long question re Shop lighting & electrical...

Re: long question re Shop lighting & electrical...

Greg Ladd

>Victor,

Regarding the electrical circuits; in my shop I have run 12/3 wire to all of the outlets and connected the red and black wires on individual breakers.

I then broke the Buss bar on the hot side of each receptacle which makes the top and bottom receptacles independent of each other when you connect the red wire on top and the black on the bottom,for example.

This tends to save on wire as you only pull one wire through the room. (Granted, it is 12/3 rather than 2 runs of 12/2 but it is cheaper and easier.)

It also gives you two circuits at each receptacle box which can be rather convenient at times.

Greg

Re: long question re Shop lighting & electrical...

sroxberg

>To meet code the breakers would have to be connected together so that you had to turn both on and off together, is that not true?

I wouldn't want someone to be zapped.

Not enough lighting

Dick Schmidt, Beaufort, NC

>Victor, My immediate thought is that your lighting may be a little weak given that you only have one window and assuming you will have an 8' sheetrocked ceiling painted white. Here is what I did. My shop is 32'x 40' with 10' ceilings and 13 large windows. As we age our eyes require more light on our work surfaces which average 3' above the floor. As I recall, experts say about 100 foot candles of light is about right - I planned for 125 fc to fall on my surfaces. I installed nine 4' strips in a row with each of 6 rows about 5 1/2' apart. I used 32W T8 daylight lamps. Even on a sunny day I will have the two center rows on. No one has ever said I have too much light but comment how well lit the shop is. Only at night will I have all 6 rows on. Another thing I did was to install several 65W floods in ceiling cans on their own switch so if I go out in the shop at night, not to work but to retrieve something, I do not have to turn the flourescents on. I am not a lighting engineer but I got started with an article in FWW a few years ago on shop lighting at the time I was planning my shop, followed by some research on the net. Various companies have calculators where you plug in the figures and out comes recommendations. Feel free to email me if you need more information. Regarding your electrical supply, if you have room in your panel box you should plan for 220V receptacles along with 110V. I am a single user shop, one machine at a time plus a DC and I have a total of 60 receptacles (12 are 220V) - you can never have too many. My entire shop, including AC, runs off a 100 amp circuit.

Re: long question re Shop lighting & electrical...

Tom MacGregor

>Another thing to look at is the fluorescent tubes themselves as the color of the light they produce makes a difference in how accurately you can see the colors of the objects they illuminate. It's measured two ways. The CRI or Color Rendering Index goes from 0 - full darkness, to 100 - full sunlight. A full spectrum bulb has a CRI of about 94 and sells at a premium. A "hot" as apposed to "cool" white bulb comes in about 85 CRI and is close enough to full spectrum that many people see no difference, and they're much cheaper. A temperature rating that indicates the color (NOT the temp. of the tube!) is usually printed on the tube. 3000K tubes are common, look for a 5000k or higher. Go by the K rating as most vendors haven't heard of the CRI.

see Woodcentral Articles

bill tindall

>I have an article in Articles section on lighting the shop that will provide some guidance. What you propose will provide adequate background lighting but not adequate task lighting.

not quite correct, more detail

bill tindall

>CRI and color temperatue are independent properites of a lamp. Color temperatue describes the hue of the lamp and it is related to the colors produced by hot objects(white hot, red, orange, etc like blacksmiths use to describe temperature). The "hotter"' the color temperature(bigger numbers) the whiter the light. 5000 or 6000K will look like sunlight and 3000K will look like an incandescent lamp. Experts disagree on whether people can see better at higher or lower color temperature, but people definitly have preferences.

As an aside, the K refers to degrees Kelvin, a temperature scale used by physisits. A 5000K lamp gives off the same color of light as an object at 5000 degrees K, which is very hot, "white" hot.

CRI describes how accurately colors look under the light compared either to sunlight or incandescent light, depending on the color temperaute of the lamp being compared. Cool lamps are compared to incandescent and hot lampls are compared to sun light. Unless one is doing accurate color matching it is not cost effective to buy the highest CRI lamps; something around 80 will do for shop work.

Raking light

Adam Cherubini, NJ

>Victor,

You might want to consider adding a provision for raking light. Raking, horizontal light, like the light from a window is something I've heard carvers talk about as a distinct advantage. I've used artificial lights to mimic this light in the past when flattening and smoothing walnut for example. I find this all but impossible with overhead lighting.

I used a high wattage flood light on a pole, but that was behind me. I'd like a more elegant solution that can be attached to the wall behind my bench (thus in front of me). I'd appreciate any ideas. I was thinking about a simple clamp-on incandescent.

Adam

Re: Raking light

David Barnett

>Raking lights can be simple (for carving or finishing), to elaborate (for document and surface analysis and photography using a gnomen, and so on).

