Sylvania Engineering Bulletin - Lumalux & Unalux Lamps 1977

8/3/2019 Sylvania Engineering Bulletin - Lumalux & Unalux Lamps 1977

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EngineeringBulletin 0-348'----- -L-171 e laces9175J __

Lumalux & Unalux Lamps


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TABLE O F CON TEN TSLUMALUX LAMPS

Theory of Operation .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3Lamp Construction , , , . 4Illumination Characteristics .,., , , 5Ballasts . ~ ~ . ~ ~ . 4 ~ ~ ~ , ~ ' ~ ~ t f ~ t, t t t t t t t t ttl t t t t t t t t t t tIt t t 6Operating Characteristics , .. ,." , , , , 6

Theory of Operation , , , , , .. , , , 7Lamp Construction ,. , , . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. 8Illumination Characteristics , 9Ballasts , ,." , .. , , .. 99

UNALUX LAMPS

Operating CharacteristicsAPPLICATION

Coated HPS Lamps , ,', , , , . , .. , , , . ,1 0Remote Ballasting , , 11Warning ................. , .. , 11Operating Instructions .. , ,., ,. , . ,11

TABLES OF PERFORMANCE DATA1. Lumalux. . , .. , , , 122. Unalux , .. ,. , , 15


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LUM ALUX LAM PSTHEORY OF OPERATION

The Lumalux lamp is the most efficient member ofthe high intensity discharge (HID) lamp family.Light is produced by passing an electric currentthrough vaporized sodium under pressure at hightemperature. Its physical, electrical and photo-metric characteristics are different from other HIDlamps.The advantages of a high pressure sodium arc dis-charge have been known for quite a while. Thedevelopment of a practical, long lived lamp for general lighting using the high pressure sodium dis-charge required a major breakthrough in materialtechnology. The development of a new ceramic,polycrystalline aluminum oxide, was the key tomaking the high pressure sodium lamp a practicalreality. This material is extremely resistant to at-tack by sodium vapor and can stand the very highoperating temperatures required for maximum effi-ciency and yet has excellent transmissioncharacteristics for visible light.

The principal radiating element in the arc of theLumalux lamp is sodium Mercury is included as abuffer gas for color and voltage controL There isalso a small quantity of xenon gas in the arc tubewhich is used to initiate the starting sequence.Since long and narrow arc tube geometry is re-quired for maximum efficiency and xenon is usedas a starting gas and since starting probes are notused, extremely high voltages are necessary forlamp ignition. The starting function is accom-plished by an electronic starter circuit which worksin conjunction with the magnetic component ofthe ballast. The starter supplies a short high voltagepulse on each cycle or half cycle of the supply volt-age. The pulse is of sufficient amplitude and dura-tion to ionize the xenon gas and initiate thestarting sequence of the lamp. Specific values ofthe pulse width and amplitude required for the var-ious sizes of Lumalux lamps are shown in Table 1.

COATED TUNGSTEN ELECTRODEELECTRIC DISCHARGETHROUGH SODIUM VAPOR

ARC TUBE MOUNTFig. 1. Electrical circuit of Lumalux lamp.

IIf 11 I TYPICAL BALLASTI_V CHARACTERISTIC"...- -,

- ~:;;;I"-- - - - - -.... IY I I: /1 I : -, I. , A . . . . I I I "I I I II I I 1I 1 I II I II II I

475

MINIMUMLAMPVOLTS

280

MAXIMUM LAMP WATTS

MAXIMUMLAMP VOLTS

IMINIMUM LAMP WATTSI 'II 1 I II I I 1 '01 II~, I , I , Io I 67 84 95 122 140 151LAMP VOLTS -- ...

Fig. 2. Lamp Voltage-Wattage Limits for the 400 Watt Lumalux3


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The ballast also has to provide the usual ballastingfunction such as providing sufficient open circuitvoltage to sustain the arc, limiting lamp operatingcurrent and regulating the lamp power as a func-tion of both lamp and line voltage. A simple con-nection diagram of a Lumalux lamp and ballast isshown in Figure 1.The' high pressure sodium lamp is made with an ex-cess of sodium which is in the form of an amalgamwith mercury. Over a period of operating time,some of the sodium is lost to the arc streamthrough several mechanisms. As the ratio of so-dium to mercury pressure changes the arc voltagerises. Eventually the lamp operating voltage willrise to a level beyond the ballast's ability to sus-tain. When this happens, the lamp will start, warmup to full brightness and then extinguish. This se-quence is repeated regularly and is called cycling.This sympton is the normal end of life failuremode of high pressure sodium lamps.

