Monday, August 27, 2018

efficient workshop lighting 2

Lighting a work area in a pleasant, safe and efficient manner is about more than just changing light bulbs. I have changed some bulbs, added a few, tried new LED plug in florescent replacements and cleaned the rest. Big improvements! Low cost once you have modern electronic ballasts. Re-use the existing steel box which is often superior to what you'd buy new.

This is a view of my fabrication shop with ALL the lights on. [click any pic to enlarge] The lights in this room are almost NEVER All On. One of my principles of efficient lighting is to only use what I need. I have five lighting "zones" in this one room so I can have the amount and location of lighting that I need.

I switch my lights manually and I am pretty good at remembering to turn off when I leave the room. I tried motion sensing switches but they annoy me. None of these lights are network controllable, all are manual!

When I arrived here five years ago, there were four dual 40 watt T12 florescent lights on the ceiling switchable in two banks. The lights were along the sides of the room. The lamp fixtures were old and some of the lamps didn't work. Some of the fixtures had already been reused and were painted deep red.

Switching on the lights caused interference on my FM radio. See exploring efficient workshop lighting alternatives The title picture is approximately the same view as this article, five years ago (called P2 on the plan below).

Those four fixtures are in the same places (the green and the red banks) but they are now completely rebuilt with new electronic ballasts, new T8 32watt lamps and new lamp mounting posts.

Originally, there was no light in the center of the room. I added a circuit to the panel for an "island" in the center of the workshop ceiling with switchable lights (purple and yellow on the diagram) and a hanging power pendant. Both the lights are controlled with pull switches. Yellow is a High Output (HO) dual 50 watt T5 florescent (100 watt total) and purple are two LED bulbs, each 10watts (20 watt total).

The two LED bulbs provide the lowest level of illumination in the room at a cost of only 20 watts. Perfectly adequate basic illumination from two points near the center of the room.

Later, I added another pull chain controlled dual four foot 32watt T8 fixture over another bench in the bottom corner (blue). This is the fixture I used for the test below.

At move-in the ceiling was dirty white. I painted the ceiling with two coats of pure white latex in patches as I removed fixtures for rebuilding. Now, after four years, the ceiling is again turning a dirty white but not as bad as it was. I should probably repaint it.

Taking down and cleaning the now four year old T8 bulbs has made a huge difference in the room brightness.

The lamp showing the lettering was facing down, the other one is showing the "up" side, the side you normally don't see, the side facing the fixture. The accumulated dirt/dust cuts down the amount of light leaving half of the lamp.

Cleaning! So simple yet so effective! A lot of climbing the ladder in the last two days as I inspected and cleaned the eight fixtures that are now on the ceiling.

I also tried two new LED "instant replacements".

From Philips "InstantFit T8 LED, C$12 each at Home Depot. I bought one each of "daylight" (6000K) and cool white (5000K) so I could compare them. I had intended to buy two of the 6000K and that is what I will end up with since I have decided to return the 5000K after trying it out. The Philips 6000K seems subjectively brighter to me in my shop environment.

I bought Philips 32W replacement LED lamps a couple years ago and have been using them in the paint area. I have been pleased with them, judging them to be similar brightness to 32W fluorescent lamps but instantly full bright but twice the price. I believe two years ago, the Philips LED lamps were on sale at C$30.

I notice that now, the Philips lamps are glass. The earlier ones were encased in a plastic tube which would bend just slightly. The new Philips tubes also have lots of warning labels including about fire hazard. Perhaps the glass is needed for high temperatures? The lamps certainly do get warm, almost as warm as florescent.

The second type I tested was from Ecosmart, their 32W LED replacement (rated 20w each lamp), two in a pack for C$15 also at HD. Also glass. Far less warning info. Very bright!

Curiously, Ecosmart calls their bulbs "daylight" at 5000K. The naming of color temperature is a bit of a wild west I think, the degrees Kelvin should be a better guide or actually comparing in your own environment. Some time ago I did a piece on comparing conventional, compact florescent and LED bulbs and compared some of the visual effect of different color temperatures.

I installed the Philips and the Ecosmart bulbs in several different fixtures here but made measurements at bench height from the blue fixture

Comparison of lamp types
LampBrightness FCTemp (5 min)
Philips ALTO 32w florescent4635C
Ecosmart 20w LED5233C
Philips 17w LED36.526C

The Philips are not as bright as my typical T8 florescent. The Ecosmart is the brightest. The Ecosmart uses less power than the florescent, but more than the Philips LED.

Temperature was measured with an infrared temperature meter. Brightness was measured with a footcandle meter.

One detail of the comparison is that the LEDs came to full brightness immediately whereas the florescent takes several minutes to come to full brightness. Even longer at near zero temperatures. So the LED has a real advantage in my shop in winter.

Another detail is that general ceiling lighting is good for benchtop brighness but several of the machines, even with light fixtures directly over them, regardless of lamp type, need work lights ahead of the blade since the machine itself shields some of the overhead light. The band saw and the radial arm saw are examples that will need more attention for better safety.

Thank you for your interest,

George Plhak
Lions Head, Ontario, Canada

shop lighting reading list
a parabolic workshop light
led household bulbs
exploring efficient workshop lighting alternatives
work light led retrofit
testing fluorescent light fixtures - the test jig
testing fluorescent light fixtures - the test method (video)
testing fluorescent fixtures - 40 watt
efficient workshop lighting 2 (this article)

Tuesday, August 14, 2018

what's an oscilloscope?

I had a couple guys here installing a high tech propane house furnace. Renovations also going on. The house is chaos. I had my Tektronix 7854 and 7L5 in the living room on the cart. One guy asks what it is? I reply the first oscilloscope with a computer. What's an oscilloscope? he asks. It lets you see electricity I replied. He seemed happy with that. Age about 40. What's an oscilloscope?

Thanks for your interest.

George Plhak
Lions Head, Ontario, Canada