Lighting Reference Guide – HID Lamps & LPS Lamps

11 HID Lamps & LPS Lamps

a. Mercury Vapour (MV) Lamps

Note:

Use of MV Lamps should be discouraged. They are no more efficient than fluorescent applications in indoor applications, in outdoor applications they should be replaced with one of the other gas discharge lamps. The disposal of mercury vapour lamps require special methods because of the mercury inside the lamp. Local disposal authorities should be contacted for approved disposal methods.

Construction

  • The mercury vapour (MV) lamp, or mercury lamp, is a high–intensity discharge (HID) lamp.
  • Light is produced by current passing through the mercury vapour at relatively high pressure.
  • The MV lamp is the oldest HID source.
  • An MV lamp, like all HID lamps, consists of an arc tube enclosed in an outer bulb (a bulb in a bulb).
  • The arc tube contains the mercury vapour, a starting gas (argon) and the electrodes.
  • The outer bulb contains an inert gas (nitrogen) to prevent oxidation of internal parts and to maintain the operating temperature.
  • The outer bulb also provides an inner surface for an optional phosphor coating.

Typical Construction and Circuit of an MV Lamp

MV Lamp

Operation

  • When the lamp is turned on, a voltage is applied to initiate an arc between a starting electrode and the nearby main electrode, which vaporizes the mercury.
  • The “warm–up” time until the lamp develops full light output is five to seven minutes.
  • The “restrike” time (time required to start up after a momentary power interruption) is about 10 minutes.
  • During operation, when the electric arc is formed the mercury vapour emits light and ultraviolet (UV) radiation.
  • UV radiation can be converted to light by a phosphor coating on the inside of the outer bulb.
  • MV lamps, like all HID lamps, require ballasts.

Sizes

  • Standard MV, 40 to 1,000 watts.
  • Self–ballasted MV, 160 to 1,250 watts.

Rated Average Life

  • 24,000 hours + for most MV lamps.

Colour

  • There are two types of MV lamps, clear and phosphor–coated.
  • Clear MV lamps have a bluish–white colour and poor colour rendering.
  • Phosphor–coated MV lamps have a better colour appearance and colour rendering.

Efficacy

  • MV lamps are the least efficient of all HID lamps.
  • MV lamps are more efficient than incandescent lamps, but less efficient than fluorescent lamps.
  • Efficacies range from 10 to 63 lumens per watt.

Applications

  • MV lamps are no longer specified for new construction or retrofit due to poor efficacy.
  • The disposal of mercury vapour lamps will require special disposal methods because of the mercury inside the lamp. Local disposal authorities should be contacted for approved disposal methods
  • Interior industrial applications.
  • Street lighting, security lighting, floodlighting.
  • Retail shops, indoor shopping malls, restaurants, cafeterias, air/bus terminals, lobbies, foyers, gymnasiums, banks, barns.

MV vs Other High Intensity Discharge Lamps

  • It may be more economical to replace MV lamps with metal halide or high pressure sodium (HPS) lamps, which have much better luminous efficacy.
  • These direct replacement lamps may improve the efficacy by 70%+.
  • Refer to chapters on MH lamps and HPS lamps
  • MV lamps are rarely used in new lighting systems.

