On topic. LED tube replacements, double end vs single end

[TimR]

I have two more 2 foot fluorescents in the bathroom that need replacement. As bulbs or ballasts fail I'm converting everything to LED. These two have starters so they must have unshunted tombstones.

The first replacements I did were single end. You run power only to one end of the tube. The other tombstone becomes just a support. The last one surprised me, it was a double end, had to run power to both ends of it. But it needed shunted tombstones, or at least the installation instructions said to tie the wires together.

Any reason to prefer one over the other? Apparently I can get either one. If one goes bad though, will I still be able to get a replacement for that kind?

It seems likely to me that the double end ones probably use only of the end pins to connect, to ensure safety in case you put one in a light wired for single end. But I couldn't find any actual info on that. If you put a single end one in a double end light it wouldn't turn on but it wouldn't be a hazard.

[Marilyn Manson]

Does this help?

[TimR]

I read that one but I'm not sure I believe it.

I've done several conversions now, removing the ballast for disposal and rewiring, and I can't tell any difference in time between wiring single end or double end. So far I've always had unshunted lampholders to start with, but I think I may have swapped some out for new anyway for some reason. That 5 minute estimate is optimistic, I spend more than that looking at the wires and deciding where to cut and splice, drawing the circuit to be sure it's going to work, etc. Yeah, actual connection time isn't much. No two fixtures were wired exactly the same; the last one confused me until I figured out someone had disconnected the pull switch on the fixture but left everything there.

This particular fixture has combination starter/lampholder tombstones at one end of each tube. I'll have to replace that one if I go double end, swap ends if I don't. I'm thinking ahead to whoever comes after me - not so young anymore. And, what ifs. If my kids live there and a qualified electrician shows up to fix, probably no problem. A handyman could put a new fluorescent, a single end LED, or a double end LED in whatever I leave them. It seems possible that the double end is the safest for that problem.

[Marilyn Manson]

I did a few conversions on some 4' shop lights a few years ago, but most of the fixtures in the basement were so old, I just bought new chain-hung 4' LED shop lights instead of converting them. I also bought a few 3' hanging fixtures for smaller areas, like behind the furnace. If you pull the mounting chains tight enough, the fixtures are not really "hanging", meaning that they are tight against the joists. Some are hardwired, some are plugged into receptacles mounted to the ceiling joists. None of mine have replaceable tubes anymore.

Putting a receptacle on the end of the original Romex and using a corded shop light allowed me the freedom to relocate them without pulling new cable (in some cases). The original hardwired fixtures were switched, so the receptacle is now switched meaning no difference in operation.

The main ones for the basement are switch controlled by a single switch, and the others, in areas that are used infrequently, are pull chain.

When I first moved in, there were 6 individual pull chain porcelain fixtures spread out throughout the basement. The switch in the kitchen turned on the fixture at the bottom of the stairs. After that you had to pull chains as you walked through the basement. Pull them all on, pull them all off. A real pain when you are carrying stuff.

I almost immediately rewired the fixtures so that all of the pull chains were down stream of the switched one. The single switch controlled them all. Later, all 6 of the porcelain fixtures were replaced with three 4' fluorescents, which are now 4' LED fixtures. (The previous owner lived there for 30 years, with a family of 6, putting up with the individual pull chain fixtures. I lasted about a month before doing the really simple rewiring.)