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#50762 04/11/05 12:14 PM
Joined: Feb 2003
Posts: 687
For line voltage outdoor lighting I wanted to know the best methods to make it last using pipe. I'm thinking of the smaller lights and spot light that have the 1/2 pipe thread on the bottom.

I'm fine with RMC but it costs $$ now.

ENT is still cheap so it is my ideal raceway.

I seen many set ups for boxes but most seem to hold water and or mud.
Part of the problem is the customer does not want to see the box or much of the spot light base.

So I see all types of boxes mounted in or just above the ground.

How do you make it drain? Have an empty pipe strait in the ground? Drill a drain hole?

What do you use for splices? What are you useing to water proof the splices?


Joined: May 2003
Posts: 2,876
e57 Offline
I'm not allowed to use ENT (smurf) around here. And I'm not a big fan of UF, which I also can't use here. But indivual runs to each light from small round christy boxes near a plant, or off the pathes to cover a few lights each works well when nobody wants a box under each one.

Mark Heller
"Well - I oughta....." -Jackie Gleason
Joined: Oct 2004
Posts: 132
I recently did a low voltage install using pipe. RGC is a little overkill, IMHO for most places, plus it corrodes. The cadillac of raceways would be PVC coated RGC, but I'm sure you know what that costs (3x RGC).

I used Schedule 80 PVC and PVC lighting standards to hold all the fixtures. Here's one I used, many companies make them:

I got the cap in brass and had them acid wash it so it's a dull green (like copper) color, customer loves it, as the fixtures are copper acid wash, so it all blends in with the landscape. I got all my fixtures from Focus Lighting, they seem to be the only ones that will do the acid washing. Leave it a few inches above grade and backfill with river rock or similar around it to keep plants away from lights. You can run 3-4 3/4" PVC conduits up into the bottom of the mounting post, and make splices there. I used the King waterproof wirenuts to avoid future problems. Although my install was LV, I used #10 THWN throughout, and put coupler on the ends of the PVC to reduce cutting from the sharp edge.

All the installations I've seen with aluminum WP boxes get taken over by mother nature in a few years. Anything at or above grade should be plastic, stainless, copper, brass or bronze. Everything else just rots away.

Making an install of lighting last takes a bit more money, but if you can explain to the customer that it keeps you from having to install a whole new system in 5 years, that will be worth it.

Joined: Nov 2002
Posts: 267
I saw the site you left there. We sell very similar products at my place made by arlington. They're 19" tall and 37" tall ones, black and green. Being in the Northeast the 37" ones comes in handy if you need to beat the snow line. The lights we sell for this application are the hadco brand, 75 watt quatz. Nice set up.


Joined: Oct 2004
Posts: 132
I've used the arlington before, seem to work pretty good. I've been doing all my LV installs with the mounting posts and PVC for a while now, it is the only way to go, keeps gardeners from messing things up (they think it's high voltage stuff!) and it's easy to keep track of wiring and make changes in the future.

Hadco are good fixtures too, 120V halogen is rarely installed around here any more (southern cali), most people want 12v MR-16 (resi) or 13/26w cfl floods (comm), or the newer MH spots and stuff for palm trees and the like.

Joined: Jan 2005
Posts: 74
I just completed a large residential landscape project and I find that quazite boxes [fiber concrete w/ open bottoms] work the best, just make sure they are installed with drainage gravel underneath.

I pipe the trunk runs from end to end in pipe, type dictated by depth able to dig and AHJ.

I pipe from these boxes to a local point in garden beds or yard space then branch out in UF to each individual light. Rocket posts work the best, and with UF, relocating is easy. In a few spots on this job, I had to set the rokets in concrete due to depth issues. I just sleve the UF thru some pipe/flex and all is good.

For splicing, Ideal makes weatherproof wire nuts, 2 to a blister pack. Saves MANY headaches.

In tree lighting aplications, I use flex to a FS box, then flex to the required 8' above grade to a box or change over for cord.

oh yeah, as always I get the customers sprinkler contractor to do the digging, and if they don't have one I reccomend a couple of names to them.

Joined: Jan 2005
Posts: 5,445
Likes: 3
Cat Servant
Landscape lighting...the scene of much heartbreak!

Here is what works for me, as well as what hasn't worked very well.

Mounting the light is a real challenge; simply letting the conduit support it isn't enough. I will pound angle iron, or additional support pipes, a foot or two into the ground. Very often, I have the fixture mounted on a frame that is attached in turn to these supports. If I knew I was going to mount several lights, I might pre-fab a small concrete pad with the braces in it, and bury the pad.

Pipe is essential; I use PVC. UF cannot be re-pulled, or repaired without digging. I hate digging; I try to do it just once.
How deep? Code aside, you want the pipe to be at least a little more than one shovel blade deep, and below any lawn sprinkler piping. You want the gardner to miss hitting it when he goes to fix his lines.

Bell boxes are not satisfactory where they are in direct contact with the ground, or poured into concrete. They simply corrode away too fast. The same applies to buried extension cords?

Splices and connections are made in covered plastic (or Fiberglass) cylinders, open at the bottom. These are about 9" diameter, and a 18" long. You drill holes in their sides, or enter them from below; there is no connector or fitting used. Your wires are connected in the box with ordinary wire nits, then the entire nut is dipped in "Scotch-Kote." This gooey brown liquid is thinner than "Liquid Electric Tape," and costs about $1 per fluid ounce.

Landscape design can often lead to confusing layouts, so you should also pay extra attention to identifying circuits, breakers, and the location of controls. It is not unusual for the photocell to be located three buildings over! Likewise, receptacles should be identified as to any timers or photocells that may control them; several times the receptacle the gardner wanted to use was "on" only at night, as it was intended for the Christmas lighting!

Speaking of photocells: when you use them, especially when there is a contactor for controlling several circuits, it is worth your time to install a bypass switch in an accessible place, so the circuits can be easily tested.

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