Philips MHN-TD - Revision history

Andrei.boiu at 21:08, 30 September 2021

2021-09-30T21:08:45Z

← Older revision		Revision as of 23:08, 30 September 2021
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	\| MHN-TD 70W/842 RX7s 1CT \|\| RX7s \|\| 70 W \|\| 5700 lm \|\| Cool White \|\| 4200 K \|\| 80 \|\| 10500 hours		\| MHN-TD 70W/842 RX7s 1CT \|\| RX7s \|\| 70 W \|\| 5700 lm \|\| Cool White \|\| 4200 K \|\| 80 \|\| 10500 hours
	\|-		\|-
	\| MHN-TD 150W/730 RX7s 1CT \|\| RX7s \|\| 150 W \|\| 13800 lm \|\| Warm White \|\| 3000 K \|\| 75 \|\| 10500 hours		\| MHN-TD 150W/730 RX7s-24 1CT \|\| RX7s \|\| 150 W \|\| 13800 lm \|\| Warm White \|\| 3000 K \|\| 75 \|\| 10500 hours
	\|-		\|-
	\| MHN-TD 150W/842 RX7s 1CT \|\| RX7s \|\| 150 W \|\| 12900 lm \|\| Cool White \|\| 4200 K \|\| 85 \|\| 10500 hours		\| MHN-TD 150W/842 RX7s-24 1CT \|\| RX7s \|\| 150 W \|\| 12900 lm \|\| Cool White \|\| 4200 K \|\| 85 \|\| 10500 hours
	\|-		\|-
	\| MHN-TD 250W/842 FC2 1CT \|\| FC2 \|\| 400 W \|\| 20000 lm \|\| Cool White \|\| 4200 K \|\| 85 \|\| 9000 hours		\| MHN-TD 250W/842 FC2 1CT \|\| FC2 \|\| 400 W \|\| 20000 lm \|\| Cool White \|\| 4200 K \|\| 85 \|\| 9000 hours
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	Notes:		Notes:
	* The "RX7s" base is the most popular ~~and mounting caps can be easily found~~ while "FC2" is a specialist item		* The "RX7s" base is the most popular connector for this lamp type while "FC2" is a specialist item;
			* The "RX7s-24" base uses the same end connectors but spaced further apart, for higher power rated lamps;

	== Durability and Repair-ability ==		== Durability and Repair-ability ==

Andrei.boiu: /* History */

2021-09-30T16:34:12Z

History

← Older revision		Revision as of 18:34, 30 September 2021
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	The lamp technology was an improvement of previously developed mercury vapour lamps. The potential for fluorescent powders was mostly exhausted by early 70s which meant that research concentrated on releasing better lamps that produced light directly from the discharge tube. This research was also carried previously but results were modest, as stable compounds with good colour reproduction were found to be quite aggressive and lead to short service life. Sodium, Scandium, Indium, Thallium were attempted as main elements that can offer a balanced light output but they required a specific balance of temperature and pressure to achieve best results. One major limitation was that certain compounds were costly or difficult to manufacture or mix in specific amounts, which meant that suitable results could not be found for many decades. In the late 70s and early 80s most major manufactures were able to center on specific technologies that reached good enough results for general lighting, with predictable performance.		The lamp technology was an improvement of previously developed mercury vapour lamps. The potential for fluorescent powders was mostly exhausted by early 70s which meant that research concentrated on releasing better lamps that produced light directly from the discharge tube. This research was also carried previously but results were modest, as stable compounds with good colour reproduction were found to be quite aggressive and lead to short service life. Sodium, Scandium, Indium, Thallium were attempted as main elements that can offer a balanced light output but they required a specific balance of temperature and pressure to achieve best results. One major limitation was that certain compounds were costly or difficult to manufacture or mix in specific amounts, which meant that suitable results could not be found for many decades. In the late 70s and early 80s most major manufactures were able to center on specific technologies that reached good enough results for general lighting, with predictable performance.

