About fluorescent tube replacement

It's a fuse to avoid the situation that someone misguidedly rewires the fitting with LN supplied at one end[1], and then installs the LED lamp reversed, which will (without the fuse, but a dead short) cause a short to the property electrics.

Yes, I understand why it is a fuse.

But they hide that fact and charge a lot for the trivial device.

And I'm guessing that perhaps, the other end of the tube, has a short circuit. Wait, I'm going to verify it [...] yes, that is so.

What you do will depend on how many fluorescent lamps and ballasts that you're talking about.

There are many options and if you attack the issue piece-meal, you're going to find that the market and the products available are shifting - probably faster than the decisions you make each time the problem of replacement parts arises.

Plug-in replacements are available. Some even have end-user colour temperature adjustments.There's no guarantee that these have any kind of demonstrated service life, or will be available in the market on a long-term basis, regardless of brand name.

This goes the same for anything requiring rewiring, but, if you do rewire, be sure that what you end up with doesn't need a working fluorescent ballast. That would be crazy. Even insisting on the T8, T10 or other pin compatibility, is probably a stretch.

LED 'ballasts' are supplied built into the replaceable element, resulting in a safety-certified straight mains input. Considering their poor demonstrated life performance, this will continue to be industry practice, for low volume installations.

You can get cheap ETL certified 4 foot LED lamp assemblies that have their own mounting hardware and versatile mains-compatible connectors out of SE Asia (where all the fluorescent hardware already originates, anyways).

I refitted a new storage area (series string of 4 x 4ft elements) with this kind of thing for less than the cost of one replacement fluorescent ballast.Two mechanical clips per element (single screw each clip), allowing easy replacement. 'Barrina'

Couldn't guarantee they'd still be available in the next few years, so I bought spares. . . . . Is the threat of lousy reliability just a trick employed by fly-by-night mfring operations to increase initial sales, before closing down?

RL

Just the one. And I expect to move house within a year, thus I did not want to rewire.

Expensive tube, though, charged as much for the tube as for the transport. I had to accept it, as I could not find that size locally.

It is impossible to find true fluorescent tubes here, unless you stocked them privately. Shops are prohibited from selling them, manufacturing also prohibited.

Maybe LED replacement for fluorescent tubes can be expected to be sold for many years, similarly to bulbs. There are trillions installed already.

I recently saw a shop front that was using replacement tubes to light their luminous signage. And it was new. They simply cabled one end of each tube; no reactance nor starter, so not M tube type. I didn't take a photo.

-----------== == N | |

-----------== == | | *----------------//-------------------------*

They used this

I just took the photo:

Applying power to one end of those tubes make the other ends live, (and hazardous). That's how they maintain physical reversability. I don't see any kind of covering on those exposed ends.

There isn't much leeway in the actual employment of replacement tube LED assemblies, to maintain public safety. Inlets, outlets, wiring, ground bonding and terminal splices/connectors are all still pretty well specified.

They should have kept the old mounting hardware, rewired it to fit their new tubes and labelled it for the next guy who comes along.

Use as directed. All these tubes come with full instructions for use and restrictive warnings.

RL

No, at least here. The other end in M tubes is just a short. Reversability is achieved by the (old) housing.

L N | | *-----------* | | *-------------| reactance |----* *--------------------* | *-----------* | | | | *----------------//-------------------------* | | | | | *-------==-- *-==---* | electronics | | *-------==-- M type tube *-==---* | | | | | *----------------//-------------------------* | | | *------------------(/)------------------------------------* starter

The type used in the photo is, AFAIK, not reversable. The active side, that houses the electronics, is marked with an aluminum foil label that wraps the tube circumference. The other end only does mechanical support, and is not wired. To be reversable, the housing on both ends has to be wired.

N *-----------------------------*---------------------------------* | | | *-------------------------------*------------------------* | | | L | | | | | | | | *----------------//-------------------------* | | | | | | | | | *------==-- ==---* | | | electronics | | *---------==-- ==-------* | | *----------------//-------------------------*

But I don't have one such tube to confirm it. The other possibility is:

N *-----------------------------* | | *-------------------------------* | | L | | | | *----------------//-------------------------* | | | | | *------==------------------···----------------------== | | electronics | *---------==------------------···----------------------== | | *----------------//-------------------------*

But those two internal wires might be seen from outside.