Shapes

Shapes

Lamp Data

Lamp
Designation		     Lamp
Watts		 Including Ballast
1 Lamp
(2 Lamps)		 Rated
Lamp
Life (hrs)		 Initial
Lumens		 Initial
Lumens
per
Watt		     Lumens
Mean
Lumens		     Mean
Colour
per Watt		     Temp
Deg
K		   CRI   LLD
Clear
H43 75 75 95    (190) 24,000 2,800 29.5 2,430 25.6 7,000 22  0.73
H38 100 100 125    (250) 24,000 4,100 32.8 3,380 27.0 7,000 22  0.78
H42 125 125 155    (310) 24,000 5,700 36.8 5,020 32.4 7,000 22  0.88
H39 175 175 210    (410) 24,000 7,900 37.6 7,400 352 6,800 22  0.88
H37 250 250 290    (580) 24,000 12,000 41.4 10,800 37.2 5,900 22  0.81
H33 400 400 450    (880) 24,000 20,500 45.6 18,700 41.6 5,900 22  0.84
H35 700 700 775 (1,550) 24,000 41,000 52.9 37,300 48.1 5,900 22  0.81
H36 1000 1,000 1,100 (2,200) 24,000 57,500 52.3 50,600 46.0 5,900 22  0.78
Phosphor Coated
H36 50/DX 50 63    (125) 16.000 1,575 25.0 1,260 20.0 4.000 43  0.61
H33 75/DX 75 95    (190) 16,000 2,800 29.5 2,250 23.7 4,000 43  0.72
H38 100/DX 100 125    (250) 24,000 4,200 33.6 3,530 28.2 4,000 43  0.70
H32 123/DX 125 155    (310) 24.000 6,350 41.0 5,270 34.0 4,000 43  0.76
H39 175/DX 175 210    (410) 24,000 8,600 41.0 7,650 36.4 4,000 43  0.70
H37 250/DX 250 290    (580) 24,000 13,000 44.8 11,000 37.9 4,000 43  0.62
H33 400/DX 400 450    (880) 24,000 23,000 51.1 18,400 40.9 4,000 43  0.70
H35 700/DX 700 775 (1,550) 24,000 44,500 57.4 34,500 44.5 4,000 43  0.64
H36 1000/DX 1,000 1,100 (2,200) 24,000 63,000 57.3 47,500 43.2 4,000 43  0.65
Self–Ballasted (for replacement of incandescent)
H160   160     160 12.000 2,300 14.4 l,600 10.0      
H250   250     250 12,000 5,000 20.0 3,750 15.0      
H350   450     450 16,000 9,500 21.1 7,125 15.8      
H750   750     750 16,000 14,000 18.7 10,500 14.0      
Notes: • Mounting for position–oriented lamps is indicated as HOR (horizontal) or VER (vertical) only.
• When position is unspecified the lumen output value given applies to vertical mounting.
• Slightly reduced values will result if lamp is mounted in other positions.
• Life and mean lumen ratings for HID lamps are based on 10 hours per start.
• H indicates MVlamp (H for Hg – the chemical symbol for mercury).
• These lamps are being phased out.

b. Metal Halide Lamps

Construction

  • The metal halide (MH) lamps are generally similar in construction to the MV lamps.
  • They operate on the same principle as all HID lamps.
  • The main difference is that the arc tube contains metallic salts (scandium and sodium) in addition to the mercury vapour and argon gas.
  • Like all HID sources, MH lamps consist of an arc tube enclosed in an outer bulb.

Typical Construction and Circuit of an MH Lamp

Typical Construction and Circuit of an MH Lamp
Typical Construction and Circuit of an MH Lamp
Note: Pulse Start lamp uses higher open circuit voltage for starting.
 

Operation

  • Warm–up time is about 4 minutes.
  • Restrike time is about 10–12 minutes standard – 4–7 min. for pulse start.
  • MH lamps generally cannot be burnt in any position.
  • Horizontal–burning lamps have the arc tube bowed upward, to follow the natural curve of the arc stream in the horizontal burning position.

Available Wattage

  • Sizes range from 40 to 1,500 watts.

Rated Average Life

  • 6,000 hours (70 W) to 20,000 (400 W).

Colour

  • MH lamps are available in both clear and phosphor–coated versions.
  • Clear lamps produce a slightly bluish–white colour and have a CRI far superior to MV lamps.
  • Phosphor–coated lamps produce a warmer–looking white light and an improved CRI.
  • MH lamps exhibit some colour variation from lamp to lamp and normally change colour throughout their life.

Efficacy

  • The MH lamp is the most efficient source of “white” light available.
  • Efficacies range from 50 to 110 lumens per watt.
  • MH lamps are more efficient than MV and fluorescent lamps, but less efficient than HPS and low pressure sodium (LPS) lamps.
  • CRI – 65–70

Applications

  • Similar to MV lamps.
  • MH lamps are effective replacements for MV lamps.
  • Large wattages are used for floodlighting, streetlighting, large industrial areas and sports arenas.
  • Smaller wattages are used in merchandising areas, assembly spaces, schools and public buildings.
  • Clear lamps are used for colour TV broadcasting, colour photography, industrial/commercial lighting.
  • Phosphor–coated lamps are used for industrial/commercial indoor lighting, area lighting.

Brands

Major manufacturers carry a variety of metal halide lamps.

Shapes

Shapes

Numbers indicate maximum diameter in eighths of an inch.

MH Lamps Safety

  • Fixtures with MH lamps should be fully enclosed.
  • MH and MV lamps operate under high pressure and very high temperatures and there is a possibility that the arc tube may rupture.
  • When this happens, the outer bulb surrounding the arc tube may break, and particles of extremely hot quartz (from the arc tube) and glass fragments (from the outer bulb) create a risk of personal injury or fire.
  • Sylvania and General Electric have issued warnings to the users of their MH lamps.
    • Sylvania's warning:
      – All MH lamps should be used in enclosed fixtures.
      – Enclosures must be made of suitable material, such as
         tempered glass.
    • General Electric’s warning:
      – All MH lamps in horizontal, or more than 15% off–vertical
         position, should be used in enclosed fixtures.
      – 175 W, 250 W, 1500 W MH lamps, regardless of position,
         should be used in enclosed fixtures.
      – 325 W, 400 W, 950 W, 1000 W MH lamps, in vertical
         position, or less than 15% off–vertical    position, can be used
         in open fixtures.
      – In continuously operating systems, turn the lamps off once
         a week for at least 15 minutes.
      – MH lamps near the end of their life may not start.
      – Relamp fixtures at or before end of rated life.

