LDPI, Inc. LDPI, Inc. http://www.ldpi-inc.com Sun, 19 Nov 2017 15:11:20 -0600 Sun, 19 Nov 2017 15:11:20 -0600 en Frequently Asked Questions About Lighting http://www.ldpi-inc.com/Frequently-Asked-Questions-About-Lighting Sun, 22 Dec 2002 00:00:00 -0600 <p><strong>Why is a lamp's CRI or CCT important?</strong><br />The Color Rendering Index (CRI) is the reason that the shirt and pants you thought matched so well at home seem to clash in the restroom at work. The closer the CRI of a lamp is to 100, the more "true" it renders colors in the environment. For individuals, such as graphic artists who perform tasks that require color precision or discrimination, lamps with a high CRI are recommended. Full-spectrum lamps are available that offer a CRI of over 90.<br /><br />Warm and inviting are some of the words used to describe environments that contain lamps with a Correlated Color Temperature (CCT) of 3000K. Coffee shops, restaurants, and hotel lobbies are a few applications in which cozy lighting environments are desirable. Hospitals, cafeterias, classrooms, and conference rooms are areas where an image of neatness is important. Lamps that appear cool - measuring a CCT of 4100K - are most appropriate for these types of applications. By comparison, daylight measures 5000K, and neutral lamps have a CCT of 3500K.<br /><br /><strong>What are the differentiating characteristics of incandescent, fluorescent, and high-intensity discharge (HID) lamps?</strong><br /><em>Incandescent lamps:</em></p> <ul> <li>Appear "warm" in color and have excellent color rendering.</li> <li>Are the least efficient of general lamp types due to the amount of energy consumed heating the filament in order for the lamp to turn incandescent.</li> <li>Have a short lamp life of between 500 and 3,000 hours.</li> <li>Are easy to install because no ballast is required.</li> </ul> <p><br /><em>Fluorescent lamps:</em></p> <ul> <li>Are available in a complete range of color combinations.</li> <li>Produce low heat.</li> <li>Require a more extensive installation because ballasts are a necessary part of the fixture.</li> <li>Have an extremely long life of up to 24,000 hours.</li> <li>Due to smaller sizes and screw base features, fluorescents can replace incandescent lamps.</li> </ul> <p><br /><em>High-intensity discharge (HID) lamps:</em></p> <ul> <li>Are ideal for large stores, warehouses, auditoriums, outdoor parking areas, and applications where efficiency is a priority.</li> <li>Have a warm-up period, which results in slower start-up.</li> <li>Deliver a large amount of light over a wide area.</li> <li>Have a long life of between 5,000 and 24,000 hours.</li> <li>Require ballasts.</li> </ul> <p><br /><strong>How do T12, T10, T8, and T5 fluorescent lamps differ?</strong><br />These four lamps vary in diameter (ranging from 1.5 inches to 0.625 or five-eighths of an inch in diameter). Efficacy is another area that distinguishes one from another. T8 lamps offer a 5-percent increase in efficacy over 34-watt T12 lamps, and have become the most popular choice for new installations.<br /><br /><em>Choosing Light Sources for General Lighting</em>, published in 1998 by the Illuminating Engineering Society of North America (IESNA), New York City, states that although they are available in lengths similar to the T12, T8s require a different ballast. For retrofit, the T10 is compatible with T12 ballasts. The T10 also uses a higher-efficiency phosphor and has a greater efficacy than the T12.<br /><br />T5s are straight tube lamps with a high efficacy. Due to their unique sizes (available only in "metric" lengths) and special ballast requirements, the T5 is a favorable choice for retrofits for VHO fixtures.<br /><br /></p> <h3>GLOSSARY OF LIGHTING TERMS</h3> <blockquote> <p><strong>Color rendering index (CRI)</strong> - a method for describing the effect of a light source on the color appearance of objects being illuminated, with a CRI of 100 representing the reference condition (and the maximum CRI possible). In general, a lower CRI indicates that some colors may appear unnatural when illuminated by a lamp.<br /><br /><strong>Color temperature</strong> - see correlated color temperature.<br /><br /><strong>Constant-wattage autotransformer (CWA)</strong> - the most common type of ballast used for HID lamps, it maintains a constant power (wattage) supply to the lamp when system input voltage fluctuates.