1.
What is the procedure for warranty issues regarding the lamp and ballasts?
All T5 and T5HO lamps are covered by a 2-year warranty by the manufacturer.
Included within this document are warranty registration forms that can assure the customer that any lamp issue regarding the lamp will be covered.
If the distributor is involved in the replacement of failed lamps or ballast there is no requirements that they be an authorized Osram/Sylvania partner. For service of any defective material call 1-800-lightbulb. Reference Lithonia Lighting RT5 series for priority service.
Osram premier 28watt lamps are now available for non-warranty replacement through authorized Osram Sylvania distributors. Through our agreement with Osram we are the only OEM that has the ability to purchase these lamps.
Ballasts have a five-year warranty from the manufacturer.
Osram GEB95, GEB95S, GEB115 and GEB115S ballasts are available only for warranty replacement and are sold exclusively to Lithonia as an OEM. When the first
RT5 ballasts reach their out of warranty point in 2010, the ballast will be made available through Osram distribution.
2.
What is the cost for replacement lamps and/or ballast? Not all distributors are approved to buy from Sylvania.
For lamp or ballast replacement situations that are not covered under warranty:
Premium F28T5 lamps or ballast – Call 1-800-762-7191 and Sylvania will sell the lamp directly to any electrical wholesaler even if they are not an approved distributor.
Standard F14T5, F24T5HO, F54T5HO – Will be replaced under nominal industry practices for replacement lamps and ballasts.
3.
What is the purpose of the plastic film on the refractor? What are the yellowing characteristics of the overlay?
Add additional lamp obscuration.
The overlay material is specifically designed for optical performance and a nonyellowing formula. It has been successfully tested and used in outdoor applications.
See MORE FAQs for details.
4.
Do we offer other fixture mounting or configurations such as flange, metric, or surface?
At this point we do not offer these configurations but they are all under consideration.

5.
What about 347 volt?
At this point the ballast industry has not developed 347-volt ballast for all T5 and
T5HO lamp types. We are able to offer some select wattages in 347 volt that will be handled as specials until such time domestic manufacturers develop these ballast.
Please contact Fluorescent Technical Support or the Fluorescent Help Guide for current 347-volt ballast availability.
6.
Is this new fixture available with lamps or ballasts from other suppliers?
The lamp and ballast were tuned specifically for this product to optimize performance.
No alternative lamp or ballast will be offered except for dimming ballasts designed for the offered lamps such as ECO10.
7.
How do you access the ballast?
The side entry for the quick ballast tray on the side of the RT5 was developed to allow the electrician easy access to the electrical components with direct eye level viewing of the electrical tray. Our research has shown that electricians, by an overwhelming margin, prefer this easy access to the ballast from the adjoining ceiling tile thus environmental entry is not available.
8.
What are the part numbers for replacement parts?
The fluorescent help guide lists parts and DSP for items that may require replacement.
9.
Can we get other shielding media such as perf or louvers?
The RT5 performance and appearance is optimized on the high performance refractor that comes standard on the product, no other shielding media is available for this product.
10.
Is this fixture available in T8?
The RT5 optical system was optimized around the narrow T5 lamp and will not accommodate other lamp types.
11.
Are the new premier lamp and ballast systems utilized on the RT5 available on other
Acuity and Peerless products? Multiple T5 lamps and ballast types on the job site are an issue.
The RT5 lamp and ballast combinations are available in specification grade fixtures from Lithonia, such as Avante, SP8 and MS5. Other fixtures can be ordered with this combination using MP process. RT5 lamp and ballast combinations are also available from Specialty Brands such as Peerless.
12.
Is PAF available on this product?
No, as all painted components on the RT5 are painted after fabrication with a 90 percent reflective matte white finish as a standard feature.

13.
If the premier T5 lamp is rated at 3050 lumen why does the spec sheet have two different lumen ratings for the same lamp, neither of which are 3050. See MORE
FAQs.
