Philips HPI-T and HPI-T Plus - Revision history

Andrei.boiu: /* Features */

2021-10-02T08:49:41Z

Features

← Older revision		Revision as of 10:49, 2 October 2021
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	*Luminous efficacy of 84 to 89 lumens/watt		*Luminous efficacy of 84 to 89 lumens/watt
	*Cool white or daylight colour designation (4500 or 6700 K colour temperature)		*Cool white or daylight colour designation (4500 or 6700 K colour temperature)
	*One of the following (risk of early failure when operating in other positions):
	*Horizontal operating position		*Horizontal operating position

Andrei.boiu: /* Features */

2021-10-02T08:48:38Z

Features

← Older revision		Revision as of 10:48, 2 October 2021
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	*Color rendering index Ra of 65		*Color rendering index Ra of 65
	*Typical lifetime of 20.000 to 24.000 hours		*Typical lifetime of 20.000 to 24.000 hours
	*Luminous efficacy of 72 to 85 lumens/watt		*Luminous efficacy of 84 to 89 lumens/watt
	*Cool white or daylight colour designation (4500 or 6700 K colour temperature)		*Cool white or daylight colour designation (4500 or 6700 K colour temperature)
	*One of the following (risk of early failure when operating in other positions):		*One of the following (risk of early failure when operating in other positions):

Andrei.boiu: /* Suitability */

2021-10-02T08:29:27Z

Suitability

← Older revision		Revision as of 10:29, 2 October 2021
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	== Suitability ==		== Suitability ==
	HPI-T lamps are much more effective for flood lighting but they require specific fixtures and have higher surface temperature, making them more susceptible to damage when improperly handled. Chinese branded lamps are much worse in all performance and quality metrics with shorter useful life, worse colour reproduction and and efficiency as a proper, stable mix of hallides required huge research investment that was too costly for Chinese producers.		HPI-T lamps are much more effective for flood lighting but they require specific fixtures and have higher surface temperature, making them more susceptible to damage when improperly handled. Chinese branded lamps are much worse in all performance and quality metrics with shorter useful life, worse colour reproduction and and efficiency as a proper, stable mix of hallides required huge research investment that was too costly for Chinese producers. The difference between HPI-T and HPI-T Plus is mostly attributed to the ability of using either a high pressure sodium or mercury vapour lamp gear with minimal impact on service life and light output.

	The best choice ~~are~~, probably, the 250 watt lamps as larger powered lamps are too powerful for most purposes. This ~~lamp wattage~~ was also cheaper as they were highly popular. Electro-magnetic ballasts or conventional gears are plentiful and can be used interchangeably with all manufactured lamps for a specific wattage and ignitors' performance is less critical as on high pressure sodium lamps. Lower rated power output gears can be used, but it is not recommended as colour reproduction and lamp lifetime will be reduced while higher powered ones damage the lamp due to over-stressing and is highly dangerous.		The best choice is, probably, the 250 watt lamps as larger powered lamps are too powerful for most purposes. This product was also cheaper as they were highly popular. Electro-magnetic ballasts or conventional gears are plentiful and can be used interchangeably with all manufactured lamps for a specific wattage and ignitors' performance is less critical as on high pressure sodium lamps. Lower rated power output gears can be used, but it is not recommended as colour reproduction and lamp lifetime will be reduced while higher powered ones damage the lamp due to over-stressing and is highly dangerous.

	Used lamp gears might work but old lamps are never desirable as they degrade much quicker than mercury vapour and sodium lamps. Rusted ballast may still operate but are a potential hazard while old, used lamps, may not have much useful life left and they may already exhibit some colour light emission issues. New old-stock lamps are the best choice, if available.		Used lamp gears might work but old lamps are never desirable as they degrade much quicker than mercury vapour and sodium lamps. Rusted ballast may still operate but are a potential hazard while old, used lamps, may not have much useful life left and they may already exhibit some colour light emission issues. New old-stock lamps are the best choice, if available.