Figure 2 shows a preferred lamp voltage - lampwattage ballast characteristic which tends to con-trol the rate of voltage rise. The negative slope be-yond rated voltage decreases wattage with in-creasing lamp voltage thus decelerating the voltagerise.The warm-up period for a Lurnalux lamp to reachfull brightness is about 3 to 4 minutes - somewhatless than that of a mercury or Metalarc lamp. Dur-ing warm-up, there are several changes in the colorof the light. Initially, there is a very dim, bluish-white glow produced by ionized xenon which isquickly replaced by a typical blue, brighter mer-cury light. With an increase i l 1 . brightness, there is achange to monochromatic yellow which is char-acteristic of sodium at low pressure. Then as thepressure in the arc tube increases, the lamp comesto full brightness with a golden white light. Shouldthere be a momentary interruption of power, therestrike time is approximately one minute.

LAMP CONSTRUCT IONThe basic parts of a Lumalux lamp are shown inFigure 3. Similar to mercury and Metalarc lamps, ithas two bulb construction with an outer bulb"jacket" and an inner "arc tube". The ceramic arctube contains the electrodes, sodium-mercuryamalgam and a small amount of xenon. The outerbulb of weather-resistant glass protects the arc tube

DOME MOUNT SUPPORT

MONOLITHIC END SEALS

it--+-- CERAMIC ARC TUBEWEATHER RESISTANT GLASS

ARC TUBE MOUNT

0---+-- VACUUM

NECK MOUNT SUPPORT

NICKE L PLATED BRASSDATE RECORDI NG BASE

Fig. 3. Basic parts of Lumalux lamp.

from damage and contains a vacuum which reducesconvection and conduction heat loss from the arctube to insure high efficacy.The arc tube in the Lumalux lamp is long and slen-der and is made from a ceramic polycrystalline alu-minum oxide. The geometry is dictated by the re-quirement for high temperature to vaporizesodium. The ceramic is required to withstand thesehigh temperatures. The tube is translucent and isideally suited to high intensity discharge light gen-eration and transmission with a transmittance ofapproximately 95% in the visible wave lengths ..Be-cause of its freedom from impurities and smallpores, it is extremely resistant to the corrosive ef-fects of hot sodium. Sodium at these elevated tem-peratures deteriorates quartz and similar materialsvery quickly.

CERAMIC ARCTUBE

BACKWOUND COATEDTUNGSTENE L ECTRODE

CERAMICSEALING BUTTON

SLIDING JOINT

Fig.4. Monolithic construction.4


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Lumalux lamps are constructed with monolithicarc tubes and end seals which are schematicallyrepresented in Figure 4. The monolithic design usesa ceramic material identical to that of the body ofthe tube to seal the major area of the end. Aniobium tube through the center of the end is usedto make the electrical connection to the electrodeand to seal the discharge vessel. Most of the signifi-cant sodium loss mechanisms operate in the area ofthe seals.Minimization of frit sealing material whichis used to cement the metal to the polycrystallinealuminum oxide is achieved with this design. Thisreduces or eliminates much of the area in whichsodium can be lost to the arc stream and results in alamp that has a very low voltage rise over life andassures long lamp life.

The concept of locating the amalgam reservoir in-side the discharge tube is incorporated along withthe monolithic seal. The reservoir will form in thecoldest spot within the arc tube and typically willbe found behind the electrodes. By eliminating theneed for an external reservoir, the Lumalux lampcan be operated in any position. This provides twosignificant advantages to the user. First the lampdoes not have to be ordered in a base up or basedown version thereby simplifying stocking proce-dures and, secondly, the lamp cannot be mis-installed. If the correct lamp is selected, it will bein the correct operating position regardless oforientation.

