Low-key Security Lights

Introduction: Low-key Security Lights

I was motivated to do this project because I wanted gentle accent lighting around the front of my house. I also wanted motion sensing for some perception of security. It's hard to find fixtures which have both dusk-to-dawn (half bright) & motion sensing (full bright). Additionally, security fixtures tend to be made for more of a "prison yard" experience (bright, glaring, alarming, repelling) with PAR38 spot/floodlights or, more recently: integrated LEDs (which seem harsher, and are cooler color temperature -- interfering with circadian sleep rhythm & less friendly to the Dark Sky initiative).

The only fixture I found which met my needs was the Heath-Zenith HZ-5318. It has a "DualBrite" feature for always-on (50% brightness dusk-to-dawn) as well as motion sensing (full brightness). It's rated for wet locations (direct exposure to water) using PAR38 spot/floodlights. But, if mounted in a sheltered location, other bulbs can be used.

This project has two distinct activities:

1. Fixture

One thing that didn't work for me: the HZ-5318's lights & sensor are mounted together. (If I mounted the lights as high as they can go, the sensor wouldn't have much visibility to motion. If I mounted the sensor to have visibility, then the lights would be too visible & glaring. They'd also be more exposed to weather, requiring the use of PAR38 bulbs, which are brighter than I want.).

I separated the sensor so it could be mounted independent of the lights. This allowed the lights to be mounted as high as possible (out of view; protected from weather). The sensor was mounted high enough that it isn't seen by a 6-foot tall person unless standing 6' from the fixture. However, the sensor will see that person from the neck down at 8' away, and waist down from 18' away. It's not blind to those distances. It's just not as easily seen, less sensitive to tree limbs moving in the wind, etc.

Note: Like many security lights, the HZ-5318 is intended to be mounted onto a common round weatherproof junction box. Installing this box, and running proper wire to it is beyond the scope of this instructable. Consult a licensed electrician if necessary.

2. Light bulb

This fixture is intended to use PAR38 spot/floodlights. This isn't required unless the fixture is mounted in a location exposed to water. I didn't want to use PAR38 because they're brighter than the gentle light I wanted to create. The least-bright PAR38 I found was 55w-equiv with 1100 lumens.[1]

I settled upon a GE Relax R14 soft-white (2700k) 25w-equiv bulb which is rated for damp locations. It produces 250 lumens. That's almost perfect for the mild effect I want.

However, because the R14 is a much smaller diameter[2] than a PAR38, it feels more glaring. To improve this condition, I modified the bulb to have a larger diffusion layer in front of it.

UPDATE: I have another idea for the diffusion layer which I discuss in the last step (#10).

[Footnote 1] Lumens is a measure of all light emitting from a source (in all directions). This means that the lumens for reflected lights (PAR38, R14) aren't comparable to ordinary omnidirectional lights, which you're probably familiar with inside the home. The reflected light puts its lumens in one direction, which will appear brighter than an omidirectional bulb (radiating mostly into useless space). Also, reflecting light causes a loss. If you put an ordinary 1600 lumen (100w-equiv) omnidirectional bulb in a reflector (and could measure the resulting lumens, which is beyond the means of the average person), it would result in about half the lumens. Conversely, if you could remove the reflector from a reflected bulb, it would produce almost twice the lumens, but would appear less bright at the location you want the light to be.

Another way to think about this: Lux is a measure of light falling on a particular surface. An 1100-lumen PAR38 will have higher "lux per lumen" (than an unreflected 1600-lumen omnidirectional bulb), but a lower "lumen per watt" due to the loss of reflecting light. Lux is something the average person can measure. Unfortunately, lux isn't shown on product labeling.

Therefore, when comparing bulbs at the store, you have to make some mental adjustments based upon how their designs differ (flood vs spot; reflected vs omni). A bulb could have relatively low lumens, but appear very bright/harsh. (This is also a factor with the new trend in clear-glass omnidirectional bulbs which offer a direct view to the LED "filament." If you compared a frosted/opal bulb to a clear glass, each having the same lumens, the clear glass is going to appear harsher, less pleasant to look at, require more time for night vision to recover from, etc.).

[Footnote 2] Reflected bulbs use standard designations such as (R14, R20, BR30, PAR38). The number refers to the diameter of the bulb in units of 1/8". Therefore, a PAR38 bulb is 4-3/4" diameter. R14 is 1-3/4".