Andrei.boiu: /* Review */

2021-10-02T08:27:18Z

Review

← Older revision		Revision as of 10:27, 2 October 2021
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	== Review ==		== Review ==
	These ~~high pressure sodium vapour~~ lamps are ~~compact light sources that are viable~~ for ~~wide area~~ lighting~~. Their poor~~ colour reproduction ~~and large output means that they are entirely suited to outdoor lighting or greenhouses as grow light~~. ~~Compared with fluorescent~~ lamps ~~they~~ were very ~~compact~~, ~~having great performance at low temperatures~~. ~~A very long lifetime, that was around 16 to 25 times higher than tungsten lamps,~~ and ~~almost double that of some fluorescent lamps, meant that these lamps are~~ well ~~suited for use~~ in ~~places where~~ lamp ~~replacement was costly, as in high bay lighting, street lighting, tunnel~~ lighting.		These metal hallide lamps are better suited for outdoor lighting due to their high power rating and good colour reproduction. Long service lifetime is also another major feature of these HPI-T lamps. Large wattage fixtures were very popular especially for flood lighting with boxy, asymmetric or symmetric lighting patterns. The most popular power ratings were 250 and 400 Watts. The lamp itself fares well in terms of light output but the point light source nature of the lamp relegates it to accent or directional rather than general lighting.

	High pressure sodium lamps had higher light output, almost double, of mercury vapour lamps while having very low quality colour reproduction. This means that mercury vapour lamps were still suited for areas where colour reproduction was moderately important and there was still an advantage from compact light sources. However, street lighting ~~was~~ a ~~very important market~~ as ~~the lamp's efficiency ensured cost savings in labour~~ and electricity use, after the 1970s oil crisis. There were some advances in colour reproduction with different lamp technology but standard lamps were not favourite of industrial, workshop lighting commercial premises. The light spectra was, however, highly beneficial for plant growth.		Exterior lighting is a good application as most gardens and outside areas are well showcased. The lamps themselves do release some heat meaning that closed fixtures are not well suited if not specifically built for this purpose. Care should be taken when using these metal-hallide lamps as they are sensitive to the operating position especially when inside enclosed fixtures. Compact, boxy symmetric and asymmetric fixtures were popular. Improper heating of lamp can destroy it prematurely and present a safety hazard so special precaution should be exercised. Even if lamp warm up time is low, achieving high output quite quickly, they are slow to restart, 10 minutes pauses not being uncommon.

	The ~~inherent flicker of mains voltage~~ lamps ~~is very low even with conventional gear due to the fact that a large amount of light happens due to thermal emission and balance of the temperature of internal arc tube. There were~~ some ~~electronic medium frequency gear similar with ones used on fluorescent lamps but they were very costly. However, sodium and metal hallide gears are generally compatible,~~ meaning that ~~most sodium lamps can~~ be ~~easily replaced with compatible wattage~~ metal hallide lamps that have a much better colour appearance, sacrificing some energy efficiency due to different lamp technology. The requirement for ignitors along ballasts while it raises total cost and increases complexity, as well as raising the risk due to passing thousands of volts through some wires, means that fixtures have a clear advantage of maximum useful light and restart in case of power failure in almost one minute.

	~~Fixtures~~ are ~~generally compact, considering the light output made available, but are generally heavy due~~ to the ~~bulky electromagnetic gear being used. There are directional and omni-directional~~ fixtures ~~that are suited to various purposes~~. ~~In street lighting, the well known cobra-head style lamppost was used~~, and ~~they may still be available for purchase~~. ~~They were only moderately effective as light covered a large area but a considerable amount of light was lost due to the fixture directing some~~ of it ~~upwards, with no control. Omni-directional fixtures were used in residential areas~~ and ~~parks, where ambience was more important than efficiency~~. ~~Indoor fixtures were centered on the typical high-bay or~~ low~~-bay types due to their application in greenhouses where light has to be directed entirely downwards. Other fixtures were compact~~, ~~having a boxy design~~, ~~with a symmetrical or asymmetrical lamp placement that was suited for flood lighting. These type of lamps were used outdoor~~, ~~for floodlighting. There were no home designed fixtures as these lamps were never used in home environments~~.