The efficiency of the high pressure sodium lamp iscritically dependent upon a specific vapor pressureof the sodium within the tube. To maintain this va-por pressure, the amalgam cold spot temperaturemust be the same regardless of the arc tube con-struction. Since the seal of the inside reservoirmonolithic design is contiguous with the amalgamcold spot, the seal must operate at the amalgamcold spot temperature. In the case of the externalreservoir metal end cap design, the amalgam coldspot is remote from the seal. A significant tem-perature gradient must exist between the sealand the amalgam cold spot with the seal operatingat a significantly higher temperature than the ex-ternal reservoir cold spot. Thus it is easily under-stood that the seal of an external reservoir metalend cap design must necessarily run hotter than theseal of the inside reservoir monolithic design. Thehigher temperature tends to accelerate the reactionbetween the sealing material and sodium thus tyingup sodium and increasing the sodium loss from thearc stream. This of course leads to a higher rate oflamp voltage rise for the external reservoir design.Thus the internal reservoir monolithic design arctube significantly reduces the rate of sodium lossand, as a result, provides a very long lived lamp.Alignment of the arc tube within the outer jackethas been improved by a centering rod. A slidingjoint (Fig. 4) allows normal travel of the arc tubedue to thermal expansion and also provides excel-lent resistance against arc tube displacement due tomechanical shock.

ILLUMINATION CHARACTERIST ICSOF LUMALUXEfficacyThe most important feature of Lumalux lamps istheir high efficacy. Initial efficacy is better thantwice that of an equivalent wattage mercury lamp.The output of the Lumalux lamps range from the70 watt in excess of 80 lumens per watt to the1000 watt which provides 140 lumens per watt.Spectral Energy DistributionThe older low pressure sodium vapor lamps prod-uce a yellow light with the visible energy radiatedat two closely spaced wavelengths of -589.0 and589.6 nanometers in the yellow region of the spec-trum. At the high temperature in the arc stream ofthe Lumalux lamp, however, the normal sodium ra-diation is altered and becomes a continuous spec-tral energy distribution, as shown in Figure 5. Tothe eye, the light produced appears to be goldenwhite in color.

\ J . Y . VICLfl BW E _l_ G R E E N Y UL OW O RA NG f REO

I Jr u J ~__ ,~Ll r L".,~ -

'"

650 700WAVE lENGTH . .. . . NANON . .E T ERS

Fig. 5. Spectral energy distribution ofthe 400-Watt Lumalux lamp.The radiation from Lumalux lamps is unlike thatfrom other HID lamps in that there is no significantenergy in the ultraviolet regions.

5


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LUMALUX LAM P BALLASTSThe Lumalux lamp has electrical characteristicsthat are considerably different from those of otherHID lamps. Operating voltages and currents do notcorrespond to those of similar wattage. mercury orMetalarc lamps. As a result, special ballastingequipment is required.A ballast for a Lumalux lamp must provide thehigh voltage starting pulse, limit lamp current andregulate lamp power as a function of line voltageand lamp operating voltage. A ll Lumalux ballasttypes have two basic parts: an electronic starting

circuit and the magnetic component. Lamp andballast requirements are governed by the applicableANSI specifications. There are differences betweenballasts and the specific application conditionsshould be carefully considered when choosing aballast.When a lamp fails or is removed, the ballast is sub-jected to its starting sequence continuously. Thiscan have an adverse effect on ballast life. Thespecific ballast manufacturer's recommendationsshould be followed regarding the time in which adefective or removed lamp should be replaced.

OPERATING CH ARACTER IST ICS OF LUMALUX LAMPSLamp LifeIn common with other H.I.D. sources, theLumalux lamp has a long average life. The 400watt mortality or life expectancy curve is shown inFigure 6. Like mercury and metalarc lamps the lifeis affected by burning hours per start and is longestwith continuous burning. Table 1 lists the averagerated life at 10 hours per start.L um en O utput and M aintenanceThe Lumalux lamp has the highest efficacy of anypolychromatic general lighting source. The lightoutput gradually declines throughout life, as shownin Figure 7. The mean lumens during' life are ap-proximately equal to 90 percent of the initial val-ues.Bu rn ing Po si ti onA significant added benefit from the SylvaniaMonolithic seal construction is that it is no longernecessary to stock separate lamp types for base upand base down burning. A single type in each watt-age will now fulfill all application requirementsregardless of the lamp burning position. This featurenot only simplifies the ordering and stocking oflamps but also eliminates any possibility of error ofapplication.W arm-up and R estr ike Tim eThe Lumalux lamp reaches full light output inabout 3-4 minutes as described earlier in this bul-letin, and the restrike time after a momentary in -terruption is approximately 1minute.Fixture Effect Voltage RiseThere may be an increase in lamp operating voltagewhen the lamp is operated in a fixture as opposedto a lamp that is operated in free air. This effect is

called fixture voltage rise. This rise is due to thereradiating effect of the fixture back upon the arctube. Fixture voltage rise limits are shown in Table1.Excessive voltage rise will cause reduced lamplife.100 r-:-_