Supplies

Fixture

  • Heath-Zenith HZ-5318-BZ motion-sensing fixture (with DualBrite for always-on 50%-brightness too)
  • 18-gauge stranded electrical wire. (You need colors that match the wires being extended. Typically, white, red and black)
  • Wire nuts (large enough for three to four 18-gauge stranded wires twisted together)
  • 1/2" black iron pipe (used for plumbing & gas):
    • nipple (I used 3-1/2" long, you'll use a length appropriate for your installation)
    • 45-degree elbow
  • 1/2" EMT Locknuts
  • Rustoleum enamel paint; dark-bronze, satin finish. (Canned, not spray. If you need to touch-up after installation, you won't risk overspray onto your house. Enamel is hard to clean up, compared to latex. If you touch-up, be extremely careful not to spill it on driveways, walls, etc.).

Light bulb

  • GE Relax LED R14 25w-equiv (4w actual) 250 lumens, 2700k warm/soft white (#44997; Desc: LED4DR14E9SW-LT2; UPC: 0 43168 44997 7)
  • E26-socket extender
  • 1-quart plastic mixing cup: UnitedSolutions-Plastics.com "Measure-Right" (Lowes SKU: 40008; UPC: 0 51596 99002 2)
  • Printer paper: 20lb; 92 brightness
  • #4 x 3/8" long sheet-metal screws
  • #4 washers

Step 1: [MODIFY FIXTURE] Remove Sensor

The HZ-5318 fixture comes wired together, ready to install. However, I wanted to mount the lamps higher than the sensor, making the lamps less visible (less glaring and more protected from the elements, so I could have more options for bulbs than strictly wet-rated). To do this, you must cut the wires shown in the attached diagram.

The lamp wires will be short after cutting. Later, you'll solder additional length to make them easier to reconnect.

The wire colors may differ from mine. Take a photo of yours before cutting. Regardless of the colors, you will see wires connected exactly as shown in the diagram. Later, you'll reconnect them exactly the same way they were.

Step 2: [MODIFY FIXTURE] Choose a Weatherproof Electrical Box Cover (for Lampholders)

With the sensor removed: the HZ-5318's cover plate is only used to mount the lampholders. (You should seal the unused hole with a threaded plug sold at hardware stores.). You can orient this original cover to mount the lamps slightly higher or lower, depending on your needs.

Or, you can buy a generic 3-hole cover at the hardware store. It mounts the lamps in the middle. (It also comes with a plug for the unused hole.).

I used the generic cover because I wanted the lights to be as high as possible, but didn't have space to mount them as high as the original cover would.

Step 3: [MODIFY FIXTURE] Extend Sensor

Now you can decide how far to mount the sensor from the lamps. The weatherproof electrical box's holes are for 1/2" conduit fittings -- which use the same thread as 1/2" pipe for plumbing & gas.

I used:

  • Black iron pipe:
    • nipple, 3-1/2" long (1/2" thread)
    • elbow, 45-degree (1/2" thread)
  • EMT locknuts 1/2" (on each end of the pipe. I.e., against the box's exterior, and against the 45-degree elbow)
  • Rustoleum "dark bronze" satin enamel paint to prevent rust (canned, not spray, for easier touch-up after installation)

Whether you choose black or galvanized pipe depends on whether you intend to paint it. Galvanized doesn't need painting because it won't rust. (It can be painted, but requires special zinc-rich paint.). Black iron pipe will rust, and typically should be painted (unless you want a rusted appearance.). It doesn't have to be painted with enamel. Latex will stick to it.

Both nipple & elbow have tapered threads. You could tighten them together without using a locknut. But, adjusting the elbow's direction will depend entirely on the threads into the box. By using a locknut against the elbow, you can balance how far the nipple threads into both box & elbow. This could look better.

Note: Pipe thread is tapered; EMT conduit thread isn't. To use EMT locknuts on the pipe, you'll need to swage the threads: Put the pipe in a vice; thread the locknut onto the pipe by hand until it's tight; use channel-lock pliers to force the locknut 1/8-turn further; back it off; then 1/8 turn further again (back it off again; repeat). In small steps the threads will conform.
The locknuts should thread freely onto more than 3/4 of the threads. This will give you flexibility when threading the parts together, and adjusting the elbow's direction.
Important: Because the pipe & elbow will contain electrical wires, feel around the inside for burrs & sharp edges. Use a file or emery cloth to smooth.
Also, the further you mount the sensor from the box, the more you should consider using conduit (EMT or plastic). For the length I used, pipe is more cosmetic/decorative; an integral part of the fixture itself. (It wouldn't look good using conduit fittings for such a short distance.). At some length (1 foot?), it would start being more of a "run" to a different location. Conduit would start to look more normal, serve its intended purpose, and could even be required by local building code.