Direct Replacement of MV Lamps

  • Some MH lamps are designed as direct replacements for MV lamps and use the existing MV lamp fixtures and ballasts.
  • In comparison with the MV lamps, the efficacy may be improved by 70%+, but the rated average life is generally shorter.
  • An energy conservation retrofit.
Lamp Designation
Lamp
Designation		 Lamp
Watts		 Total
Watts
Including
Ballast
1 Lamp
(2 Lamps)		 Rated
Lamp
Life
(hrs)		 Initial
Lumens		 Initial
Lumens
per
Watt		 Mean
Lumens		 Mean
Lumens
per
Watt		 Colour
Temp
K  		 CRI   LLD
Standard Clear
M175 175 200            10,000 14.000 70.0 10,800 54.0 4,500 65   0.73
M250 250 275            10,000 20,500 74.5 17,000 61.8 4,700 65   0.72
M400 400 450    (880) 20,000 34,000 75.6 25,600 56.9 4,000 65   0.69
M1000 1,000 1,075 (2,160) 12.000 110,000 102.3 88,000 81.9 4,000 65   0.72
M1500 1,500 1,6200           3,000 155,000 96.3 142,500 88.5 3,900 65   0.88
Standard Phosphor–Coated
M175/C 175 200            10,000 14.000 70.0 10,200 51.0 3,900 70   0.67
M250/C 250 275            10,000 20,500 74.5 16,000 58.2 3,900 70   0.67
M400/C 400 450    (880) 20,000 34,000 75.6 24,600 54.7 3.700 70   0.63
M1000/C 1,000 1,075 (2,160) 12,000 10,000 102.3 84.000 78.1 3,400 70   0.67
High Performance Clear
M175/HOR 175 200            10,000 15,000 75.0 12,000 60.0 4,700 65   0.70
M400 400 450    (800) 20,000 40,000 88.9 32,000 71.1 4.500 65   0.71
M1000/VER 1,000 1,075 (2,160) 12,000 125,000 116.3 100,000 93.0 3,500 65   0.72
High Performance Phosphor–Coated
M175/C/HOR 175 200            10,000 15,000 75.0 11,300 56.5 4,200 70   0.66
M400/C 400 450    (800) 20,000 40,000 88.9 31,000 68.9 3,800 70   0.64
M1000/C/VER 1,000 1,075 (2,160) 12,000 125,000 116.3 95,800 89.1 3,100 70   0.64
MH Operable on Mercury Vapour Ballast
Clear
M325 325 375            20,000 28,000 74.7 18,200 48.5 4,000 65   0.57
M400 400 450            15,000 34,000 75.6 20,400 45.3 4,000   0.45
M1000 1,000 1,100            12,000 107,000 97.3 85,600 77.8 3,800   0.75
Phosphor–Coated
M325/C 325 375            20,000 ;28,000 74.7 17,600 46.9 3,700 70   0.54
M400/C 400 450            15,000 34,000 75.6 19,600 43.6 3,700   0.45
Notes: • Mounting for position–oriented lamps is indicated as HOR (horizontal) or VER
  (vertical) only.
• When position is unspecified the lumen output value given applies to vertical
   mounting. Slightly reduced values will result if lamp is mounted in other positions.
• Life and mean lumen ratings for HID lamps are based on 10 hours per start.

Ceramic Metal Halide Lamps

General Description

  • In order to counter the poor colour consistency of metal halide lamps over life, lamp manufacturers have combined the ceramic arc tube from HPS lamps with the gas mix and metals used in Metal Halide lamps to produce Ceramic Metal Halide (MH) lamps.
  • These lamps offer significant advantages over typical Metal Halide lamps and are available in PAR packages to fit smaller recessed and track–mounted luminaires.
  • These sources and luminaires offer significant savings compared to incandescent lamps typically used in retail (stores) and display lighting.