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UN ALUX LAM PSTH EORY O F OPERA TIO N

The Unalux lamp is another high intensity dis-charge lamp and is a member of the high pressuresodium family. Unlike Lumalux lamps, the Unaluxis specifically designed to operate on mercury lampballasting equipment. As a result, its electrical char-acteristics and most of its physical characteristicsare similar to the equivalent mercury lamp it is de-signed to replace. Photometric characteristics arecompletely different from mercury and are verymuch like standard Lumalux lamps.The electrical circuit of the Unalux lamp is shownschematically in Figure 8. The sketch indicates thatthe arc tube is very similar to the Lumalux arctube. Unlike the Lumalux lamp, an electronicstarter board is not required. By design, the Unaluxlamp has a carefully balanced mixture of rare gaseswhich operates in conjunction with a starting aidthat is wound around the arc tube. This combi-nation insures starting of the Unalux lamp at themercury lamp open circuit voltages.Unalux lamps will operate satisfactorily on lag typemercury ballasts and most series streetlighting mer-cury ballasts. Unalux lamps operate at lower watt-age on the mercury ballast equipment than do themercury lamps. Operating wattage savings are gen-erally in the range of 10% to 15%.Unalux lamps are very efficient. On a lumen perwatt basis, they almost double the performance ofmercury lamps. The design changes required toprovide operating characteristics compatible with

STARTINGAID

mercury ballasting equipment result in an efficacyslightly less than the comparable Lumalux lamp.The Unalux lamp is generally considered a retrofitlamp but this does not have to be the case. Thereare situations where it is economically competitivewith Lumalux lamps particularly where capital ex-penditures are a problem. Mercury lighting equip-ment is generally less costly than conventional highpressure sodium equipment. It should also be rec-ognized that the mercury ballast types that will op-erate Unalux lamps are more efficient than stan-dard high pressure sodium equipment. Another advantage in using Unalux lamps. is that maintenanceand troubleshooting are simplified because thestarter circuit is not required.The warm-up period for a Unalux lamp to reachfull brightness is three to four minutes. This is lessthan that of a mercury or a Metalarc lamp. Duringwarm-up, there are several changes in color of thelight. Initially, there is a bright red glow created bythe neon which is one of the constituents of therare gas fill. This red is shortly replaced by the typ-ical blue mercury light. As the lamp continuesthrough its warm-up cycle the blue is replaced by amonochroma tic yellow radiation which is char-acteristic of sodium vapor at low pressure. As timepasses, both pressure and temperature increase andthe lamp comes to brightness with a golden whitelight. Should there be a momentary interruption ofpower, the restrike time is approximately one min-ute.

RARE GASPENNINGMIXTUREMONOLITHIC SEALWITH HEAT SHIELD

LAGTYPE

MERCURYI-"'"""t::J---I~---f~BALLAST

CIRCUIT BREAKERCE RAM I C ARC TUBEWITH MONOLITHIC

SEALSFig. 8. Electrical Circuit of the Unalux Lamp

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LAMP CONSTRUCTION

M O N O L I T H I CSEALr-'1----~:-------WI T H HEAT SHIELDI-- -+- CERAMICARC

T U B Er - - - - r - - - - - - - - - V A C U U M

STARTING~~--------+--------AID

WEATHER~----RESISTANT

GLASS-H-f------,j~---- CIRCUIT

BREAKER

The basic parts of Unalux lamp are shown in Fig-ure 9. Similar to mercury and Metalarc lamps, ithas two bulb construction with an outer bulb"jacket" and an inner "arc tube". The ceramic arctube contains the electrodes, a sodium mercuryamalgam, and argon and neon gas, The outer bulbof weather-resistant glass protects the arc tubefrom damage and contains a vacuum which reducesconduction and convection heat loss from the arctube to insure high efficacy.The BT (bulged tubular) outer jacket style used formercury lamps is used for Unalux lamps. This isdone to maintain light center length and maximumover all length so that the lamp is physically compatible with mercury equipment on a retrofit basis.The startinqaid is coiled around the arc tube and iselectrically connected through a thermal circuit

breaker to the electrode at the opposite end of t h etube. When potential is applied, ionization "takesplace between the starting aid and the adjacentelectrode causing the gas to become sufficientlyconductive to allow the arc to strike from electrodeto electrode. As the lamp warms up to operatingtemperature, the circuit breaker opens and isolatesthe starting aid eliminating the possibility of electro-chemical reactions with hot sodium vapor andassuring long lamp life and reliable performance"The Unalux lamp is manufactured with the mono-lithic seal. This design is discussed in detail in theLumalux section of this bulletin, The major bene-fits derived from the monolithic seal are long lamplife due to low voltage rise and the universalburning position feature which eliminates dual in-ventories and misinstallation.