Step 4: [MODIFY FIXTURE] Extend the Cut Wires (for Easier Reconnection)

It will be easier to reconnect the lampholders' wires if they are lengthened 2-3". My sensor's white & red wires required an additional 6-8". (I didn't lengthen my sensor's black wire. It was already fairly long.).

1. Merge the wire ends. I stripped 1/2" insulation from the ends, and pushed those ends into each other, which causes the strands to mesh together. I like this method better than twisting the wires over each other because it's less prone to create sharp points that could poke through tape/heatshrink.

2. Solder the wires. After I soldered these "meshed" joints, I used small wire snippers to remove any sharp points after soldering. (You could also use a file.). It's important to do this because sharp points could poke through the tape/heatshrink.

Note: The topic of soldering is beyond the scope of this instructable. There are many resources online to learn how to solder. Or, pay a licensed electrician to do this for you.

3. Tape the solder joints. I wrapped a 2-3" length of electrical tape over the solder joints. This creates about 5 layers of tape all the way around. If there are any sharp points in the solder, 5 layers of tape will be hard to wear through. (If I didn't cover the tape with heatshrink, I would tape up & down the insulation for better coverage & adhesion.).

4. Heatshrink over the tape. I used heatshrink tubing over all the soldered joints. (I don't trust electrical tape by itself. It can lose its adhesion.). Heatshrink tubing holds the tape in place, and adds an additional layer of insulation. (I don't trust heatshrink by itself. Sharp edges can poke through it easier than tape. I like to use both together.).

Note: You should use 18-gauge stranded wire. Also, it's good practice to use the same color wire as the wire being extended. (If not, it's common to wrap the end of the wire in tape of the same color as the wire being extended. You can buy electrical tape that is red, white & black.).

Step 5: [MODIFY FIXTURE] Install Fixture

Reconnect the wires you cut in step #1, and connect the black & white wires to the source of electricity (as the fixture's instructions describe, observing all warnings.).

The fixture comes with "wire nuts" for the connections to the house wiring. You'll need two additional wire nuts to reconnect the wires you cut. These nuts can be the same size as the fixture comes with, or a little smaller. (Look inside the wire nut to assess size. Sometimes the outside of wire nuts can be large, but small internally. It's the internal size that matters. You'll twist the stranded wires together clockwise, then screw the nut clockwise onto that. The nut needs to be large enough to grab & tighten onto the exposed wire. See videos on YouTube showing how to use wire nuts.).

I wrapped the sensor's wires together with electrical tape as additional protection against abrasion inside the iron pipe. You can also tape the ends together to protect the exposed wire strands; help it push through easier.

Note: this instructable assumes the weatherproof electrical box already exists, and appropriate wire has been properly run to the box. Consult a licensed electrician if necessary.

Step 6: [MODIFY BULB] Drill Hole for External Diffusion Disk

The HZ-5318 fixture is "wet" rated (constant exposure to water) when used with suitable bulb (typically a PAR38 flood or spotlight). However, I mounted the fixture so high under the eaves (for less visibility & glare) that it's not exposed to water. This allows me to choose from other, less-intense bulbs (which are indoor or "damp" rated). PAR38 bulbs are much brighter than I want. The least-bright PAR38 I found was a 55w-equivalent which produces 1100 lumens.[1]

For my goal to have mild accent lighting, I found the GE R14 25w-equivalent (4w actual, "damp" rated), 250 lumens. It produces a perfect amount of light hitting the ground & side of house. However, being only 1-3/4" diameter, the R14 bulb feels more intense/glaring compared to a PAR38's 4-3/4" diameter.[2]

My solution was to install a diffusion layer in front of the R14 bulb. Since the bulb's face is plastic, it seemed simple & elegant to attach this layer directly to the bulb.

UPDATE: See the last step (#10) for an alternate diffusion layer which attaches to the front of the hood.

Drill hole

1. The face of the bulb has a small molding imperfection in the center. Press the sharp point of a protractor or scribe into that spot to make a dimple which will hold the drill-bit centered.

2. With a 1/16" drill bit, drill a hole in the face of the bulb. I held the bit between my thumb/fingers. With the bulb in my other hand, I twisted them against each other while pushing fairly hard. It takes about 20 twists.

