gets too little voltage runs dim or may not run.
Kichler sets a floor of more than 10 volts at the end of the run, and also a 9 to 15 volt operating range for fixtures on a wire run 4.
The two figures differ slightly in its own text, so ask the fixture maker for the range your lamp needs.
Installers have four levers. They can use thicker wire, shorten the run, split the load into two runs, or start from a higher tap.
Kichler lists a higher tap, fewer fixtures on the run and a heavier gauge as the fixes 4.
Toro’s third check is to adjust the transformer until the voltage at the point of connection reads 12 volts plus or minus 0.5 volts 1.
Drop = (2 × cable length × total VA on the run) ÷ cable constant
Cable length- One-way length of the run, in feet
Total VA- Sum of the fixtures on that run
Cable constant- A value for the wire gauge, given by the maker
Last-fixture voltage- Tap voltage minus the drop; Kichler says it should exceed 10 volts
The cable constant is not printed on the page we read. Use the maker’s chart or have an installer run the numbers.
Source: [4]
Where the term shows up: kits, plans and bids
You meet the term on boxes for plug-in kits, on a landscape lighting plan where a fixture schedule lists each wire run, and on a bid where a line says “transformer, cable and fixtures.”
A plan from a designer may show run lengths and loads. A kit box often shows only a wattage. Ask a bidder for the transformer rating, the total load and the wire gauge for each run.
For the design side, read the landscape design service page. HyreYard does not install lighting.
What low voltage does well, and where it falls short
What it can do
- Uses shallow, easy-to-bury cable. Volt’s manual says the main secondary wiring is for shallow burial under 6 inches, and Ring’s says to dig a trench up to 6 inches deep or cover the cable with mulch 32.
- Lets you add fixtures later, up to the transformer’s rating 4.
- Can be run on a timer or photocell. Toro lists timers, an astronomical timer and photocells among its accessories 1.
Where it falls short
Limits: the manual, the load and the site
A manual is binding for its product only. Ring’s wire chart and Toro’s drop rule do not carry to another transformer or to a different lamp.
Volt’s manual says it does not cover every variation in installation 3. Toro’s says the combination of its device and the rest of the system is for local inspectors to judge 1.
Sites add limits. Plants grow over fixtures. Soil settles and exposes cable. Water near the system raises the stakes.
Toro and Volt give 5 feet from a pool or spa and 10 feet from a fountain for the power unit, while Ring says 10 feet from a pool, spa or fountain 132.
Kichler says 10 feet from any pool or pond 4. Follow the manual that came with your unit.
Finally, a cable calculation is not a safety check. Kichler disclaims responsibility for misuse of its wire-size calculations and says to confirm with a voltmeter 4.
Stop at the outlet
Plugging a transformer into an existing covered GFCI outlet is the extent of a homeowner job in these manuals.
If there is no such outlet, the manuals say to contact a qualified or licensed electrician 12.
Do not splice into house wiring, remove the transformer cover on a live unit or make line-voltage connections yourself. Call 811 before digging.
What drives the bid
We do not publish prices. A low-voltage bid moves with the number and type of fixtures, the transformer size, the length and gauge of cable, the number of separate runs, the controls, and the digging through lawn, mulch or paving.
Adding a covered GFCI outlet adds electrical work. Splitting a long run in two can lower voltage drop but adds cable.
Lifespan depends on the fixture, the lamp, the weather and the upkeep, so we give none. Ask the bidder for the transformer rating, the planned load and the warranty terms. See the cost guide and the landscaping estimates guide for how to compare line items.
How an installation is laid out
The list below is the order the manuals follow, not instructions to wire a system. A homeowner may plug in a kit. An electrician is needed for any new outlet, any circuit and any line-voltage connection. Permits apply to new wiring in many places.
- Total the load. Add fixture volt-amps. Kichler says the total should not exceed the transformer’s wattage 4. Ring says to add the watts of each fixture 2.
- Choose the transformer spot. Near a covered GFCI outlet and above ground: at least 1 foot per Volt and Ring, and 12 inches per Kichler 324. Toro says 4 feet above grade and within 4 feet of the outlet 1.
- Pick the cable by length and load using your own product’s chart 2.
- Mark utilities with 811 before any trench.
- Run the cable in a shallow trench or under mulch 23. Use a connector rated for the job and keep joins sealed, as Toro’s system does with grease caps 1.
- Test voltage at the last fixture and adjust the tap 14.