<br /><br /><strong>Correlated color temperature (CCT)</strong> - a description of the color appearance of a light source in terms of warmth or coolness, as measured on the Kelvin scale (K). As the temperature rises, the color appearance shifts from yellow to blue. Thus, lamps with a low CCT (3000K or less) have a yellow-white color appearance and are described as "warm"; lamps with a high CCT (4000K and higher) have a blue-white color appearance and are described as "cool".<br /><br /><strong>Ballast factor (BF)</strong> - the ratio of light output of a lamp operated by a given ballast to the light output of the same lamp when operated by a reference ballast. Lamps operated by a ballast with BF of 0.90 will provide 90 percent of their rated light output (lumens). BFs between 0.85 and 1.0 are the most common.<br /><br /><strong>Disability glare</strong> - light that is relatively bright compared to the background, making vision measurably worse. The inability to see clearly as a result of the brightness of headlights from an oncoming car at night is an example.<br /><br /><strong>Discomfort glare</strong> - the type of glare that is uncomfortable and distracting, yet less obvious than disability glare. A bright light source in an individual's peripheral vision is an example.<br /><br /><strong>Efficacy</strong> - the ratio of light output (lumens) to input power (watts) expressed in lumens per watt (LPW).<br /><br /><strong>High pressure sodium (HPS)</strong> - a high-intensity discharge lamp type that uses sodium under high pressure as the primary light-producing element.<br /><br /><strong>Illuminance</strong> - The amount of light that reaches a surface. Illuminance is measured in footcandles (lumens/square foot) or lux (lumens/square meter). One footcandle equals 10.76 lux, although for convenience the IESNA uses 10 lux as the equivalent.<br /><br /><strong>Instant-start</strong> - a method of starting fluorescent lamps. The voltage, which is applied across the electrodes to strike the electric arc, is up to twice as high as it is with other starting methods. The higher voltage is necessary because the electrodes are not heated prior to starting.<br /><br /><strong>Lamp life</strong> - the median life span of a very large number of lamps. Half of the lamps in a sample are likely to fail before the rated lamp life, and half are likely to survive beyond the rated lamp life.<br /><br /><strong>Lamp lumen depreciation (LLD)</strong> - the reduction in lamp light output that progressively occurs during lamp life.<br /><br /><strong>Lumen (lm)</strong> - a unit of measurement of the rate at which a lamp produces light. A lamp's light output rating expresses the total amount of light emitted in all directions per unit time. Ratings of initial light output provided by manufacturers express the total light output after 100 hours of operation.<br /><br /><strong>Luminance</strong> - the photometric quantity most closely associated with the perception of brightness, measured in units of luminous intensity (candelas) per unit area (feet squared or meters squared).<br /><br /><strong>Luminaire efficiency</strong> - the ratio of the light emitted by luminaire to the light emitted by the lamp or lamps within it. Components of a luminaire, such as reflectors and diffusers, absorb some of the light from the lamps(s). A highly efficient luminaire emits most of the light that the lamp(s) emits.<br /><br /><strong>Mercury vapor (MV)</strong> - a high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements.<br /><br /><strong>Metal halide (MH)</strong> - a high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements.<br /><br /><strong>Open-circuit voltage</strong> - the voltage applied across the output terminals of a ballast when no load is connected. This is the voltage applied across a lamp circuit to start a lamp. After starting, the voltage rapidly decreases and stabilizes at the operating voltage.<br /><br /><strong>Preheat</strong> - a method of starting fluorescent lamps in which the electrodes are heated before a switch opens to allow a starting voltage to be applied across the lamp. With preheat starting, the lamp flashes on and off for a few seconds before staying lit.<br /><br /><strong>Power factor</strong> - a measure of how effectively a ballast converts current and voltage into usable power to operate the lamps. A power factor of 0.9 or greater indicates a high power-factor ballast.