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Lighting Tranformers
- consist of 3 single-phase, delta-delta connection
- if 1 fails, the remaining 2 will still carry 58% of initial load capacity
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Light Sources
- incandescent
- fluorescent
- glow
- low-pressure sodium lamps
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Incandescent Lamps
- consist of tungsten filament supported by a glass stem
- rated - in watts, amperes, volts, candlepowers, or lumen
- classified - according to their shape, finish, and type of base
- less than rated voltage - prolongs life and decreases light output
- higher than rated volatage - shorten life and increase light output
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Flourescent Lamps
- oxide-coated filament sealed in each end
- contains mercury and small amount of argon gas
- inside surface is coated with flourescent phospor
- black dot - measn gas-filled tube
- 3 standard size - 8, 15, and 20 watts
- use aboard ship - hot-cathode, preheat starting type
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Glow Lamps
- contains inert gas such as neon or argon
- used as indicator or pilot lights for equipments
- color depends on the gas
- neon - red
- argon - blue
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Glow Lamps Advantages
- small
- rugged
- long life span
- negligible current consumption
- can be use on standard lighting ckts
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Low-Pressure Sodium Lamps
- installed in aircraft carriers (flightdeck and hangar areas)
- contains sodium
- starting gas - neon with small argon, xenon, and helium
- color - monochromatic yellow
- starting time - 7 to 15 min
- output cant be dimmed
- colors cant be changed
- - store horizontally to keep sodium evenly in original containers
- - dispose by breaking the lamp and pour water to deactivate sodium
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Classification of Fixtures
- watertight
- nonwatertight
- pressure-proof
- exploxionproof
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