Choosing LED Tube lights

Fluorescent ballasts and LED tube light retrofitting

All fluorescent tube lights use a device called a ballast to regulate the lamp’s brightness as it warms up. These devices are necessary for fluorescent lamps, and differ from incandescent lamps which can be connected directly to mains electrical circuits.

Fluorescent lamp fixtures typically house the ballast inside the fixture, and is not accessible without removing the fixture from the ceiling. Alterations to the fluorescent lamp ballast should be done only by those comfortable and knowledgeable with electrical work.

T5, T8 and T12 fluorescent lamps operate slightly differently, and therefore have different fluorescent ballast types.

LED lamps, on the other hand, operate differently from fluorescent lamps, and do not utilize a ballast (but do utilize electronic components that make up the LED driver).

Early LED tube lights required removing or bypassing the fluorescent ballast. Now, many LED tube lights are designed to be compatible with fluorescent ballasts, allowing for a simple replacement of the fluorescent tube, without re-wiring the fixture. Below, we discuss the common terms used for each of these configurations.

Typical Fluorescent Tube wiring

What is the difference between a single and double ended LED Tube?

The difference between single and double ended LED tube wiring is shown below.  In both instances, it maybe possible to keep the current wiring in place when converting to LED tube.  For a single ended tube installation, this will mean removing the fluorescent starter and simply putting in the new single ended fluorescent tube.  For a double ended LED tubes, like Philips Corepro, for example, the fluorescent starter will need to be removed and replaced with the new LED started included with each tube. The LED starter acts as a bridge wire using the old fluorescent starter wiring to re-direct the neutral power supply to the same end of the tube as the live supply as indicated below.

Some web pages talk about ‘UL Approved’

What does UL Approved mean? This is an American Term not usually used in Europe

There is no such thing as “UL Approved.” UL (Underwriters Laboratories) has “UL Certified” and “UL Listed” as marks. A fixture may be UL Certified, but a component like a ballast or an LED tube will be UL Listed. UL is primarily concerned with safety requirements. UL listing is unconcerned about long-term product performance or any kind of life testing. 

All LED tubes are listed as UL Type A, Type B or Type C. Type A operates on fluorescent ballasts, Type B is direct wired to the mains with the ballast or driver being located inside the tube and can be a single or double ended tube, and Type C operates on its own dedicated external LED driver. 

More on Type A, Type B and Type C LED tubes as below.

Type A LED tube light – Ballast Compatible

Commonly designed “Type A” – these LED tube lights are designed to be compatible with fluorescent ballasts. They are the most straightforward to implement, since it does not require rewiring the fluorescent fixture.  The Type A LED tube light essentially behaves the same a fluorescent lamp, and is a straightforward swap-in.

Type A LED tubes can be single-ended or double ended.

Ideal for: Consumers not comfortable with or preferring to avoid electrical wiring work, lighting installations where electrician labor costs are high

Disadvantages: Fluorescent ballasts can fail, requiring continued maintenance and eventual replacement or bypass of the ballast; potential issues with fluorescent ballast compatibility; lower overall electrical efficiency due to ballast.

Type B LED tube light – Ballast Bypass

LED tube lights that have a “Type B” specification may not be fully compatible with fluorescent ballasts. They cannot be used with the fluorescent ballast, and must be connected directly to mains electricity. The LED driver, however, is integrated into the LED tube itself.

Type B LED tubes can be single-ended or double ended.

For single-ended configurations, the direction in which a lamp is installed is important – incorrect configurations can lead to a lamp that does not illuminate, or a potentially hazardous fire risk. Single-ended configurations will typically have a sticker label on one end of the tube with the words “AC INPUT” or similar. Some single-ended configurations can accept power from either end.

In a double-ended configuration, the two pins on each side of the tube are the same polarity. Therefore, the lampholders on one end of the tube must be connected to [neutral], while the other must be connected to [positive].

Ideal for: installations where electrical rewiring is an option; higher efficiency and lower maintenance costs.

Disadvantages: requires comfort with and and knowledge of fixture wiring and electrical safety.

Type C LED tube light – Remote Driver

Type C LED tubes are relatively uncommon, but offer the most flexibility and efficiency for a lighting system. Unlike a Type B LED tube, these do not have the LED driver integrated into the LED tube, and therefore requires a separate LED driver device to be connected between the LED tube and mains electricity.

Ideal for: lowest maintenance costs as LED drivers can be replaced without replacing the whole LED tube; more LED driver options such as 0-10V dimming and other IoT connectivity.

Disadvantages: Requires the most electrical work as the fluorescent ballast needs to be removed, then replaced with an LED driver.

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