<br /><br /><strong>Prismatic lens</strong> - an optical component of a luminaire that is used to distribute the emitted light. It is usually a sheet of plastic with a pattern of pyramid-shaped refracting prisms on one side. Most ceiling mounted luminaries in commercial buildings use prismatic lenses.<br /><br /><strong>Rapid-start</strong> - a method of starting fluorescent lamps in which the ballast supplies voltage to heat the lamp electrodes for one to two seconds prior to starting and, in most cases, during lamp operation. A rapid-start system starts smoothly, without flashing.<br /><br /><strong>Reflected glare</strong> - often called veiling reflections, glare that results from light shining off polished or glossy surfaces.<br /><br /><strong>Restrike time</strong> - the time required for a lamp to restrike, or start, after the lamp is extinguished. Normally, HID lamps need to cool before they can be restarted.<br /><br /><strong>Visual comfort probability (VCP)</strong> - a system for estimating discomfort glare that predicts the percentage of people who are likely to find the lighting comfortable, against the percentage that find it uncomfortable.</p> </blockquote> http://www.ldpi-inc.com/Frequently-Asked-Questions-About-Lighting NEMA Plug and Receptable Configurations http://www.ldpi-inc.com/NEMA-Plug-and-Receptable-Configurations Mon, 03 Jun 2002 00:00:00 -0500 <p><span style="font-family: Arial,Helvetica,sans-serif;"><span class="style8">Configurations for:</span></span></p> <p>&bull; <span style="font-family: Arial,Helvetica,sans-serif;"><span class="style8">Straight blade plugs and receptacles</span></span><br />&bull; <span style="font-family: Arial,Helvetica,sans-serif;"><span class="style8">Locking plugs and receptacles</span></span><br />&bull; <span style="font-family: Arial,Helvetica,sans-serif;"><span class="style8">20A / 30A - 3, 4, and 5 wire locking plugs and receptacles</span></span></p> <ul> </ul> http://www.ldpi-inc.com/NEMA-Plug-and-Receptable-Configurations Area Classifications - Flammable Gases, Vapors and Liquids http://www.ldpi-inc.com/Area-Classifications-Flammable-Gases-Vapors-and-Liquids Thu, 03 Jan 2002 00:00:00 -0600 <h4>CEC/NEC (North American) Area Classifications</h4> <p><strong>Flammable gases, vapors or liquids</strong></p> <p><strong>IMPORTANT NOTICE REGARDING THESE DOCUMENTS</strong></p> <p>LDPI disclaims liability for any personal injury, property or other damages of any nature whatsoever, whether special, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this document. LDPI also makes no guaranty or warranty as to the accuracy or completeness of any information published herein.</p> <p>In issuing and making this document available, LDPI is not undertaking to render professional or other services for or on behalf of any person or entity, nor undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstance.</p> <p>This document is intended as a simplified guide through hazardous and extreme conditions as found in many industrial applications. For actual installations, use the NEC/CEC code book and IEC/CECELEC approvals and wiring codes as final authority on any installation. All design should be performed by licensed professional engineers and installation should be performed by competent licensed electrical contractors.</p> <p>Class I</p> <p>Class I (Gas and Vapors) Hazardous Substances</p> <p>Class II</p> <p>Class II (Explosive Dusts) Hazardous Substances</p> <p>Class III</p> <p>Euro: IEC/CENELEC Area Classifications</p> http://www.ldpi-inc.com/Area-Classifications-Flammable-Gases-Vapors-and-Liquids Group Relamping & Maintenence vs. Spot Relamping http://www.ldpi-inc.com/Group-Relamping-Maintenence-vs-Spot-Relamping Sat, 22 Dec 2001 00:00:00 -0600 <p>Group relamping is one of the most important aspects of lighting maintenance. Based on careful planning, scheduled group relamping involves calculating the average rated life and the average output of the lamps in your fixtures.<br /><br />While spot relamping (one-by-one, as lamps burn out) is an alternative approach, it can be up to five times more expensive than relamping on a regular basis and, it does not offer the efficient utilization of maintenance labor that is standard with group relamping.