aluminum spikes....why?

Discussion in 'Landscape Lighting' started by Lawn Designers, Nov 1, 2007.

  1. Lawn Designers

    Lawn Designers LawnSite Member
    from NY
    Messages: 11

    I am very new in the lighting arena but I was wondering why do lighting companies use aluminum spikes? It makes no sense to me at all. After 1-2 yrs they are completely rotted and the entire fixture needs to be replaced from the service jobs I have went to look at. Why doesn't every company use a non-metal spike? The PVC spikes make the most sense. Do the copper, brass and bronze spikes rot as much as the aluminum?
  2. NightScenes

    NightScenes LawnSite Silver Member
    Male, from Kingsland, Texas
    Messages: 2,214

    Only the cheapest fixtures like Malibu use aluminum stakes. I don't know of any "professional" lighting people that would use these products but I'm sure that there are some trunk slammers out there using that "stuff".
  3. Pro-Scapes

    Pro-Scapes LawnSite Platinum Member
    Messages: 4,180

    bronze stakes seem to hold up real well. PVC as long as its not exposed to sunlight is good too.

    I would never consider installing a fixture with alluminum in the ground like that
  4. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Messages: 4,102

    I am not a fan of non-metallic ground stakes. I like to know that all my ground mounted fixtures are in fact grounded. This adds an extra layer of safety.... I submit the following for your perusal:

    "The rapid growth of 12 volt outdoor lighting using plastic stakes should make safety a great concern to consumers. Plastic ground stakes used to support 12 volt metal outdoor lighting fixtures are a devastating accident waiting to happen!

    My transformer campaign for fire prevention a few years back has been credited with forcing the industry to change transformer design to a safer design in use today. I am compelled to take the industry to task for the use of plastic stakes. Yes, they are cheaper also durable. The problem with using plastic is it’s insulating qualities. Placing a metal electrical fixture in a plastic stake isolates the fixture from the earth (electrical ground). In the event that a live current carrying wire touched the metal fixture the entire fixture would become a source for a severe electrical shock.

    Being deeply involved in the industry for almost a half century gives me the knowledge and experience to speak out. I'm concerned about the future of our industry. However, I am more concerned about the possibility of a single fatal accident caused by using a plastic stake.

    How could this happen you ask? After all we are only dealing with 12 volts and UL says that 15 volts or less is OK. The heart of any 12 Volt system is the transformer, the item that reduces 120 Volt household electricity to a safe 12 Volt. The transformer is an electrical device containing two coils of copper wire, one for the 120 Volt while the other is isolated for the 12 Volt.

    In the event of a lighting strike or power surge causing one of the 120 Volt wires(within the transformer) to touch one of the 12 volt wires the transformer could continue to provide 12 Volt for the fixtures. However from the 12 volt wires to ground (earth) the voltage would be a deadly 120 Volt.

    Should the installing mechanic accidentally remove a small section of insulation from the 12 Volt wire allowing the bare wire to touch the metal fixture support, instantly the fixture becomes electrified with 120 Volt to ground. The 12 Volt lamp will continue to burn even though the fixture surface is charged with deadly 120V to ground making it possible for the unsuspecting to receive a deadly shock.

    Because the accidentally skinned wire is touching the metal fixture stem the metal parts become dangerously charged with 120 Volts. Should a person not knowing the danger of this 120 Volt be kneeling on the wet ground ( knees touching the wet ground) use the 12 Volt fixture as an assist to "getting up" they would be subject to a full 120V AC, far greater than the deadly 100 MiliAmps, the minimum for possible electrocution.

    Had a metal spike been used the scenario would be entirely different, it would have been SAFE! When the skinned wires from the fixture were inserted into the metal spike and then placed in the ground (earth), as the electricity was applied to the fixture immediately a fuse, circuit breaker or the GFCI would have interrupted this dangerous 120 Volt.

    I invite you in public service, professionals that are installing 12V AC outdoor lighting, Wholesale/retail businesses that are selling 12V (low voltage) outdoor lighting. E-mail me to receive a CD of a real live demonstration which will show you the need for a 12V AC installations either existing or new to be grounded at each individual fixture, either by metal spike or some other approved method. We do not need one single person maimed or killed "because it is cheaper". "This is the “Shocking Truth”." Bill Locklin, Nightscaping.

    As for Aluminum stakes, it all depends on your soil conditions. I have some pathlights that were installed almost 10 years ago with aluminum stakes and they are as good as the day I installed them. In other areas, the Aluminum doesn't last more then a couple of years.

    Have a great day.
  5. pete scalia

    pete scalia LawnSite Senior Member
    Messages: 960

    This is a statement based more on competitive advantage then on safety and I will tell you why. Why does Nightscaping use plastic bayonet sockets when most of the majors use brass-lower cost? Are their sockets grounded when isolated in a plastic shell (No)? in reality Isn't there more of a chance for a socket short than the scenario Mr Locklin put's forth regarding the knees on ground and grabbing a fixture? I don't doubt his scenario but it is very very very remote. The socket however is a real threat as I have seen many a shorted bayonet socket in my day. Now what if 120 v were running through that socket due to a trans malfunction and someone went to change a bulb and came in contact with it?
  6. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    This is where James and I part company a little, that is, not on the issue of a grounded metal stake, but aluminum stakes in particular.

    The only aluminum stake I've ever seen hold up to irrigated clay soils is the original 6061 T6 aluminum alloy stake that FX used to use.

    If a Nightscaping ground-mounted I want to order doesn't already come with a brass stake, I order it w/o stake and add the brass one instead. All the copper pathlights come with brass stakes standard.

    The Nightscaping cast aluminum stakes just haven't held up for more than three years in my experience in the soils in my area.

  7. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    I'm not sure what specific type of plastic is being used currently in the Nightscaping bayonet sockets, but it's a heat resistant plastic and the big advantage is it doesn't corrode.

    I agree that the grounding issue is dealing with a remote possibility. But Bill has always erred on the side of safety, and that's alright with me.
  8. pete scalia

    pete scalia LawnSite Senior Member
    Messages: 960

    If he always erred on the side of safety then what about his plastic sockets? I've seen so many of them broken it's not funny. Brass doesn't corrode either. The contacts are brass so why not make the whole enchilada brass like others- cost?
  9. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    I don't know why. Why not give Nightscaping a call and ask?

    FX uses sturdy brass bayonet sockets. It's standard with the handful of their fixtures that I use from time with an AR-11 bayonet halogen lamp (CL-20, TC-20, VL-20, TS-20).

    I know it's no excuse, but a few guys custom order the Nightscaping pathlights with bi-pin sockets.

    I've only had about 6 of the older style plastic Nightscaping sockets break (white) and none of the current ones (black)...
  10. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Messages: 4,102

    It has been a few years now since NS used the old white SCB sockets, and yes there was a problem with them breaking over time, specifically in applications like the Deliter where the socket was inverted. Since then they have switched to a black nylon SCB socket which has held up just fine.

    That being said, I am not a fan of SCB lamps, and so I order my fixtures with either wedge base or bi-pin sockets instead. They are happy to do this and the 'upcharge' is so minimal that it is not even noticed.

    I also agree, the 'shock scenario' that Bill spells out in his piece "The Shocking Truth" has a very very remote possibility of ever ocurring, but... it is possible and I do love to sleep at night.

    As for the Aluminium stake thing... its all about the soils

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