NICKELPLATED~--------------BRASSDATE

RECORDINGBASE

Fig. 9. Basic Parts of the Unalux Lamp

8


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ILLUM IN ATIO N C HARAC TE RIST IC S O FUN ALUX LAM PSEfficacyThe Unalux lamp is an attractive alternative formany lighting jobs where increased light levelsand/or energy savings are required.Unalux lamps are very efficient converters of elec-trical energy into light. On a lumen per watt basis,they are approximately twice as efficient as themercury lamps that they replace. In addition, theyuse ten to fifteen percent less electrical energy thanmercury lamps.Spectral. Energy DistributionThe older low pressure sodium vapor lamps pro-duce a yellow light with the visible energy radiatedat two closely spaced wavelengths of 589..0 and589.6 nanometers in the yellow region of the spec-trum. At the high temperature in the arc stream ofthe Unalux lamp, however, the normal sodium ra-diation is altered and becomes a continuous spec-tral energy distribution, as shown in Figure 10. To

VIOLET 81.tJE I GREEN I 'n. ORANGE REO

If- . ,~\J L J [ J J . ,[

..> 0 4S0 5b o 5~0 80 0 650 7b o ~Fig. 10. Spectral EnergyDistribution of the360 Watt Unalux Lamp

the eye, the light produced appears to be goldewhite in color.It should also be noted that the Unalux lamproduces no significant energy in the ultravioleregion.

UNALUXLAM P BALLASTSUnalux lamps are designed to operate on 240 and277 volt mercury reactor ballasts, mercury lagautotransformer ballasts, and most mercury seriesballasting equipment. These ballast types have the

required lamp voltage - lamp wattage characteristic; i.e., reduction of lamp wattage as lamvoltage increases past rated. This tends to keewattage relatively constant over lamp life.O PE RATING CH ARACTE RIST ICS O F UNALUX LAM PS

Lamp lifeIn common with other HID sources, the Unaluxlamp has a long average life. The 360 watt mor-tality of life expectancy curve is shown in Figure11. Like mercury and Metalarc lamps the life is af-fected by burning hours per start and is longestwith continuous burning. Table 2 lists the averagerated life at 10 hours per start.100 - - r---- - . . . . . . . . . . . . _ _ - . . . . . ~ >:;1 E'" i=Q,~ - ( . ) ' "C I "C . .: If 0 '"- If I-~a: '" '" !; '" . . . .~c c : '" '" ~ Et; ~ ~ ~ ~i= IIIc : : :12


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PERFORMANCE DATATable 1 lists the physical, electrical and photometric characteristics, as well as the starting requirementsof Lumalux lamps.

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PERFO RMA NC E DA TATable 1 lists the physical, electrical and photmetric characteristics, as wen as the starting requirementsof Lumalux lamps.

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PERFO RMA NC E DATATable 2 lists the physical, electrical and photometric characteristics, as.well as the starting requirementsof Unalux lamps .

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SYLVANIA Industrial/CommercialLighting l < ! m

Location SalesOfficesITO OBTAIN SALES ANOTECHNICAL INFORMATION)

Zip Code

DistributionCentersITO ORDER LAMPS AND TO OBTAIN SHIPPINGINFORMATION) WAREHOUSE STOCKS MAINTAINEDIN THESE LOCATIONS. Zip Code

Atlanta, Ga. 2115 Sylvan Rd., S. W404-7621781 30344 303442115 Sylvan Rd., S. W404-762-1 781

Boston, Mass. 60 Boston Street, Salem, MA617 7771900 0197025 Dewberry Lane, Gardenvi lle, Ind. Park716-668-6111 14224uffalo, N. Y.

25 Dewberry Lane, Gardenvil le Ind. Park716668-6125 14224

105 Andover Street , PO. Box 377, Danvers, MA.617-777-1900 01923

Charlotte, N. C. 3811 North Davidson sr.. P.O. Bol

Documents

Sylvania Engineering Bulletin - Lumalux & Unalux Lamps 1977