For relief carving, which for me meant mostly liturgical lettering, I preferred a wide horizontal source. and one where the light glances across the surface yet does not directly strike the eye from the bulb source. My solution was a simple shade of copper sheet bent to a longish "J" form, with an 18" fluorescent tube and a clear 'showcase' incandescent, on separate switches. The curved part of the shade was held between two wood uprights, adjustable for height, and could swivel on its horizontal axis, as well. Outside of carving, I used a slanted work table to lay out lettering, gilding/stamping leather books, and so on, which controlled distortion and elongation, so the height adjustment and swiveling were a must. If I made one today (my first one's long gone), I'd use two Ott-Lite spiral compact fluorescents instead of the combination, one at each end, and a small dimmable halogen bulb in the center for the stark shadows and highlights (which is great for smooth planing, scraping and finishing). The inside of the shade should be white or white/silver if you wish to maintain a color temp in the 5500K range.

As an aside, I use lots of 5000K-5900K compact fluorescent bulbs, both because I can see so much better, but also because I need to accurately judge color on crafts other than woodworking. I reserve the Ott-lite "TrueColor" bulbs for gem carving, rendering, enameling, and use cheaper compact 'daylight' bulbs for most everything else. For raking light, because most of my work is small and I need cold light near my hands, I mostly use surgical fiber optic illuminators (EKE bulbs), with gooseneck and ring light guides (great for sharpening dovetail saws, btw).

Re: Raking light

mike recchione

>I read that the tradition for European carvers was to situate the bench in front of a window and to wear a white smock to reflect some of the light. This gave a strong raking source from the window side, with the reflected light providing some fill.

I set up my carving bench with an overhead flourescent pair around 4' or so above the benchtop, and an architect's lamp with a 60 watt incandescent bulb to create shadows, about 2 1/2' above the bench and to one side. (BTW - these things seem to have disappeared from the shelves everywhere. They were great - about $10, easy to position... Now they want to sell you something with a flourescent bulb in it for about 5 times the price, and the light isn't anywhere near as good for what I want it for.)

For relief carving, I like the light to hit the work at about 45 degrees so that I can see the depth and shadows. I haven't used raking light for "regular" woodworking, i.e. planing, etc. But I do use spots for layout and when I'm working at the lathe.

Good point but I don't know.

Greg Ladd

>I honestly don't know - maybe a licensed electrician or someone with a NEC code book handy could chime in. I can't imagine anyone sticking their fingers into a receptacle box without checking to make sure all of the circuits are dead but I know it happens.

Greg

The problem comes up when

Dan Donaldson

>The problem occurs when someone not familiar with the way it is wired shuts off the power. They may check one side of the plug, see that it is off, then get nailed by the other side. You can also run into problems if there are two circuits in the box on 12/3 and whoever wired the circuit ran the neutral through the plug. In this case, you check that everything is dead (which it is if the breaker is off), but as soon as you disconnect the plug, if there is anything plugged into the other circuit, the lifted neutral will become hot. BTDT. I have seen installations that were done this very way. The first time I worked on one, it got me, but after that I always looked to make sure that there was only one circuit going through the box.

Thanks for all the input.

Victor Parisian

>Thanks for the great input. Now if I can remember some of this when I'm out shopping Friday morning...

Special thanks for the raking lighting ideas as well. I really hadn't thought of this until now.

The cans with 65 watt lights for those quick trips to the shop is also a great idea I will need to incorporate.

No, I don't think I will split the upper and lower half of each outlet. But will leave adiquate explanation of the power scheme for whom ever buys this house in the future.

Regards to all,

Victor

Re: The problem comes up when

Greg Ladd

>Dan,

I certainly understand what the potential problems are.

It just amazes me that anyone would mess around with a receptacle without verifying that the breaker(s) are off. Tick testers and voltage meters are too cheap nowadays not to use one or the other.

And by the way, we should always verify that the testing device is working by checking it on a known hot circuit of adequate voltage immediate prior to usage.

Greg

An improtant update.....

Greg Ladd

>After a little research I confirmed what had been mentioned earlier. When splitting the circuits in a receptacle you must either use a 2 single pole breakers that are tied together with approved handles or you can use a single 2 pole breaker.

Just wanted to make sure no one did anything unsafe based on a suggestion I made.

Greg

Ditto.

Don Thompson - Cutler Ridge, Florida

>I used one of the online lighting calculators (can not remember the manufacturer- CRS), and the recommendation for my 14x16 shop was six, four-bulb, 48-inch, T8, 32-Watt fixtures. 24 bulbs total.

Re: The problem comes up when

Dan Donaldson

>In the case that I cited, the plug would be dead if you tested it, and the neutral would nail you when you took it out. You might not even realize tht there is another breaker to turn off. It is against code to break the neutral this way but.............