14.
What paint finish is used on the RT5?
The same 90% reflective finish diffuse paint that is utilized on the Avante.
15.
Why does the 2 x 4 have special lamps and ballast and the 2 x 2, 1 x 4 uses standard lamps and ballast?
The premium F28T5 lamp was developed exclusively for the high volume 2 x 4 market. The lower volume 2 x 2 and 1 x 4 premium system has not been developed at this time but do complement each other.
16.
Is this product available with full range dimming ballast?
Yes, all dimming ballasts compatible with given lamp types are available on 4' versions and where available on 2' versions.
17.
What is the rated lamp life at 12 hours per start?
Program start ballasts start the lamp so reliably and “gently” that the effect of frequency of starting does not have a significant impact on lamp life. The longer burn hours have essentially the same lamp life as 3 hours per start.
18.
Is this product available with Reloc?
Reloc is an excellent solution for applications there quick any easy installation is preferred. We recommend the QFC system of products.
19.
Are these products suitable for use with Nema type NFG T-bar ceiling systems?
Yes.
20.
How is the inverter mounted in the fixture channel?
Depending on the fixture design, the inverter is typically mounted in the ballast box next to the ballast. In the case of 2 x 2’s the inverter is mounted in the opposite side of the fixture in a second ballast tray.
21.
Is the fixture available without lamps?
No, all fixtures, all configurations ship with lamp installed.
22.
What happens if a standard F28T5 lamp is used rather than a premium T5?
The system will operate with a standard 28-watt lamp but a reduction of 5% in light level can be expected.
23.
What is the ballast factor when using step dimming?
The ballast factor for GEB95S at step level dimming is .35.

The ballast factor for GEB115S at step level dimming is .48.
24.
Can we order this product in a master/satellite configuration?
Only 2-lamp versions of the 28T5 ballasts and 54T5HO ballasts are available. Remote mounting capabilities prohibits the master/satellite of this product.
25.
Is NOM listing available?
Yes, add suffix – NOM.
26.
What is the reflector made out of?
Cold rolled embossed steel, exclusive to Lithonia.
27.
What is the lamp warranty? What is the ballast warranty?
Lamp warranty is 24 months; the ballast is 60 months.
28.
How much heat will go into the return air plenum with a static (non-heat removal)RT5 vs a heat removal 3 lamp T8 fixture?
We have completed testing related to the issue of room side vs plenum heat through fixture calorimetry. This calorimetry study completed by an independent laboratory shows that RT5 introduces 70% of its' heat to the room side and 30% is retained in the plenum. This is a little bit better than the 75/25 industry typical value. This factor is a function of a lower base power consumption (58 watts @277V, 60 Watts
@120V). This better ratio and efficiency translates to lowered electrical consumption and reduced BTU hrs of heat introduced into both the conditioned space and building envelope verses parabolic fixtures, even those with heat removal options. A more detailed explanation and comparison to parabolic fixtures is as follows:
All energy consumed by the fixture eventually is converted to thermal gain. The RT5 introduces 198 BTU hr of heat based on an input wattage of 58 and the conversion factor of 3.41 BTU hr/watt. The industry standard 3 lamp electronic T8 parabolic produces 300 BTU hr of heat based on an input of 88 watts. Obviously without any air removal the RT5 introduces significantly less heat into the building envelope than the parabolic fixture. Calorimetry studies, prepared by Building and Acoustics
Laboratories, show that the RT5 also introduces less heat on the room side than a parabolic fixture equipped with heat removal option. The attached graph of test results indicates that the RT5 introduces 139 BTU hr on the room side, and hence 59
BTU hr (total minus room) on the plenum side. A similar study of the parabolic shows