- Total the loadFixture VA under transformer rating
- Place the transformerCovered GFCI outlet, off the ground
- Size the cableLength and load, per the product chart
- Dig safely811, shallow trench or mulch
- Test and tuneVoltage at the last fixture
Keeping the system working
- Check cable each year. Iowa State advises at least once a year for damage 5.
- Replace dead lamps. Iowa State notes a burnt-out bulb shifts the load to the rest 5.
- Keep the outlet cover closed on the cord, as Ring and Volt require 23.
- Re-test the last fixture’s voltage if you add lights, as Kichler’s load rule works only up to the transformer rating 4.
- Dig with care near beds and edges. See landscape edging for how edge work can cut cable.
Warning signs, and when to call an electrician
- A GFCI that keeps tripping.
- A transformer that is hot, buzzing, wet or cracked.
- Cut, exposed or chewed cable.
- Dim or flickering fixtures at the end of a run, which can be voltage drop 1.
- No covered GFCI outlet where you want the transformer 12.
- Fixtures planned near a pool, spa, pond or fountain 14.
Turn off power at the outlet and call a licensed electrician. Do not troubleshoot live line-voltage wiring.
What binds: labels, the electrical code and local rules
Three layers apply, and they are different kinds of rule. The first is the product label and manual.
Listed products carry installation instructions that are part of the listing, and Ring and Volt require UL or CSA approved low-voltage cable and CSA or local approval of the combination 23.
The second is the electrical code your city or state adopts, usually a version of the National Electrical Code. Toro’s manual says the NEC does not allow loading beyond 80 percent of a wire’s rating 1, and the NEC addresses lighting systems operating at 30 volts or less in Article 411.
We did not read the NEC, so we give no edition, section or table from it. The third is local ordinance, HOA rules and inspection.
A voluntary model code becomes law when a city adopts it, and editions differ.
As one example, the City of Geneva, Illinois lists the 2005 National Electrical Code among its adopted codes in a handout revised in 2020 6.
Another city may use a newer edition. Ask your building department which edition and amendments apply.
Wire burial depth and wiring methods are set by code and by the product’s listing.
Volt says its main secondary wiring is for shallow burial under 6 inches, and Kichler says burying its conduit 6 inches deep complies with the national electrical code 34. We did not verify those code claims against the NEC.
Low voltage compared with other yard lighting
| Type | What it is | Difference |
|---|---|---|
| Low voltage | Transformer, cable, fixtures at 12 to 15 volts 1 | Shallow cable; plug-in supply; voltage drop matters |
| Line voltage | Fixtures on 120-volt house wiring | Electrician, permit and inspection |
| Solar | Self-contained fixtures with a panel and battery | No cable, no transformer; output depends on sun |
| Smart low voltage | Transformer with an app | Same wiring rules; Ring’s transformer needs the same GFCI outlet 2 |
| Irrigation control wire | Low-voltage wire to sprinkler valves | A different system, though trenches may meet; see irrigation |
Low-voltage myths
- Myth Low voltage means no safety rules.
- Reality Toro, Ring and Volt each require a Class A GFCI-protected receptacle and ban extension cords 123.
- Myth Any wire works.
- Reality Ring says to use only UL or CSA approved low-voltage cable in 12 to 16 AWG, sized by length and load 2.
- Myth Add as many lights as fit.
- Reality Kichler says the total VA should not exceed the transformer’s wattage 4.
- Myth All fixtures on a run get the same light.
- Reality Voltage drops along the wire; Toro prints how fast 1.
- Myth A higher tap always fixes dim lights.
- Reality Ring says use the 15-volt tap only over 100 feet and over 100 watts 2.
Adopted code edition and inspection differ by place
The regional variable is the electrical code edition and amendments your jurisdiction has adopted, plus who inspects.
Geneva, Illinois, for example, lists the 2005 National Electrical Code in a 2020 handout 6. Burial depth, permits and inspection for yard wiring are set locally.
Ask your building department and read your HOA covenants before buying a system.
When low voltage fits, and what to do next
Low voltage fits a yard with an existing covered GFCI outlet, beds where cable can be buried or mulched, and a plan for modest runs. It fits less well where runs are long, loads are large or no outlet exists. A designer or installer can balance the runs.
The next step is to total your fixtures, find your outlet and read your transformer’s manual. Weigh installers with how to choose a landscaping company and see how we vet for what HyreYard checks. Mulch over cable is covered in mulch types.