	== Operation ==		== Operation ==

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

2021-10-02T08:22:33Z

Greatest features & flaws

← Older revision		Revision as of 10:22, 2 October 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 \|\| Serious glare risk
	\|-		\|-
	\| High efficiency, long life, average colour rendering \|\| Quite expensive lamps		\| High efficiency, long life, average colour rendering \|\| Quite expensive lamps

Andrei.boiu: /* Technical details */

2021-10-02T08:22:03Z

Technical details

← Older revision		Revision as of 10:22, 2 October 2021
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	\|}		\|}

	Notes:		Notes: "MASTER" designation should point at better performing lamps but it is meaningless in this lamp range.
	* some lamps have an integrated internal starter and do not require an external ignitor, presented with the "S" ~~designation;~~
	* MASTER designation should point at better performing lamps but it is meaningless in this lamp range.

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

Andrei.boiu: /* Features */

2021-10-02T08:21:12Z

Features

← Older revision		Revision as of 10:21, 2 October 2021
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	*Cool white or daylight colour designation (4500 or 6700 K colour temperature)		*Cool white or daylight colour designation (4500 or 6700 K colour temperature)
	*One of the following (risk of early failure when operating in other positions):		*One of the following (risk of early failure when operating in other positions):
	*Horizontal operating position ~~(all HPI-T lamps)~~		*Horizontal operating position

	== Lamp control gear ==		== Lamp control gear ==

Andrei.boiu: /* Features */

2021-10-02T08:20:14Z

Features

← Older revision		Revision as of 10:20, 2 October 2021
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	*E40 base		*E40 base
	*Color rendering index Ra of 65		*Color rendering index Ra of 65
	*Typical lifetime of 20.000 to 24.000 hours ~~(only HPI-T lamps)~~		*Typical lifetime of 20.000 to 24.000 hours
	*Luminous efficacy of 72 to 85 lumens/watt		*Luminous efficacy of 72 to 85 lumens/watt
	*Cool white or daylight colour designation (4500 or 6700 K colour temperature)		*Cool white or daylight colour designation (4500 or 6700 K colour temperature)

Andrei.boiu: /* Lamp control gear */

2021-10-02T08:19:33Z

Lamp control gear

← Older revision		Revision as of 10:19, 2 October 2021
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	*Requires external gear (similar to mercury vapour lamps) and appropriate wiring:		*Requires external gear (similar to mercury vapour lamps) and appropriate wiring:
	** Philips BHL or compatible reactive inductive ballast with matching power rating		** Philips BHL or compatible reactive inductive ballast with matching power rating
	** Philips SI or compatible parallel ignitor for 5000 Volt pulses ~~(except "S" designated lamps)~~		** Philips SI or compatible parallel ignitor for 5000 Volt pulses
	** May require power factor correction capacitor for balancing line load		** May require power factor correction capacitor for balancing line load

Andrei.boiu at 08:18, 2 October 2021

2021-10-02T08:18:56Z

← Older revision		Revision as of 10:18, 2 October 2021
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	** Philips SI or compatible parallel ignitor for 5000 Volt pulses (except "S" designated lamps)		** Philips SI or compatible parallel ignitor for 5000 Volt pulses (except "S" designated lamps)
	** May require power factor correction capacitor for balancing line load		** May require power factor correction capacitor for balancing line load
	\|}
	\|style="vertical-align:top" \|		\|style="vertical-align:top" \|
	\|
	[[Image:Philips HPI-T 1000W.jpg\|Philips HPI-T 1000W]]		[[Image:Philips HPI-T 1000W.jpg\|Philips HPI-T 1000W]]
	\|}		\|}