188 BTU hr on the room side and hence 112 BTU hr into the plenum.

The calorimeter study above also shows the effect of increasing CFM through the parabolic fixture. Since the RT5 is not removing air, it is shown at a constant value. The ideal volume of air flowing through the parabolic fixture was derived experimentally to be 20 CFM at which point 150 BTU hr are introduced to the room side, and 140 BTU hr introduced to the plenum. (The fixture BTU hours drop with airflow of 0 CFM to 20 CFM from 300 BTU hr to 290 BTU hr) Increasing the air flow beyond that amount actually increases the energy consumed by the fixture and increases both room side and plenum heat. (The fixture BTU hours increase with airflow of 20 CFM to 60 CFM from 290 BTU hr to 346 BTU hr) Even at the ideal flow rate of 20 CFM the RT5 fixture introduces 11 BTU hr less heat into the space, and 81
BTU hr less on the plenum side.
In summary, RT5 consumes less electrical energy, reduces heat load on the room side, and reduces plenum heat verses the air return parabolic fixture in all flow rate scenarios - making it a logical choice for all building conditions commonly encountered. The static RT5 data sheet is attached as “2RT5-2x4.pdf”, a full complement can be downloaded at http://www.acuitybrandslighting.com/library/Specification_Sheets/LL/Fluorescent/Vol umetric%20Recessed%20Lighting/Volumetric%20Recessed%20Lighting/
29.
Are air functions available?
The RT5 with CAS option allows air return function. See RT5 CAS data sheet for details.This option will return air through a center air slot, eliminating the need and expense for return air grills. This option at 60 CFM removes about 25 BTU hr of fixture heat from the room side, reducing the heat load into the space to 115 BTU hr from 140 BTU hr. Refer to the chart for air flow rate in CFM vs negative plenum pressure drop in inches of water.
30.
Why does the RT5 have a limited spacing to mounting height ratio or spacing criterion?

In designing lighting fixtures a trade off exists between increased spacing and decreased visual comfort. As spacing is increased more high angle light is required to achieve uniformity on a horizontal workplane. Different applications require varying degrees of visual comfort. Some applications, such as warehouse lighting, require little visual comfort allowing fixtures to be designed with a 55 degree peak. This provides a spacing ratios of up to 2.4. In office applications the goal is to achieve uniformity with visual comfort and without excessive high angle light. We engineered the photometric distribution of the RT5 to provide uniform horizontal light levels on a
2.5 foot high workplane when installed on 8x12 foot centers in a 9 foot ceiling. This is effectively a 1.8 cross spacing, and a 1.2 spacing along.
Why do you publish RT5 with a 1.3 cross spacing and a 1.2 spacing along and still recommend it on wider spacing?
The IES developed the Spacing to Mounting Height or Spacing Criterion as a “rule of thumb” based on mathematical calculations related to the candela distribution of an individual fixture. This was an effective way to safely space fixtures in the days before point-by-point calculations by computer were available to all. (In the old-days we had to prepare point by points with a calculator – or slide rule – using the E =
Cosine Theta (I/D squared) point method.) Now that point by point calculations are available with a few key strokes we can easily show uniformity on the workplane at various spacings. I have attached a point by point analysis at 9 foot ceilings and 2.5 foot workplane showing the RT5 fixture horizontal light level at the common 10 x 8 foot spacings as well as the optimized 12 x 8 foot spacings. The 12 x 8 is actually more uniform than the 10 x 8 because of RT5 volumetric lighting distribution!
31.
Is this product available for NYC or CP?
The standard fixture meets New York City requirements. NYC option on catalog number is not required. Chicago Plenum option is available, specify CP option.
32.
Do these fixtures have integral T-bar clips?
Yes, where code requires SCREW fastened clip we do offer LATC clips.
33.
Since both lamps in a two lamp step dimming fixture operate the same number of hours, doesn't that help in lamp replacement?
Yes, in a two ballast, dual switch operation, the inboard and outboard lamps get uneven use. Thereby building owners are spot re-lamping for two different end-of-life time frames. Step dimming provides even use of both lamps in a fixture maintaining uniform light output and color. Step dimming makes group re-lamping not only cost saving but makes maintenance time easier to schedule.