- If Total load near the transformer rating
- Then Use a larger transformer or split the load 4
- If Anything touching house wiring
- Then Licensed electrician and local permit
Questions about Low-Voltage Landscape Lighting
What voltage is low-voltage landscape lighting?
Usually 12 volts, with some transformers offering taps up to 15 volts. The Toro, Ring and Volt manuals describe 12 to 15 volt systems, and Iowa State’s extension article describes a power pack that lowers the current to 12 volts. The transformer itself plugs into a 120-volt outlet.
Does low-voltage landscape lighting need a GFCI outlet?
Yes. The Toro, Ring and Volt manuals require a covered, weatherproof receptacle protected by a Class A GFCI, with an in-use cover. If you do not have one, they say to contact a qualified or licensed electrician. Extension cords are not allowed for the transformer.
What wire gauge should I use for landscape lighting?
It depends on length and load, and your manual decides. Ring’s chart lists 16, 14 or 12 AWG by wire length and total wattage for its transformer, and says to use only UL or CSA approved low-voltage cable in 12 to 16 AWG. Kichler suggests starting with 12 gauge and going heavier if needed.
What is voltage drop in landscape lighting?
It is the voltage lost along the wire. Long runs and big loads lose more, so far fixtures can run dim. Toro’s manual says 35 volt-amps drops 1 volt over 100 feet of 12/2 wire and 20 volt-amps does the same on 14/2. Kichler says the last fixture should stay above 10 volts.
How many lights can one transformer run?
As many as its rating allows. Kichler says the total volt-amps should not exceed the transformer’s wattage, and Ring’s example transformer tops out at 200 watts. Add the wattage of each fixture, and use volt-amps for LED loads as Toro’s manual describes. Check your own label.
How deep should landscape lighting cable be buried?
Follow your manual and local code. Volt says its main secondary wiring is for shallow burial under 6 inches, Ring says to dig a trench up to 6 inches deep or cover the cable with mulch, and Kichler says burying its conduit 6 inches deep complies with the national electrical code. Call 811 first.
Can I install low-voltage lighting myself?
Plugging a kit into an existing covered GFCI outlet is the homeowner scope in these manuals. New outlets, circuits and line-voltage connections need a licensed electrician. Toro’s manual says to consult a qualified electrician and local codes before installing any electrical product.
How far should the transformer be from a pool?
Follow your manual. Toro and Volt say at least 5 feet from a pool or spa and 10 feet from a fountain. Ring says not to mount its supply or lights within 10 feet of a pool, spa or fountain, and Kichler says 10 feet from any pool or pond. Use an electrician near water.
What is the difference between watts and volt-amps for LED lights?
Volt-amps count the lamp and its driver together. Toro’s manual says to multiply lamp watts by 1.5 to get volt-amps for LED loads, and to use that figure in place of watts when checking voltage drop. A 20-watt LED load is about 30 volt-amps. Check your lamp maker’s data for the exact figure.
Do I need a permit for low-voltage lighting?
Plug-in systems often do not, but local rules vary. New wiring and line-voltage work usually do. Toro’s manual says suitability of the combination is decided by local inspection authorities. Ask your building department which edition of the electrical code applies and what needs a permit.
Sources
- Toro / Unique Lighting, LED Transformer 12-15 Volt Low-Voltage Landscape and Fountain Lighting Power Supply, installation instructions, Part 373-1123 Rev A (2024; PDF read with pdftotext), retrieved .
- Ring, Smart Lighting Transformer manual (manufacturer PDF; read with pdftotext), retrieved .
- Volt Lighting, LOWTR-100W-SS Low Voltage Landscape Transformer, installation instructions (manufacturer PDF; read with pdftotext), retrieved .
- Kichler Lighting, Prepping for Installation: Calculating Your Project Load Size (professional guide), retrieved .
- Iowa State University Extension and Outreach, Yard and Garden, Landscaping with Light (Sherry Rindels, May 25, 1994), retrieved .
- City of Geneva, Illinois, Building Division, Pergola Permit Information (revised 4/20/20; list of adopted codes; PDF read with pdftotext), retrieved .
Expert review
Written by the HyreYard Research Desk. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Wire, tap, voltage-drop and GFCI statements are printed as each named manufacturer manual or guide states them, for that product only. The voltage-drop example scaling is HyreYard arithmetic and is labeled.
The NEC was not read: Article 411 is named only by its subject, and no edition, section or table is cited. Awaiting a licensed electrician reviewer; none is named.
Suggest a correction. We fix errors and say what changed.