Comparison

120 W Halogen PAR 38 Flood:
25°, 3,000 hrs, 7,700 MBCP, 1,800 lm, 95 CRI

39 W MH PAR 30 Flood (55W with electronic ballast):
30°, 9,000 hrs, 7,400 MBCP, 2,300 lm, 85 CRI

c. High Pressure Sodium Lamps

Construction

  • High pressure sodium (HPS) lamps are HID lamps that ionize sodium vapour.
  • Like all HID sources, HPS lamps consist of an arc tube enclosed in an outer bulb.
  • The arc tube contains xenon (starting gas), sodium and mercury.
  • The mercury is in the form of an amalgam with the sodium.
  • HPS lamps do not have starting electrodes because of the arc tube’s small diameter.
  • The arc tube is made of a ceramic that can withstand high temperatures (1,300°C) and resist the corrosive effects of hot sodium.

Typical Construction and Circuit of an HPS Lamp

Typical Construction and Circuit of an HPS Lamp

Operation

  • The ballast provides a high–voltage pulse (2,500 V) for one microsecond for lamp start.
  • This high–voltage spike establishes the xenon arc between the main electrodes.
  • Mercury and sodium then vaporize rapidly and maintain the arc.
  • Warm–up time is three to four minutes.
  • Restrike time is about one minute–shortest restrike time of all HID sources.

Sizes

  • HPS lamp sizes range from 35 to 1,000 watts.

Rated Average Life

  • 24,000 hours for most HPS lamps.

Colour

  • The light colour of HPS lamps is usually described as golden–white.
  • HPS lamps are available in either clear or diffuse–coated versions.
  • Improved colour lamps operating under increased pressure have better colour rendering properties at the expense of lamp life and luminous efficiency.

Efficacy

  • HPS lamps are the most efficient source of golden–white light.
  • HPS lamps are more efficient than MH lamps, but less efficient than Low Pressure Sodium (LPS) lamps.
  • Efficacies range approximately from 50 to 140 lumens per watt.
  • Efficacy increases with lamp size.

Applications

  • ll applications where colour is less important.
  • Clear lamps are used in roadway lighting, floodlighting, industrial lighting, area lighting, airport lighting.
  • Coated lamps are used in area and floodlighting, security lighting, industrial and commercial indoor lighting and parking lots.

Shapes

Shapes

Lamp Designation
Lamp
Designation		 Lamp
Watts		 Total
Watts
Including
Ballast
1 Lamp		 Rated
Lamp
Life
  (hrs)		 Initial
Lumens		 Initial
Lumens
per
   Watt		 Mean
  Lumens		 Mean
Lumens
per
   Watt		   Colour
Temp
Deg
K  		 CRI   LLD
Clear
S 35 35 55 16,000 2,250 40.9 2,025 36.8 1,900 21   0.84
S 50 50 70 24,000 4,000 57.1 3,600 51.4 1,900 21   0.81
S 70 70 95 24,000 5,800 61.1 5,220 54.9 2,100 21   0.83
S 100 100 130 24,000 9,500 73.1 8,500 65.8 2,100 21   0.79
S 150 150 190 24,000 16,000 84.2 14,400 75.8 2,050 21   0.84
S 200 200 250 24,000 22,000 88.0 19,800 79.2 2,100 21   0.84
S 250 250 305 24,000 27,500 90.2 24,750 81.1 2,100 21   0.84
S 400 400 475 24,000 50,000 105.3 45,000 94.7 2,100 21   0,86
S 1000 1,000 1,095 24.000 140,000 127.9 126,000 115.1 2,100 21   0.84
Diffuse–Coated
S 35/D 35 55 16,000 2,150 39.1 1,935 35.2 1,900 21   0.84
S 50/D 50 70 24,000 3,800 54.3 3,420 48.9 1,900 21   0.81
S 70/D 70 95 24,000 5,400 56.8 4,860 51.2 1,900 21   0.83
S 100/D 100 130 24,000 8,800 67.7 7,920 60.9 2,100 32   0.83
S 150/D 150 190 24,000 15,000 78.9 13,500 71.1 2,100 32   0.83
S 250/D 250 305 24,000 26,000 85.2 23,400 76.7 2,100 32   0.84
S 400/D 400 475 24,000 47,500 100.0 42,750 90.0 2.100 32   0.80
Colour Improved Clear
150 150 190 7,500 13,600 71.6 12,240 64.4 2,400 65   0.27
200 200 250 7,500 19,000 76.0 17,100 68.4 2,400 65   0.87
250 250 305 10,000 25,500 82.0 22,500 73.8 2,400 65   0.87
Colour Improved Diffuse–Coated
150 150 190 10,000 13,000 68.4     2,300 70   0.89
250 250 305 10,000 23,000 75.4     2,300 70   0.89
400 400 475 10,000 39,500 82.1     2,300 70   0.89