34.
Need more? See below for more details on lighting calculations, color shift and comparisons to RP-1 criteria.
What does the light diffusing film add to the optical assembly. Is it UV stable?
This film provides us with an efficient and effective means of lamp obscuration, without a loss the optical control. This film rests above the refractor, and the gap between the film and the refractor provides a 2nd and third refractive interface (film to air, air to refractor) where flux from the lamp enters the film and is diffused prior to being shaped by the main refractor. The film as a result becomes a uniform

hemisphere of illumination, as “seen from the refractor”, and it is this uniform hemisphere that is shaped by the refractor into the light and dark bands seen on the surface.
The film that was selected for use in the product is made by Grafix plastics, a company focused on providing optical films for the lighting signage and LED industry. They have been supplying films to the industry for over 40 years. We selected the film based on not only efficiency and effectiveness, but based on durability. We verified Optigrafix's performance specifications by performing standard accelerated life testing on the film here at our laboratory in Conyers. The results of our testing indicates that a barely perceptible color shift is anticipated after 15 years of typical use, equating to 65,000 hours at full output on the high ballast factor
T5. Over this period there will be a 2% drop in transmission, which is treated as an
LDD factor. We predict the useful life of the film to be roughly 20-25 years, at the end of life there will be a more noticeable color shift and the film will exhibit a 4-5% drop in transmission.
35.
Does this system produce 100 lumens per watt?
The lumen output of the Osram Premier lamp at 35 degrees C is 3050 lumens when driven at 28 watts with a 1.0 ballast factor. There is no ballast loss considered in this figure – it is wattage at the lamp. This is more of a marketing metric than a real world figure. The real world is 29 input Watts and 2897.5 lumens at 35 degrees C equating to 99.91 lumens per watt. From a marketing perspective I would call that
100 system lumens per watt.
36.
How do I account for lumen output in my calculations?
The photometric efficiency of the fixture accounts for the increase in lumen output for the T5, just as it takes into account the decrease in lumen output with T8 fixtures. Relative photometry as defined by the IES has us first test the bare lamp at
25 degrees C. This output relates to the 2730 lumens in the file. Next we test the entire fixture. The ratio of the lumen output of the fixture vs the lumen output of the lamp at 25 degrees C is the photometric efficiency. The RT5 outputs 89.9% of the
2730 lumens per lamp. (This is 84 lumens per watt fixture output (LER).)
If you were to plug in the 3050 lumens to the IES file you would double account for the output boost of the lamp, and would predict more light than would be delivered. Using the manufacturers published lumen output at 25 degrees C is the only way to get accurate predictions of light level. We have seen some errors with
T5HO fixtures where the peak lumen output was used in the IES file to calculate light levels. As in the case of the T5 28W the predicted light level will overestimate the footcandles by the ratio of the 25 to 35 C lumen output.
37.
How do I account for ballast factor in my lighting calculations?
The IES recommended practice is to account for fluorescent ballast factor in the light loss factor. For the RT5 we have a single IES file that works for both the 0.95 and
1.15 ballast. (I’d love to say it was engineered that way – but it was a matter of good fortune more than anything.)
For the 0.95 ballast on F28T5 lamp the LLF would be 0.81. This is determined by multiplying .95 BF x .95 Mean Lumens x .90 LDD. (lamp lumen depreciation .95,

80
85
65
75
Luminaire dirt depreciation .90, lamp lumens 2730.) Wattage draw 58 for 277v, 60 for 120v.
For the 1.15 ballast on F28T5 lamp the LLF would be 0.98. This is determined by multiplying 1.15 BF x .95 Mean Lumens x .90 LDD. Wattage draw 71 for 277v, 73 for
120v.