Important: The LEDs are mounted 5/8" beneath the bulb's face. When the drill bit breaks through the face, don't let it travel too far inside. (This is why I drilled it by hand. If you use a power drill, it's harder to control that breakthrough moment.). After drilling the hole, you can (and should) verify the clearance by gently lowering the bit into the bulb. Don't push it around inside. Just softly probe how far it goes down before touching anything. (Of course, never do this while the bulb is powered on.).
To the extent your fixture is mounted without shelter, this modification won't be appropriate. See the last step (#10) for an alternate diffusion layer.

Cut the threads

3. Using a 3/8" long #4 sheet-metal screw, screw it into the hole to cut the threads (for easier attachment of the diffusion layer.). You should press fairly hard as you start turning, to help the threads start. It may become difficult to turn. You can turn 1/4 turn, then back it off; then another quarter turn further (back off again; etc.).

WARNING: Because the LEDs are 5/8" below the bulb's face, you shouldn't use a screw longer than 3/8". The thickness of washer + diffusion layer will limit the amount of screw protruding into the bulb to about 1/4". If you use a longer screw, it could make contact with the LED mounting surface, creating a short or shock hazard. (A 1/4"-long screw might work. But, if I tried that, I would use a larger-diameter #6 screw to get more thread "bite" into the bulb's plastic face. The head of a larger-diameter screw will be more visible from the front. That's why I chose #4.).
Important: Be sure to verify the clearance after creating the hole. Sometimes designs change. (Just lower the drill bit gently through the hole until it stops. It's simple to check that way.).

[Footnote 1] See the intro for an explanation of what "lumens" are, and how lumens aren't comparable between reflected & omnidirectional lights.

[Footnote 2] As mentioned in the intro, bulb designations like PAR38 & R14 refer to the diameter of the bulb in 1/8" increments. You can find bulbs between PAR38 and R14, such as R20, BR30. Simply divide the number by 8 to know it's diameter.

Step 7: [MODIFY BULB] Make Diffusion Layer (Cut Bottom Off Plastic Cup)

For the diffusion layer, I found an inexpensive 1-quart plastic paint cup at Lowe's (United Solutions, "Measure-Right," SKU: 40008). I cut the bottom off, poked a hole in the center, and screwed this to the face of the bulb. (Ace Hardware has a plastic cup which looks like it would work too. Flat, clear sheet acrylic or styrene would be nice. Use fine sandpaper on both sides to make it obscure/frosted. More thoughts in this direction are in the last step, #10).

This cup-bottom fits perfectly inside the HZ-5318's lamp hood (at the depth of the bulb's face). If you used flat plastic, it might be able to be 4" diameter. The way the cup-bottom's lip rolls backwards, and being 3-1/2" across that lip, it fits perfectly.).

I laid an X-Acto knife flat on the table, and rotated the cup to score all the way around (pressing lightly). After 1-2 rotations, I pressed a little harder. The deeper the score, the more it will hold the knife on track. After the score was deep enough (6-8 rotations), I held the cup horizontally in my lap with one hand, and plunged the knife through the score with the other hand; then drug the knife through the score (all the way around). The deeper the score, the straighter the knife will pull through it. (You don't have to worry too much about how perfect the cut is. The way it faces backwards behind the bulb, and the hood blocks visibility, the cut won't be seen much.).

WARNING: Do NOT put your hand inside the cup to try to push against the knife. You'll cut yourself. Grasp the top of the cup & go slow; let the score deepen on its own. The deeper it is, the harder you can push against the knife (as you rotate the cup, pushing down against the table too).

UPDATE: Bugs tend to beat themselves into oblivion flying into the light. The lip tends to retain the nightly carnage. It could be better to make the diffusion layer from flat plastic, or perhaps cut a "V" into the lip at one location (rotate that to the lowest position, so they fall out easier.). See the last step (#10) for more thoughts about using a flat sheet of plastic.

Step 8: [MODIFY BULB] Add Paper Shade

I felt the diffusion layer was still a little too glaring. I cut a 3-1/4" and 2" circle from ordinary printer paper (20lb; 92 brightness) to shade the light.

You may not need paper shade. Or, maybe just the 2" center shade. You might try colored paper too (like canary yellow).

I drew my circles using a protractor which poked a hole in the center. I enlarged that hole by threading the #4 screw into it. (I also poked a hole in the center of the plastic-cup bottom, and threaded the screw into it to make later assembly easier.).

Hint: You can replace the protector's pencil with a Xacto #1 (thinnest) knife to make perfect circles. But, since the paper can't be seen, I cut mine by hand. (If you want to use the protractor to cut circles, I know that the Stanley-brand protractor works. But, you have to bend open [just a little] the clamp which holds the pencil. I used a couple of needle-nose pliers to grab opposing ends of that circle, and pull them apart a tiny distance.).
Note: If using more than one layer of paper, stack the smaller diameters closer to the light. This will make the edges less noticeable when the light shines through.

