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Worcester, MA 01603
Tel. 1 (888) 455-2800
Fax 1.508.363.2900

The LED Authority

Aleddra 18W 48" Emergency T8 4000K LED Bulb, Ballast Bypass

SKU: YSH-T812-Y01-18(G13)4000K | Ordering Code: YSH-T812-Y01-18(G13)4000K

$105.99 $92.29 per Bulb
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Product Highlights

  • Estimated life of 45.7 years based on 3 hours use per day
  • No lead or mercury means easy and environmentally safe disposal

Lighting Facts Per Bulb

Brightness 1890 lumens
Estimated Yearly Energy Cost $2.17
Based on 3 hrs/day, 11¢/kWh
Cost depends on rates and use
Based on 3 hrs/day45.7 years
Light Appearance
4000 K
Energy Used18 watts
  • Clearance

Aleddra emergency double-ended T8 plastic bulb comes with an integrated emergency battery back-up that can be used as a regular T8 bulb and an emergency bulb. It has a test button and indicator lamps so that it is safe with fire protection standards. It has over-charging and over-discharging protection which ensure the lifetime of the batteries (800 times charging and discharging). This emergency T8 bulb is a cost-effective option for various emergency lighting applications such as office buildings, schools, hotels, apartment buildings, corridors and stairs. Can be used with the emergency feature when the other bulbs in the fixture are T8 LED bypass bulbs.

Line driven - The ballast must be bypassed when present

The fixture will need to be double-ended wired - hot to one end and neutral to the other end.

Can be used with shunted or unshunted sockets. Unshunted socket example is Leviton # L13351-U

  • 2-in-1 bulb - Regular T8 lighting and emergency lighting
  • Built-in lithium batteries
  • Test button and battery check indicator
  • Must operate on a separate circuit
  • Emergency time - 90 minutes
  • Uses 3 watts and has 428 lumen output when used with the battery
  • Double-ended: Can be used with shunted or unshunted sockets
  • When using a 2+ lamp fixture one bulb can be wired to emergency constant power for emergency use or the entire fixture can be if needed
Full Specs


Aleddra LED Lighting

Model Number


Energy Used

A rating, expressed in watts, to indicate the rate at which a lamp consumes energy. Also known as wattage value.
Energy Used
18 Watts


A measure of "electrical pressure" between two points. The voltage specification of an incandescent lamp is the electrical "pressure" required to drive it at its designed point. The "voltage" of a ballast (e.g. 120 V) refers to the line voltage coming from the power source and is connected to the ballast.


The end (or ends) of the lamp that fits into the socket.
Medium Bipin


Wiring configuration a bulb can work with. Can be single-ended, double-ended or both.
Double Ended

Bulb Shape

The description of the general appearance of a lamp/bulb consists of a letter(s) followed by a number. The letter indicates the shape of the bulb and the number relates to the diameter of the bulb in eighths of an inch. For example, a common household bulb is the A-19. The bulb is "A" shape and the diameter would be nineteen 8ths of an inch, or 2 3/8".
Bulb Shape

Bulb Color

The color of the light produced by a bulb
Bulb Color
Cool White


Color Rendering Index is an international system used to rate a lamp's ability to render object colors. The higher the CRI (based upon a 0-100 scale) the richer and more accurately colors generally appear. CRI differences among lamps are not usually visible to the eye unless the difference is more than 3-5 points.

Color Temperature (Kelvin)

An expression of the hue of the light emitted, measured in degrees Kelvin. Usually expressed by a four digit number followed by (k), such as 2700k. Higher temperatures indicate whiter, "cooler" colors, while lower temperatures indicate yellower, "warmer" colors. Some common Kelvin temperature benchmarks are 2700k (warm white), 3500k (neutral white), 4100k (cool white), 5000k (bright white), and 6500k (daylight).
Color Temperature (Kelvin)

Brightness (Lumens)

A rating of the initial light output of a bulb, rated after 100 hrs of operation. Lumens are a measure of how much light falls on one square foot of area, one foot away from the light source.
Brightness (Lumens)

Bulb Finish

The surface finish of a bulb, which may affect the quality of the light emitted.
Bulb Finish

Bulb Technology

The technology implemented by the bulb, e.g. incandescent, halogen, LED
Bulb Technology

Average Rated Life (hr)

A measurement of the average length of time, between first use and the point when 50% of the lamps tested have stopped functioning, , using an operating cycle of 3 hours on, 20 minutes off.
Average Rated Life (hr)

Operating Temperature (°F)

The ambient temperature in which the product can safely operate.
Operating Temperature (°F)
-20 to 120

Beam Angle (°)

The width of a light beam, expressed in degrees. The beam angle is often part of the ordering code for reflector lamps. For example, a 50PAR30/HIR/NFL25 is a 50-watt PAR30 narrow flood lamp with a beam angle of 25 degrees.
Beam Angle (°)

Bulb Power Type

Defines how a lamp is powered, whether it needs a ballast or not, or can use either
Bulb Power Type
Ballast Bypass

Length (in)

Also referred to as "Maximum Overall Length" (MOL). For light bulbs, it measures the length of a light bulb, from the top of the bulb to the bottom of the base or pins and is typically expressed in inches. For light fixtures and ballasts, it applies to the total horizontal length of the item.
Length (in)

Diameter (in)

Light bulbs: a measurement of a bulb's width taken at the widest point of the bulb. Fixtures: the measurement across the widest point of a circular fixture.
Diameter (in)

Socket Type

Type of socket a linear lamp is compatible with, whether shunted, non-shunted or both.
Socket Type
Shunted or Non Shunted


5 year limited

Damp Location

Suitable for an exterior or interior location that is subject to condensation of moisture in, on or adjacent to electrical equipment
Damp Location

Rated for Fully Enclosed Fixtures

Not all LED bulbs are suitable for use in enclosed fixtures, due to the amount of heat they generate. Rated bulbs have been tested and approved as safe for enclosed fixtures.
Rated for Fully Enclosed Fixtures

Battery Backup

Has a backup battery to allow it to continue functioning in case of power failure.
Battery Backup
Customer Reviews
Q & A
I removed the ballast from the fixture, wired it as hot to one side and neutral to the other side. but when I installed the lamp it did not come on. The circuit was a constant hot not switched. but when I removed the lamp the emergency light did work it lit the lamp. what am I doing wrong?​


Hi Debbie, The power may need to be turned off to the fixture, then back on again (please see the wiring diagram at: If the bulb still isn't working correctly, please reach out to us at 888-455-2800, option 4 and one of our reps can assist you further.


The lamp says Before installation turn power off. What happens if power is on?


This can cause the bulb to malfunction, become defective and can create a safety issue.


I could use a wiring diagram.




Would the battery turn on the light every time you turn of the switch to the fixture? OR is it like the Sengled bulbs which sense if it is a switch you've turned off or the power itself has gone out?


The battery back up will only work when full power has been cut. This bulb will not light just because the switch was turned off.