	The MHN-TD range was the result of research aimed at creating lower powered metal hallide lamps that had better colour reproduction and energy efficiency compared with high pressure mercury vapour lamps. The most important limiting factor was that the arc tube had to be formed more evenly at the ends and be reasonably well insulated and heat resistant to ensure reasonable performance. More advanced manufacturing tools and processes had to be developed. ~~As soon as they were available and the~~ arc tube was well built to resist the long term corrosive nature of hallides~~, products were ready for release~~. It was also important to ensure less variations in arc tube geometry as well as temperature profile. This meant that heat reflecting coatings were mandatory for the arc tube. As soon as all these conditions were met, the lamp was released. Products were quite successful on the market until the advent of the much improved ceramic tube metal hallide lamps, around mid 1990s. Although Philips CDM lamps were much more expensive, their better colour reproduction, lamp life and efficiency meant that there was no reason other than cost to choose MHN lamps.		The MHN-TD range was the result of research aimed at creating lower powered metal hallide lamps that had better colour reproduction and energy efficiency compared with high pressure mercury vapour lamps. The most important limiting factor was that the arc tube had to be formed more evenly at the ends and be reasonably well insulated and heat resistant to ensure reasonable performance. More advanced manufacturing tools and processes had to be developed. The arc tube was well built to resist the long term corrosive nature of hallides. It was also important to ensure less variations in arc tube geometry as well as temperature profile. This meant that heat reflecting coatings were mandatory for the arc tube. As soon as all these conditions were met, the lamp was released. Products were quite successful on the market until the advent of the much improved ceramic tube metal hallide lamps, around mid 1990s. Although Philips CDM lamps were much more expensive, their better colour reproduction, lamp life and efficiency meant that there was no reason, other than cost, to choose MHN lamps.

	The only improvement on MHN-TD lamps focused on slightly improved colour reproduction which required higher operating pressure and slightly changed chemistry to ensure stability in this environment to reach color rendering indexes Ra8 of more than 80. Philips was not interested to invest more in quartz metal hallide technology so other world manufacturers like General Electric, Osram and others quickly surpassed it with better performing products so Philips competed only mostly on cost and ensured its market-share with advertising. Even before the advent of LEDs MHN-TD lamp installations were pointless so sales were mostly based on the large install base created in the 1990s.		The only improvement on MHN-TD lamps focused on slightly improved colour reproduction which required higher operating pressure and slightly changed chemistry to ensure stability in this environment to reach color rendering indexes Ra8 of more than 80. Philips was not interested to invest more in quartz metal hallide technology so other world manufacturers like General Electric, Osram and others quickly surpassed it with better performing products so Philips competed only mostly on cost and ensured its market-share with advertising. Even before the advent of LEDs MHN-TD lamp installations were pointless so sales were mostly based on the large install base created in the 1990s.

Andrei.boiu: /* Features */

2021-09-30T11:19:39Z

Features

← Older revision		Revision as of 13:19, 30 September 2021
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	*Internal high pressure quartz discharge tube		*Internal high pressure quartz discharge tube
	*RX7s base or FC2		*RX7s base or FC2
	*Requires matching high pressure sodium ballast
	*Requires external ignitors
	*Color rendering index Ra of 75 to 85		*Color rendering index Ra of 75 to 85
	*Typical lifetime of 9.000 to 10.500 hours		*Typical lifetime of 9.000 to 10.500 hours

Andrei.boiu: /* Features */

2021-09-30T11:04:34Z

Features

← Older revision		Revision as of 13:04, 30 September 2021
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	*Color rendering index Ra of 75 to 85		*Color rendering index Ra of 75 to 85
	*Typical lifetime of 9.000 to 10.500 hours		*Typical lifetime of 9.000 to 10.500 hours
	*Luminous efficacy of 72 to 85 lumens/watt		*Luminous efficacy of 76 to 92 lumens/watt
	*Warm white or Cool white colour designation (3000 or 4200 K colour temperature)		*Warm white or Cool white colour designation (3000 or 4200 K colour temperature)
	*Horizontal operating position (risk of early failure when operating in other positions)		*Horizontal operating position (risk of early failure when operating in other positions)

