22 Nov IS LOW VOLTAGE LED OUTDOOR LIGHTING SAFE ?
By Mike Gambino
A week after devastating wildfires in both Northern and Southern California that media reports state may have been started by faulty primary high voltage wiring from the Electricity company provider no less, I think it’s appropriate to have an article about 12 volt electrical lighting systems and its safety. I have installed 1,000’s of outdoor lighting systems for almost 30 years now, primarily 12 volt Garden lighting. First incandescent and halogen and then for the past 10 years or so LED 12 volt outdoor lighting. I can tell you with conviction that when quality products with the proper built in safety devices are installed by highly experienced team members that 12 volt outdoor lighting is very much inherently safe.
That being said over this 30 year career I have seen some absolutely scary and unsafe installs in the field done by part timers, do it yourselfers and even licensed electricians.
My intent is not to get technical with this article but some basic information is needed. Ohm’s law states that the electrical current flowing in a circuit is proportional to the voltage and inversely proportional to the resistance. Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change. Amperage is measured by dividing Watts by Volts = Amps. 300 watts divided by 12 volts is 25 amps. 300 watts divided by 120 volts is 2.5 amps. A simple definition of Amperage is the strength of an electric current. Amperage is ten times higher with low voltage power than high voltage power with the same wattage draw.
Bill Locklin the inventor of the original 12 volt garden lighting system in the mid 1950’s knew better than anyone how potentially dangerous 12 volts can be and in some cases even more dangerous than 120 volt main power. Because of low voltage lightings reputation for being a safe and effective system when properly installed, it is taken for granted by some and the basic safety precautions normally taken when working with voltage that can kill you are not always followed.
Locklin used to say, and this is a direct quote, “It is much easier to burn a house down with 12 volts of power than it is to burn a house down with 120 volts”. 12 volt lighting operates on 1/10th the amount of electricity then 120 volt lighting does. The voltage is safe and in most all cases will not cause damage or harm to humans or animals when they come in direct contact with it. Albeit a cut or break in skin coming into direct contact with 12 volts of power is not a pleasant feeling but it probably won’t cause any serious harm or death. However it is not the voltage that can sometimes cause damage to property and humans it is high amperage caused by short circuits. Short circuits can occur when exposed electrical wires touch and short circuits not shut down by proper fusing or circuit breakers will produce extreme heat and can result in melted wires, burns and fires.
The other hazard risk of low voltage lighting systems is a defect occurring where 120 volts is allowed to cross over to wiring and equipment and circuits that were designed for 12 volts. Here is an article edited of extraneous information for brevity with important info in bold that details what can happen when the perfect storm of improper installation, corner cutting and unsafe products all collide and the tragedy that can result . The original article can be found here https://www.washingtonpost.com/local/public-safety/officials-reviewing-faulty-wiring-on-mgm-handrail-where-child-was-electrocuted-according-to-early-investigation/2018/09/25/54c00a1c-c029-11e8-90c9-23f963eea204_story.html?noredirect=on&utm_term=.6f2c09e036f1
Faulty wiring cited in early investigation of 6-year-old’s electrocution at MGM National Harbor
The hotel tower at MGM National Harbor. (Bill O’Leary/Washington Post)
By Lynh Bui and
September 25 2018
Investigators looking into the electrocution of a 6-year-old girl who was critically injured at MGM National Harbor say a device that controls the flow of electricity to lights on a handrail she touched was improperly installed, according to a preliminary assessment obtained by The Washington Post.
That faulty installation, combined with other flaws in how wiring and the handrail were hooked up at the Maryland complex, enabled 120 volts of electricity to be jolted into the girl — 10 times the amount that should have been powering the handrail lighting, according to the early findings.
The failures, investigators said, stem from “major” code violations that should not have passed the permitting and inspection process.
The findings are part of an ongoing investigation by Prince George’s County officials into the June 26 incident that has left the child hospitalized for three months.
Two people familiar with the investigation said that on the night the child was electrocuted, she and her brother were swinging on a loose handrail at the Potomac Plaza, an outdoor patio area with a large fountain on the west side of the property.
The handrail was electrified because of the improper installation, and when the girl touched a second handrail nearby to swing between them, she was electrocuted, according to the early assessment and the two people, who spoke on the condition of anonymity to talk freely about the continuing investigation.
A mechanism known as an LED driver — designed to cut 120 volts to 12 volts for the lighting on the underside of the handrail — failed, according to the preliminary review. The lights were used to illuminate parts of the pavilion and a nearby staircase, according to investigators’ description.
On the night of the electrocution, when the girl received the shock, a security guard tried to pull her off the rail, fire officials said at the time. The security guard and another child suffered injuries that weren’t life-threatening, the officials said.
The girl went into cardiac arrest, and officers at the MGM casino revived her using CPR. She remains in critical condition, according to people familiar with the investigation. The investigation has focused on the wiring and devices that power lights on the undersides of the handrails that illuminate the pavilion area, the early review states.
According to the preliminary assessment, a series of “failures” in how the wiring and handrail were installed and how the permits were approved “led to the event” of the girl’s electrocution:
- An LED driver used to convert electricity into smaller units failed “as a result of major issues with installation and permitting approval.” Four drivers were grouped in a single box so close together it inhibited airflow and posed a risk of overheating, melting and failure that should “have never passed inspection.”
- “The “wrong type of electrical wiring was used to power the lights.” Rather than the wiring specified by the manufacturer of the LED lights, communications wiring that is used for items including voice, data and audio transfers was employed. That errant wiring was then buried directly into the ground when it should have been encased or protected.
- The insulation on the outside of the wiring wore away, exposing copper conductors that made contact with the handrail and sent electrical current to the LED driver, causing the mechanism controlling voltage to the railing to fail and allow 120 volts to flow.
- The handrail the girl touched was loose because it was buried at an improper depth.
This was a horrible tragedy. Since this incident happened, the Baker Administration directed multiple agencies to investigate how this happened and to establish a plan of action to correct issues discovered and ensure this never happens again.”
Investigators said their preliminary review indicated other electrical problems at the property, which sits along the banks of the Potomac River.
“Inspectors later found a LED Driver that provided electrical current to the lights for other pavilion hand railings in the trash can,” according to the review. “Inspectors later determined that the LED Driver, which was recovered from the trash can, powered the adjacent handrail lights and had previously been buried underground. This is a major electrical code violation and safety issue.”
The point of this article is not to scare but to enlighten and raise awareness of the potential hazards of working with electricity of any voltage. The push to sell electrical products to anyone whether qualified or not to install them is at an all time high. Products are available for purchase without qualification requirements and this can prove to be very dangerous and result in loss of property or death.
If you are having any electrical work performed at your home or on your property make sure you are working with an experienced licensed and insured professional who specializes in that type of work you are having done. The lives of you and loved ones may depend upon it.
This landscape lighting blog is published by Mike Gambino of Gambino landscape lighting inc. all rights reserved. Mike is a professional landscape lighting system designer/ builder and has been designing, installing and maintaining landscape lighting systems for more than 28 years. Mike resides in the Los Angeles area with his wife and 2 sons. To visit his website go to www.Gambinolighting.com . To inquire about hiring Mike please click here .
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