UPDATE: I noticed that small gnats were getting between the layers of paper. It's better to tape all the way around the 2" circle.

Step 9: [MODIFY BULB] Assemble & Install Bulb

You should have already threaded a #4 (3/8" long) screw into the bulb's face (to cut the threads). The protractor used to draw any paper shade should have poked a hole in the paper center (you should have enlarged that hole by threading the #4 screw into it too). And, you should have used the same protractor's point to poke a hole in the center of the plastic cup-bottom (the diffusion layer) -- and enlarged that hole using the screw.

Now you can attach all these together. However, you won't be able to install the bulb when they're all together. You'll need to install the bulb first, then screw the diffusion diffusion/shade assembly onto the bulb.

Reminder: The fixture is designed for PAR38 spot/floodlamps which have a long neck. You'll need an E26-socket extender to install the R14 bulb into this fixture. These are very common, and sold at hardware stores.

Important: Be careful not to overtighten the #4 screw. You can make it very snug. But, I suspect it will be easy to strip the threads if you try to tighten it down very hard. (If you do strip threads, instead of buying a new bulb, you can use a #6 screw. Again, be mindful of the length of the screw, that it won't protrude too deep and risk making contact with anything energized inside.).

Step 10: [UPDATE: DIFFUSION LAYER] No Bulb Modification

After completing this project, I've been thinking about a different difussion layer made with flat clear plastic (sanded both sides for a frosted/obscure appearance). I have attached three images which shouldn't require explanation. Cutting a perfect circle in plastic sheet is a different topic.[1]

The reasons this alternate diffusion layer is better:

1. Dead-bug accumulation

The cup-bottom's lip retains more bugs than a flat surface would. (I believe cutting a "V" in the lip, and rotating that notch to the lowest position would help. But, making the diffusion layer out of flat plastic would probably be better.).

2. Unorthodox modification to bulb

If the diffusion layer were attached to the hood, more bulbs would be available to choose from. I.e., not all bulbs are suitable for this mod. For example: "vintage" (2000-2200k) bulbs would be usable. (Hint: If you use a clear-glass bulb, I strongly suggest using Rustoleum "Frosted Glass" spray paint. This reduces glare even behind a diffusion layer.). It would also be easier to replace bulbs (no customization required).

However, benefits to using my bulb-attached diffusion layer: 1) it's quick and easy (compared to cutting nice circles in flat plastic, drilling more holes). 2) You don't have to use lamp hoods. (It looks fine without them under my eaves, where it's not too visible. Note: If you didn't use the hoods, you should give more thought to the mounting location. The hoods are part of the fixture's "wet" rating.).

3. Less need for paper shade

The further the diffusion layer is from the bulb, the more diffuse it will be. There will be less reason to use paper shade between the bulb and diffusion layer.

[Footnote 1] The topic of cutting nice circles from flat-plastic sheet is more challenging than you'd assume. There are tools to do it. (Ex., C-2500P Heavy Duty Circle Cutter, made my NT. Sold by Lion Office Products. Or, Olfa's CMP-2 Heavy Duty Circle Cutter.).

What I'm thinking of doing is:

  1. Use a 5" hole-saw on 3/8" thick plywood. Use the inside part of the circle as the template for a router. The inside piece of wood will be about 4-3/4" in diameter. (Remember: the inner circle of wood is where the "waste cut" occurs, and is typically thrown away.).

    I don't know much about routers. I believe they can use bearings to space the cutting surface away from a template. If it were possible to use a 4" hole-saw and a router's bearing to route a 4-3/4" circle in the plastic, I would do that. I imagine the smaller hole-saw would be less expensive, easier to control. (Note: There's nothing special about 4-3/4". The HZ-5318 fixture is designed to be used with PAR38 bulbs which are that diameter. The hood is a little more than 5-1/4" inside diameter.).
  2. Use a "finish" router. These are smaller & less expensive than an ordinary (full-size) router.
  3. Use double-sided tape to affix the template to the surface of flat plastic. (From what I've read, plastic can be cut with a router if the motor speed is set low, and you move slowly.).

I don't know much about plastic. I would probably use 3/16" (0.19") thick acrylic (or styrene). I would use fine sandpaper (400- & 800-grit) on both sides of the circle to create an obscured/frosted appearance.

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