Andrei.boiu: /* Features */

2021-09-30T11:03:39Z

Features

← Older revision		Revision as of 13:03, 30 September 2021
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	*Requires matching high pressure sodium ballast		*Requires matching high pressure sodium ballast
	*Requires external ignitors		*Requires external ignitors
	*Color rendering index Ra of 76 to 92		*Color rendering index Ra of 75 to 85
	*Typical lifetime of 9.000 to 10.500 hours		*Typical lifetime of 9.000 to 10.500 hours
	*Luminous efficacy of 72 to 85 lumens/watt		*Luminous efficacy of 72 to 85 lumens/watt

Andrei.boiu at 11:02, 30 September 2021

2021-09-30T11:02:46Z

Show changes

Andrei.boiu: /* Greatest features & flaws */

2021-09-30T09:33:20Z

Greatest features & flaws

← Older revision		Revision as of 11:33, 30 September 2021
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	! Features !! Flaws		! Features !! Flaws
	\|-		\|-
	\| High light output in very compact package \|\| Hot operating fixtures		\| High light output in very compact package \|\| Hot operating fixtures, maintenance intensive
	\|-		\|-
	\| High efficiency, good colour rendering \|\| Poor lamp life and colour uniformity		\| High efficiency, good colour rendering \|\| Poor lamp life and colour uniformity

Andrei.boiu: /* Greatest features & flaws */

2021-09-30T09:32:59Z

Greatest features & flaws

← Older revision		Revision as of 11:32, 30 September 2021
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	! Features !! Flaws		! Features !! Flaws
	\|-		\|-
	\| High light output in very compact package \|\| ~~Serious glare risk especially for uncoated lamps~~		\| High light output in very compact package \|\| Hot operating fixtures
	\|-		\|-
	\| High efficiency~~, long life~~, good colour rendering \|\| ~~Quite expensive lamps~~		\| High efficiency, good colour rendering \|\| Poor lamp life and colour uniformity
	\|-		\|-
	\| ~~Mostly omni-directional~~ light \|\| Sensitive to operating position and unbalanced wearing		\| Directional light \|\| Sensitive to operating position and unbalanced wearing
	\|-		\|-
	\| Quick lamp start \|\| Slow restart, requires bulky, heavy, complex lamp gear		\| Quick lamp start \|\| Slow restart, requires bulky, heavy, complex lamp gear

Andrei.boiu: /* Best retro purpose */

2021-09-30T09:30:33Z

Best retro purpose

← Older revision		Revision as of 11:30, 30 September 2021
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	== Best retro purpose ==		== Best retro purpose ==
	Metal Hallide lamps are still widely used on commercial, industrial and architectural lighting but in these applications LED lamps are quickly replacing them due to much better performance, lower energy consumption and easy servicing. Light appearance is coll white or daylight, depending on lamp model, with good colour reproduction and low ultraviolet emission. The lamp can be used indoors as well as outdoors, when intense lighting is required as most surrounding look quite pleasing being light with new lamps.		Metal Hallide lamps are still widely used on commercial, industrial and architectural lighting but in these applications LED lamps are quickly replacing them due to much better performance, lower energy consumption and easy servicing. Light appearance is coll white or daylight, depending on lamp model, with good colour reproduction and low ultraviolet emission. The lamp can be used indoors as well as outdoors, when intense lighting is required as most surrounding look quite pleasing being light with new lamps. With the most common gear, an electromagnetic ballast along with an ignitor, flicker is noticeable.