<br /><br />With group relamping, all the lamps in a given area are replaced at a scheduled time. This method is actually the most effective and least cost-intensive approach. This procedure often includes the repairing or replacement of defective parts in the fixtures such as sockets and ballasts. It also includes washing and cleaning the reflective surfaces and lenses.<br /><br />When performed during off-peak hours, group relamping creates less inconvenience and disruption. Your lighting maintenance is a budgeted, controlled and most importantly, predicted expense. And by taking advantage of large quantity lamp discounts, you can save on the unit price of the lamps. And, group relamping ensures that you get the most footcandles for your energy dollar and that your lighting costs always meet your lighting specifications.</p> <p></p> <h3 class="center"><strong>Typical Fluorescent Lamp Mortality</strong></h3> <p class="center"><em>Typical Life Expectancy or Mortality Curve for Fluorescent Lamps<br /></em><img src="../../../../%7Eldpiinc/images/graphics/lamp-mortality.gif" alt="Lamp Mortality Graph" align="middle" /></p> <p class="center"></p> <h3>GROUP RELAMP COST</h3> <blockquote> <p class="bodytext">Labor cost to group relamp 800 lamps (every 4 years or 2 times over the 8 years). Group replacement time of 5 minutes per lamp (significant gains in efficiency due to replacing all lamps in each fixture in an area at the same time). Utilizing in-house loaded labor rate of $14.00/hour. Labor cost over 8 years will total (includes 4% inflation):</p> <h5>$1,985.00</h5> <p><br />Labor cost for spot replacements after a group relamp 80 lamps over 8 years at the 20 minutes per lamp will cost (includes 4% inflation):</p> <h5>$420.00</h5> <p><br />Lamp cost to group relamp (2 times) and spot replacements over 8 years 1680 lamps. Total cost (includes 4% inflation):</p> <h5>$2,255.00</h5> <p><br />Supervision, ordering, inventory, etc. approximately 5% of total labor and material cost (again, efficiencies obtained and lower day-to-day activities and inventories):</p> <h5>$230.00</h5> <p><br /><strong>TOTAL COST OVER 8 YEARS</strong></p> <h5>$4,890.00 (or $610.00/year average)</h5> <p></p> </blockquote> <h3>SPOT RELAMP COST</h3> <blockquote> <p class="bodytext">Labor cost to individually spot replace 800 lamps (over 8-year period). Replacement time of 20 minutes per lamp (includes time to get ladder and lamp materials from stock room). Utilizing an in-house loaded labor rate of $14.00/hr. Labor cost over 8 years will total (includes 4% inflation):</p> <h5>$4,300.00</h5> <p><br />Lamp cost to individually spot replace 800 lamps at $1.30 each. Total cost over the 8 year period (includes 4% inflation):</p> <h5>$1,195.00</h5> <p><br />Supervision, ordering materials, inventory cost, etc. approximately 10% of labor and material cost (stated above):</p> <h5>$550.00</h5> <p><br /><strong>TOTAL COST OVER 8 YEARS</strong></p> <h5>$6,045.00 (or $755.00/year average)</h5> </blockquote> <p></p> <h3>Summary</h3> <p>Group Replacement Cost (Over 8-Year Period) $4,890.00<br /> Spot Replacement Cost (Over 8-Year Period) $6,045.00<br /> <strong>NET SAVINGS (Over 8-Year Period, 20%) $1,155.00</strong></p> <p><sub>For analysis purposes. The previous comparison is based on a typical medium size retail location as follows;<br />Typical location: Number of Lamps - 800 ea. F40/CW/SS<br />Annual operating hours: 5040 hours (14 hr/day x 360 days/year - includes 1 hour before and 1 hour after open.</sub></p> http://www.ldpi-inc.com/Group-Relamping-Maintenence-vs-Spot-Relamping Fundamentals of Paint Spray Booth Lighting http://www.ldpi-inc.com/Fundamentals-of-Paint-Spray-Booth-Lighting Sat, 01 May 1999 00:00:00 -0500 <p>Written by Mike Singer, as seen in <strong>Metal Finishing</strong>, May 1999</p> <p>Selecting the proper lighting For spray booth applications is critical to help optimize quality of workmanship and productivity. The type and size of the booth also has a direct bearing on the number, type, and size of the light fixtures needed to achieve proper lighting conditions. In general, the larger the size of the booth, the increased number of fixtures needed.<br /><br />The most common type of lighting used in paint spray booths are panel mounted fluorescent lighting fixtures. The fixtures are actually mounted and recessed in the booth panels. These fixtures are commonly Class I, Division 2 or Class I, Division 1 rated fixtures and are third party listed for hazardous locations. Class I, Division 2 locations are those where volatile flammable liquids or gases are handled, processed, or used. Normally, they will be confined within closed systems from which they can escape only in the case of rupture or deterioration of the systems.