That's what they did on the photo. They removed the coil (you can see the board is blackened where it was) and the starter, then rewired only one end, kept the other for support, without any wire. You can see that they place the tubes carefully with the label side on the wired side.

I have seen this method used here often in shop front lights.

I don't think it's possible to determine the original contents of the pictured light box. I'm guessing it originally housed 4 or 8 tubes of identical size supported by conventional two-pin twist-lock end terminations, powered through 4 ballasts.

What's there now is completely jury-rigged. As most LED variants do not use evacuated glass tubing, or mercury, concerns for their mechanical protection may eventually be relaxed, but it's still mains wiring and must be treated as such.

I've bought and disassembled a variety of LED fluorescent substitute tubes. Those with L/N (ballast-free) end terminals complete the reversible connection on their internal LED printed wiring, or in one case, free wiring running behind the emmitter board for the length of the tube ~ your last drawing.

I've run across one non-reversible variety (though all 4 pins are still present for mech compatibility) with ends labelled 'A' and 'B' that had specific wiring instructions on each tube's label. You had to mark their housing appropriately with the same marks. I can't see that type ever being accepted in volume, by the industry.

The duplication of the T-type packaging is simply to allow retrofit into hardware that is already in service.

Those Barrina types I referred to were self supporting, with integral safe 3-wire mains socketry at both ends (comes with), for serially powered strings. You don't need the old hardware, but I suppose their mounting clips could be screwed into old boxes.

Some types are so poorly diffused that they are practically useless outside of a box that provided diffusing screen layers below the display advertising surface.

Prefab panels will employ basic light strips and a separate ballast to produce the DC voltage and current levels required for the configuration. Above 42V, these are still considered a potential hazard.

Internal ballasts for fluorescent replacements will typically output ~43 or 65VDC, depending on tube length, at 50-150mA.

RL

The photo looks terrible. Worse, I don't really understand what I'm seeing in the photo. Offhand, it looks like a pair of two different lengths cobbled together. The T8 designation is for the width of the tube (and not for the length). The length is determined by the wattage of the lamp(s).

"T4/ T5/T8 Fluorescent Tube Sizing Guide & Product Selector"

What was the original length of the florescent tubes? How many tubes were in the original fluorescent lighting fixture? How many watts did each fluorescent tube consume?

It should be possible to find a combination of LED tubes that with fit and work.

Disclaimer: I'm not an electrician.

To "legg". Thanks for the detailed explanations. I'm (slowly) learning from them.

It is a contraption I saw on the street. On top of that they put a plastic sheet with lettering, name of the shop or such.

Yes, they combine tubes of different tube lengths, and as they will be hidden, they don't need to be aligned.

I'm not sure if they are disassembling the old one, or reusing the base to create a new one.

The T8 I mentioned was for a different luminary in my bathroom. Originally 45 cm long from pin end to pin end, 15W.

Mazda TFP 15W LJ/54 Made in Holland.

replaced with a

LED tube T8 EM V

In the lettering luminaries that I have seen over time, they don't use two-pin twist-lock end terminations, but those screw things. The height is much lower and they need that. Very easy to install and much cheaper. At least in this country :-)

And 230 V ac over here.

DC? I don't think I have seen them myself, but I'm not an installer.

Overlapping fluorescent tubes behind a plastic diffuser is going to look awful. At best, there will be a hot spot where the tubes overlap. I don't think anyone knows what they were planning, including those doing the work. Do you have electrical wiring codes, permits and inspections in Spain? "Understanding Electricity Installation and Replacement in Spain"

Sorry, I didn't notice that when I first read the thread. I may have caused the problem by my habit of reading the thread from the latest to the earliest articles. Not having to repeatedly having to read quoted text saves me quite a bit of time and effort. In the future, I'll be more careful and also try to read between the lines.

There are inspection for the building. A lamp is "extra", not part of the installation. :-P

If you look carefully, the part that is overlapping is where the metallized label of the tubes are. Non light emitting just there.

The cookie banner of that site doesn't go out when I accept all cookies. Had to reload to clear the banner.

Something the site does not say: the initial installation doesn't need to be done by a certified electrician. But you have to obtain the certificate later from a licensed one before the utility will connect you. And it may happen that there is only one such in a big city. Once certified, the house doesn't ever need to be recertified, no more inspections. Business sites may be different, I don't know.

My house, for instance, is not certified. No issue from the insurer.