	These type of double-ended lamps were used sometimes for lighting exterior areas, especially for higher powered lamps but the most frequent application was indoor accent lighting with lower wattages. The lamp was relatively affordable (for a metal hallide lamp) and compact, having a successful niche until LED lamps appeared. Since they are very compact light sources it should be noted that heat output is very high, making the lamp unsuitable for open-air operation, seriously limiting flexibility. Another very important limitation is caused by the mandatory operating position and relatively short lamp life. While lamp warm up time is low, with the lamp achieving high output quite quickly, they are slow to restart, 10 minutes pauses not being uncommon. Both high pressure mercury vapour as well as sodium vapour ballasts can be used if provided with a suitable ignitor.		These type of double-ended lamps were used sometimes for lighting exterior areas, especially for higher powered lamps but the most frequent application was indoor accent lighting with lower wattages. The lamp was relatively affordable (for a metal hallide lamp) and compact, having a successful niche until LED lamps appeared. Since they are very compact light sources it should be noted that heat output is very high, making the lamp unsuitable for open-air operation, seriously limiting flexibility. Another very important limitation is caused by the mandatory operating position and relatively short lamp life. While lamp warm up time is low, with the lamp achieving high output quite quickly, they are slow to restart, 10 minutes pauses not being uncommon. Both high pressure mercury vapour as well as sodium vapour ballasts can be used if provided with a suitable ignitor.

Andrei.boiu: /* Durability and Repair-ability */

2021-09-30T09:29:34Z

Durability and Repair-ability

← Older revision		Revision as of 11:29, 30 September 2021
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	== Durability and Repair-ability ==		== Durability and Repair-ability ==
	Generally, ~~sodium vapour~~ lamps ~~were very durable~~ and ~~most modern products were released~~ with ~~even longer typical lifetimes. This is mainly due to the fact~~ that ~~the main market of street lighting pressured producers~~ to ~~cot servicing costs which means that reliability improvements were mandatory~~. ~~Unfortunately, due to~~ the ~~way that almost all lamps are designed, they age in a different way compared with other~~ light ~~sources~~. ~~Sodium slowly permeates~~ the ~~ceramic arc tube meaning~~ that the ~~lamp voltage raises as~~ the ~~lamp ages, making it harder to remain in stable operation after startup~~. This ~~creates the well known on-~~and~~-off lamp cylcles that repeats every couple of minutes, accelerating as the~~ lamps ~~is close~~ to ~~demise. Eventually, the lamp does not start but this happens after a long cycling and gear stress that might span over months or even a whole year~~.		Generally, metal hallide lamps fare quite poorly in terms of reliability. The aggressiveness of metal hallides and their reliance on a specific pressure and temperature requirement for vaporization and light output with a specific output, means that lamp to lamp colour shifts are quite noticeable. Aging amplifies the colour drift and light output differences. As the lamp is very compact and has high temperature hot-spots means that fixtures are noticeably degraded and especially affects gaskets and the front frame of the reflector housing. This means that waterproofing is frequently degraded and lamps are rarely suited to operate outdoors unless old fixtures are carefully maintained.

	~~Compared with modern LED lamps, sodium lamps compare favourably but they have a much poorer light output and require careful wiring. In most cases operational cost is lower~~ as ~~less powerful LED luminaries can be used since all useful light is directed downwards compared with~~ the ~~inefficient fixtures used on most sodium vapour lamps. Ballast and ignitors can survive tens of years if properly protected against direct rain or snow exposure. A complex circuitry means that~~ lamp ~~servicing~~ is ~~difficult~~ and ~~there are major risks due to improper wiring on servicing as large voltages~~ may ~~be present~~. ~~70, 100~~ and ~~150 watt lamps are very well built~~ and ~~they~~ were ~~highly popular~~. ~~Ignitors can be potentially repaired but the lack of schematics~~ means that ~~they can~~ be ~~repaired only by experienced persons~~ and ~~are, thus, mostly discarded when not working~~.		Due to the lamp being compact as well as frequent indoor applications heat degradation of the lamp gear is quite common and some design constraints may limit replacement of some ballasts and ignitors without modifying mounting points. Electromagnetic and electronic gears have been available during manufacturing but electromagnetic ballasts and ignitors were the most common ones due to lower cost. This means that special care should be taken for proper insulation and wiring and that the lamp life is slightly reduced.

	== Greatest features & flaws ==		== Greatest features & flaws ==