For the 1.15 ballast on F14T5 lamp the LLF would be 1.02 This includes .95 lamp lumen depreciation, .90 luminaire dirt depreciation x 1.22 BF. (Lamp lumen depreciation .93 (Pentron Premier n/a for this lamp), lamp lumens 1220. Wattage draw 39 for 277v, 39 for 120v.
For the F24T5HO using GEB10PS the LLF is .84. BF = 1.00, LLD .93 (Pentron Premier n/a for this lamp), LDD .90, lamp lumens 1760. Wattage 54 for 277v, 55 for 120v.
38.
How is the Luminaire Dirt Depreciation (LDD) figured at .90?
The 0.90 LDD is based on the recent work of NALMCO for lensed fixtures in clean environments. The 30-36 month value was chosen based on 12-15 hour operation per day operation and relamp and cleaning at the recommended 60-70% of rated life. This data was presented in the recently released IESNA/NALMCO RP-36-03.
39.
Why do we recommend RT5 for offices if it does not meet RP-1?
The RT5 is not designed to meet all aspects of the RP1 guidelines. The RT5 is designed to provide adequate illumination of vertical surfaces, while meeting published RP1 values above 80 degrees. The balance of vertical and horizontal illumination delivered without excessive high angle brightness (above 80 degrees) is the essence of the volumetric lighting technique. Delivering volumetric lighting efficiently is what makes RT5 stand out amongst all of the other fixtures with similar distributions (such as Avante).
Vertical Angle RT5 - 0 RT5 - 22.5 RT5 - 45 RT5 - 67.5 RT5 - 90 RT5 - AVE RT5 - MAX RP1 MAX
393
179
495
260
678
314
728
280
715
257
614
268
728
314
300
185
95
30
137
34
140
23
102
19
88
21
118
25
140
34
123
60
40.
80 degree limit on RP1 is based on a linear interpolation between published RP1

values.
One of the principle drivers for RP1’s adoption was the use of the computer monitor in office environments. Since the early days of the glass CRT with high radius of curvature, the computer industry has developed flat screen monitors with antireflective coatings. This coupled with the white background common with today’s software have made products like Avante and RT5 excellent choices for office lighting. Additionally, the new monitors have led to changes in RP1 to make it less restrictive in controlling the photometric distribution to be downward only.
As a note regarding intensity at higher angles, the new IES RP1 states “Some of the new VDT screens are so good at minimizing reflected glare that luminaire luminance does not directly impact screen visibility, and no specific intensity limits apply. However, standard direct glare and eye adaptation issues must still be considered.” Please note that fixtures, such as Optimax, which strictly limit high angle brightness still need to be strongly considered for CAD areas where operators use black background software, and have large curved screens without antireflectance coating.
You may be interested to note that the 45 degree plane on the RT5 is brighter than all others. This squaring of the corners is in part what allows the wider spacing without a significant loss of uniformity.
41.
Does the color shift when we switch-dim the ballast to lower light level?
215mA lamp current -> ~1.15BF and
50mA lamp current -> ~.45 BF
I start with the case of 215mA and a cold spot temperature of 46°C
If you are to drop the current to 50mA, the cold spot will fall to 41°C if the in-fixture ambient remains constant.
This however is not realistic, because with reduced lamp power, the in-fixture ambient will cool, by another estimated 5°C
Therefore, I reduce the question to two cases
Case 1: 215mA lamp current and Cold spot = 46°C
Case 2: 50mA lamp current and Cold spot = 36°C
When you consider the spectra power distributions (suitably normalized) for the two drive conditions, you will see subtle differences in the relative intensities of the atomic emission lines of
Hg from the lamp discharge.
These subtle differences give rise to a color shift of three steps in a color perceptibility diagram.
This color shift will be apparent to most observers as more blue in appearance. The temperature of the cold spot plays a bigger role than the lamp current.
The change in CRI will be +1 for the 50mA case and the change in CCT (color shift) will be +30°K (per Osram/Sylvania)