<br /><br />Panel mounted design provides a simple and efficient means of installation. These fixtures are typically constructed of either 18 or 20 gauge steel construction. Coupled with a white baked enamel finish, a durable and highly reflective fixture finish is created. A clear, tempered safety glass lens is sealed and gasketed to ensure a durable, long lasting seal against vapor, dust, and moisture. Commonly used fixtures of this type used in paint spray booths are 4 lamp, 4-foot fixtures with 32, 40, or 60-watt HO lamps, with 40-watt lamps being the most commonly used. The fixtures will normally have an inside, rear, or dual inside/rear access hinged door panel for the purpose of servicing the lamps and ballasts.</p> <p><br />In fixtures with an inside access, an interlock switch is provided and is to be wired in such a way as to disable paint spray equipment when the inside access panel is opened. This enables the fixture to be mounted in spray booth panels without the previously required second lens. In instances where a non-hazardous rated fixture is used, these must be mounted behind a sealed stationary mounted lens. These fixtures can only be serviced from the outside of the booth.<br /><br />Hazardous rated fixtures must, by code, be used in areas that extend from the edges of any opening of the booth in accordance with the following:<br /><br /></p> <ul> <li>If the exhaust ventilation system is interlocked with the spray application equipment, then the Division 2 location shall extend 5 feet horizontally and 3 feet vertically from the open face or open front of the booth.</li> <li>If the exhaust ventilation system is not interlocked with the spray application equipment, then the Division 2 location shall extend 10 feet horizontally and 3 feet vertically from the open face or open front of the booth. The term interlocked means that the spray application equipment cannot be operated unless the exhaust ventilation system is operating and functioning properly and spray application is automatically stopped if the exhaust ventilation system fails.</li> </ul> <p><br />If fluorescent light fixtures are actually mounted inside a paint spray booth and are not recessed panel mounted, then Class I, Division 1 explosion proof fixtures must be used. These fixtures are typically available with 2, 3, or 4 lamps in 2 foot or 4 foot length fixtures. A Class I, Division 1 location is defined as where hazardous atmosphere may be present during normal operations. It may be present continuously, intermittently, periodically, or during normal repair or maintenance operations, or those areas where a breakdown in processing equipment releases hazardous vapors with the simultaneous failure of electrical equipment.<br /><br />When actually selecting light fixtures for a paint spray booth, it is important to think about what you want to achieve and to get an even distribution of lighting in the booth. There are many factors that can influence lighting levels in a spray booth application. In order to help select the right fixtures, the following information is important to know:<br /><br /><strong>Booth Information</strong></p> <ul> <li>Is the application retrofit or new?</li> <li>What are the inside dimensions of the booth? (To include width, length, and depth.)</li> <li>What is the specific booth design?</li> <li>If a retrofit situation, what are the type and number of existing lights in the booth?</li> <li>For servicing, do you want the lights to be inside access, outside access, or both?</li> <li>Does the existing booth have a hipped ceiling? If yes, what is the hip size and degree? Are there lights in the hip, and is it possible to add lights to the hip?</li> <li>Does an existing booth have corner chambers, and what are the sizes?</li> <li>What construction is the booth floor?</li> <li>What materials are used for booth construction in the floor, walls, and ceiling, and what are the specific colors?</li> <li>Are there man-doors in the booth walls? If so, where?</li> <li>Are there any windows or translucent panels? If so, where?</li> <li>Are the filters located in the floor, ceiling, or booth walls?</li> </ul> <p><br /><strong>Objects</strong></p> <ul> <li>What types of products are normally painted?