Direct Replacement of MV Lamps

  • Some HPS lamps are designed as direct replacements for MV lamps and use the existing MV lamp fixtures and ballasts.
  • In comparison with the MV lamps, the efficacy may be improved by 70%+, but the rated average life is generally shorter.
  • Often used in energy conservation retrofits.
  • For lamp information, refer to the table below:
Direct Replacement of MV Lamps
Lamp
Designation		 Lamp
Watts		 Total
Watts
Including
Ballast
Watts		 Rated
Lamp
Life
(1 Lamp)		 Initial
(hrs)		 Initial
Lumens
per
Lumens		 Mean
Watt 		 Mean
Lumens
per
Lumens 		 Colour
Temp
Watt 		 CRI   LLD
HPS Operable on Mercury Vapour Ballast
Clear
150 I50 I80 12,000 13,000 72.2   11,700 65.0 1,800   0.85
215 215 250 12,000 20,000 80.0   18,000 72.0 2,060   0.85
360 360 405 16,000 38,000 93.8   34,960 86.3 2,060   0.88
880 880 930 12,000 102,000 109.7   91,800 98.7 2,100   0.67
Phospho–Coated
150 150 I80 12,000 12,000 66.7   10,800 60.0 1,800   0.85
330 330 380 16,000 30,000 78.9   27,000 71.1 2,000 30   0.73
360 360 405 16,000 36,000 88.9   32,400 80.0 2,060   0.88
Notes:  • HPS lamps can be operated in any position without affecting lumen output.
• Life and mean lumen ratings for HID lamps are based on 10 hours per start.

d. Low Pressure Sodium Lamps

Construction

  • Low pressure sodium (LPS or SOX) lamps are HID lamps, operated at low pressure, in which the arc is carried by ionized sodium vapour.
  • LPS lamps are more closely related to fluorescent than HID lamps, since they have a low–pressure, low–intensity discharge source and a linear lamp shape.
  • An LPS lamp consists of a U–shaped arc tube enclosed in a clear tubular outer bulb.
  • An indium oxide coating on the inside of the outer bulb reflects most of the infrared radiation back to the arc tube.
  • The arc tube is enclosed in a vacuum to minimize heat loss.
  • The lamp is designed to fully utilize its generated heat.
  • The arc tube can maintain an operating temperature of about
    2,600° C, resulting in an extremely high luminous efficacy.

Operation

  • At start–up, the current is carried by the starting gas (neon and argon) producing a red glow.
  • As the lamp warms up, sodium is vaporized and the discharge begins to exhibit the characteristic yellow colour of an LPS lamp.
  • Warm–up time is about nine minutes.
  • Restrike time is less than one minute.

Typical Construction

Typical Construction

Sizes

LPS lamp sizes range from 18 to 180 watts.

Colour

  • The light of an LPS lamp has a yellow colour
    (monochromatic).
  • The colour rendition is very low–it turns every colour to either yellow or muddy brown.
  • The CRI value does not apply to this lamp.

Efficacy

  • The LPS lamp has the highest efficacy of all light sources.
  • Lamp efficacies range from 100 to more than 180 lumens per watt.
  • Efficacy increases with lamp size.
  • The LPS lamp has the highest efficacy because it emits monochromatic yellow light close to the peak of the eye sensitivity curve.

Applications

  • The LPS lamp is generally not used in new construction, but it may be found in existing sites.
  • All applications where colour rendering is not important.
  • Roadway lighting
  • Security lighting
  • Area floodlighting
  • Warehouses

Lamp
Designation		 Total
Watts
Including
Ballast
Watts		 Rated
Lamp
Life
1 Lamp		 Initial
(hrs)		 Initial
Lumens
per
Lumens		 Mean
Watt		 Mean
Lumens
per
Lumens		 Colour
Temp
Watt		 Deg
K 		LLD
SOX 18 18 32 14,000 1,800 56.3 1,800 53.7 1,740 1.03
SOX 35 35 60 18,000 4,800 80.0 4,800 76.2 1,740 1.03
SOX 55 55 80 18,000 8,000 100.0 8,000 95.2 1,740 1.03
SOX 90 90 125 18,000 13,500 108.0 13,500 103.1 1,740 1.03
SOX 135 135 170 18,000 22,500 132.4 22,500 126.4 1,740 1.03
SOX 180 180 215 18,000 33,000 153.5 33,000 146.7 1,740 1.03
Notes: • The wattage and lumen output for LPS lamps will increase by approximately
  7% and 5% respectively, by the end of lamp life.
• Due to the monochromatic nature of LPS lamps, CRI is not applicable.

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