Selection for Street Light Luminar-(PART-3)

Type of Street Light Lamp:

Street lighting Lamps normally used three types High intensity discharge (HID) lamps, High pressure sodium vapor (HPSV), Metal halide (MH), or Mercury vapor (MV).
However Mainly Lamps for Street lighting can be divided into three main categories (1) incandescent lamps and (2) luminescent gaseous discharge lamps. (3) LED
The lamps used in street lighting today are mostly High Intensity Discharge (HID) lamps that include high pressure sodium, low pressure sodium, high pressure mercury and metal halide lamps.
In order to reduce the emission of greenhouse gases, the use of energy efficient lamps such as Light Emitting Diodes (LED) for Street lighting has increased.

The incandescent or filament lamp was for many years the most commonly used. However, its low efficacy and short rated life have made it undesirable for new installations.
Advantage:
Inexpensive
Available in Different Configurations & Colors
No warm up is required
Easily controlled
Dis Advantage:
Inefficient ( 10-25 lumens/watt )
Short lamp life
Vibration sensitive
Over-voltage sensitive

At many places tube lights are used for Street Light lighting.
Tube lights in general are available in lower wattages and they cannot produce the same kind of brightness as a Halogen or Sodium Vapour lamp. So they should not be used to replace Halogen lamps, as they cannot produce the same amount of brightness
Lamps are available in the following configurations: T5,T8,T10,T12,T17

Halogen lamp is incandescent Type lamp. It has a tungsten filament filled with halogen gas.

Application: For outdoor areas/ parking lot lighting

HID lamps in general require an external ballast to operate. HID lamps usually take between 1 and 5 minutes to reach full brightness, and if there is a dip in electricity, these lamps will shut off.
HID lamps must cool sufficiently to re strike, which usually takes from 1 minute to 10 minutes.
There are Mainly Two type of High discharge lamp
(1) High Pressure Lamp (HP)
(A) Mercury Vapor Lamp(MV)
(B) Metal Halide Lamp
(C) Sodium Lamp
(2) Low Pressure Lamp (LP)
(a) Mercury Fluorescent Tube
(b) Sodium Lamp
Ballasts, which are required by both fluorescent and HID lamps, provide the necessary circuit conditions (voltage, current, and wave form) to start and operate the lamps.
HID Lamps Characteristics
All HID lamps utilize an internal arc tube and outer envelope construction
All HID lamps require ballast for operation.
All HID lamps require warm up period
All HID lamps require cool-down period before they can re-strike

It is oldest Type of Lamp in HID Type.
Prior to the introduction of HPS lamps, MV was the most commonly used light source in highway applications. The MV lamp produces a bluish white light and is not as efficient as the HPS lamp.
Lamp sizes: 50,70,100,150,175,200,250,350, 400, and 450W
Advantage:
Mercury vapor lamps can provide certain low cost options for replacing less efficient lamps such as incandescent lamps without changing the fixtures.
Pulse start MH lamps utilize an improved ballast design to improve operation.
Higher efficacy

Faster warm-up and re-strike longer life
Better color uniformity
Energy & maintenance savings (15%)
Disadvantages:
Due to their lower efficacy and poor color rendition they are seldom used in new construction. Color shift toward the end of lamp life
Some lamps are designed for enclosed fixtures only
Orientation sensitive ( horizontal vs. vertical )
Light Color: Bluish white ,Pale Blue-Green Color
Efficiency: Lowest Efficiency in HID Type (30 to 65 lumen/Watt)
Lamp Life: Long Life ( 2400 Hours)
Initial Cost: Low initial Cost
Warm up Time: Faster warm-up and re-strike longer life
Application: For outdoor areas/ parking lot lighting ,farm light, fish pond

MH lamps produce better color at higher efficiency than MV lamps. However, life expectancy for MH lamps is shorter than for HPS or MV lamps.
They also are more sensitive to lamp orientation than other light sources.
Metal Halide bulbs are as energy efficient as Sodium Vapour lamps.
Metal halide lamps are similar in construction to MV lamps. Some MH lamps can be operated off Mercury Vapor ballasts.
MH lamps offer a number of advantaged over MV lamps.

Light Color: A crisp clear white lights
Efficiency: Quit Efficient (80 lumen/Watt)
Lamp Life: Less (6000-20000 hrs)
Warm up Time:2-3 minutes, hot re-strike 10-20 minutes.
Application: It is used where color rendering is critical, such as car lots, service stations, athletic fields, industrial manufacturing.

High pressure sodium lamps are used for both interior and exterior applications and mainly used for street lighting.
HPS is higher efficient and better choice than metal halide for street light applications.
HPS is the energy efficient options for halogen lamps as they provide double the amount of brightness for the same amount of wattage.
HPS lamps differ from mercury and metal-halide lamps because HPS do not contain starting electrodes, the ballast circuit includes a high-voltage electronic starter.
The arc tube is made of a ceramic material

Advantages:
If a Halogen is replaced with Sodium Vapour lamp, 20-25% savings can be achieved.
Disadvantages:
Their brightness is highest in the canter (just below the pole) and is lesser on the outside
Light Color: golden-yellowish-White, Orange color light.
Advances in electronics now make it possible to dim HPS fixtures in a cost effective manor such as production areas and warehouses.
Efficiency: Quit Efficient (80 to 100lumen/Watt)
Lamp Life: Long Life (2400 Hours)
Warm up Time: 10 minutes, hot re-strike within 60 seconds
Operating sodium at higher pressures and temperatures makes it highly reactive
Application:Mostly use on Street lighting.
plant growing in green houses