</li> <li>What are the shapes of the products (square, round, rectangular, etc.)?</li> <li>What is the largest object in terms of width, height, and depth?</li> <li>What is the smallest object in terms of width, height, and depth?</li> <li>What colors are primarily painted?</li> </ul> <p><br />With this information, light fixture manufacturers can use computer programs to help determine the recommended number and placement of the fixtures.; As a rule of thumb, 100 foot-candles at a 3-foot height has been a general industry standard. If a different foot-candle level is desired to be maintained at a different height, this should be communicated to your lighting supplier. Light intensity measured on a plane, at a specific location, is referred to as illuminance. Illuminance is measured in foot-candles, which essentially are lumens per square foot. Other factors such as reflectance of surrounding surfaces, fixture efficiency, and lamp lumen output can influence the type and quantity of needed light fixtures. As mentioned earlier, the size of a paint booth also can influence the size of the fixtures. In larger booths, such as truck paint spray booths, 4 lamp, 8-foot length fixtures featuring 95 or 110-watt HO lamps are sometimes desired. The type of a booth can also influence the choice of fixtures. Slim light fixtures that feature a compact design, which are just 2 1/4-in. fixture depth, allow for mounting in an insulated panel.<br /><br />The ability to see colors properly is another aspect of lighting quality. Light sources vary widely in their ability to accurately reflect true colors of objects. The color rendering index (CRI) scale is used to compare the effect of a light source on the color appearance of its surroundings. A scale of 0 to 100 defines CRI. The higher the color rendering index, the less color shift or distortion that occurs. As an example, a standard cool white T12 (1.5' diameter) fluorescent lamp with a Kelvin temperature of approximately 4100oK has a CRI of 62, which is considered low. Where quality or color matching is important, a higher CRI rated lamp will normally be needed. As a general rule of thumb, the higher the CRI, the lower the efficiency of the lamp. It is important that a balanced approach be used when considering CRI, lamp lumen output, and efficiency of the lamp.<br /><br />For many years, the lighting standard has been F40T12 fluorescent lamps. These are 40 watt, 1.5' diameter lamps. Through technological advances, lamps have been developed that consume less energy, produce better quality and higher levels of light, such as T8 (1' diameter) lamps. The T5 (5/8' diameter) lamps, which are starting to be introduced to the U.S. market, show even more promising results concerning maintained lumen output over the life of the lamp, energy savings, and they operate more efficiently at higher ambient temperatures than T8 or T12 lamps.<br /><br />Once the light fixtures have been installed in the spray booth, care must be taken to prevent dirt accumulation and paint over-spray buildup on the fixture lenses. If not removed on a continual basis, this will degrade the overall lighting quality in a booth. A simple, effective light fixture lens covering is cling-on plastic film. This is a 3 mil plastic with a custom acrylic adhesive in 12" and 18" widths. It is easy and quick to install and remove. A total re-lamping program should also be considered as lamps reach the end of their life.<br /><br />In conclusion, lighting selection in a paint spray booth should not be taken for granted. Different applications can require different light properties. To correctly match the proper lamp, ballast, and fixture combination, you should consult and work closely with your lighting supplier before making your lighting selection. One such manufacturer of fluorescent lighting for paint spray booths and hazardous industrial locations is LDPI Lighting, 4404 Anderson Drive, Eau Claire, Wisconsin 54703. They specialize in this area and are an acknowledged industry leader in providing lighting solutions for paint booths and hazardous industrial locations. Their toll free telephone number is 800-854-0021, and their fax number is 715-839-8145. Their website is <a href="http://www.ldpi-inc.com/">www.ldpi-inc.com</a> and email address is <a href="mailto:sales@ldpi-inc.com">sales@ldpi-inc.com.</a></p> http://www.ldpi-inc.com/Fundamentals-of-Paint-Spray-Booth-Lighting