Wiring a replacement fluorescent light.

[giddyup]

Have a fluoro tube ceiling light in the laundry that started flickering, so replaced the tube then the starter, still flickering. So can only assume it's the ballast, so bought a whole new fitting, everything included. Problem is the old fitting has two wires coming down from the ceiling to the old light, black and grey, whereas the new fitting has a connection that has two wires, blue and red. Which way should the wires from the ceiling connect?

[giddyup]

  On 7/27/2019 at 3:57 PM, Arjen said:

It does not matter much. Black is usual live, while white or grey is neutral. I assume that on your new lamp the red wire is live. The live wire is the wire what is supposed to go direct to the ballast. To find out witch wire is the live wire from your connection in the ceiling you wil need a kind of measurement device (neon screwdriver for example)

 

Arjen.

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Something I don't have.

[Thainesss]

  On 7/27/2019 at 10:43 PM, giddyup said:

Something I don't have.

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Look at the old fixture and see which wire coming out of your ceiling went directly to the ballast, take that same wire and run it to the ballast wire on the new fixture. 

[Crossy]

In reality it matters not although as Arjen notes the black from the ceiling is (probably) live ansd should go to the ballast (probably the red in the fitting). It will work fine either way round.

 

[CharlieH]

Should've replaced with l.e.d plate, lower running cost no more flickering issues EVER !

[Thainesss]

  On 7/27/2019 at 11:09 PM, Crossy said:

In reality it matters not although as Arjen notes the black from the ceiling is (probably) live ansd should go to the ballast (probably the red in the fitting). It will work fine either way round.

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Ive ran into this issue before where I wanted to know/confirm which wire was live and which one was neutral. 

I have a cheap pen type voltage detector but that isn't really safe. 

 

I also have a DVOM. 

 

Whats a safe way to do that?

[Crossy]

  On 7/27/2019 at 11:13 PM, Thainesss said:

Whats a safe way to do that?

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Non-contact voltage detectors are fairly cheap and reasonably readily available. But of course they need batteries and batteries can fail, so before checking the wire that you want to verify you need to check the tester on a known live wire.

 

The neon testers are frowned upon by many professionals but if of decent quality and looked after (don't drop it in a bucket of water) they are pretty safe and very convenient, you really still need to check the tester.

 

I do own a non-contact tester, but it's invariably easier to grab the neon. I do admit to a very gentle flash with the finger on the end to start with when checking the tester. 

 

If you have an earth in the fitting you can use your DVM to find the wire with 220V to the earth.

 

[Thainesss]

  On 7/27/2019 at 11:23 PM, Crossy said:

Non-contact voltage detectors are fairly cheap and reasonably readily available. But of course they need batteries and batteries can fail, so before checking the wire that you want to verify you need to check the tester on a known live wire.

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This is the one I have, its just a cheap, locally purchased one. And the wire im testing needs to be hot to check, which has caused me problems (sort-of) because if its around other hot wires in a run the result isn't as "positive" as I would like because it seems to pick up bleed off from other wires. Are more expensive units like a Fluke brand unit more "positive" of a tester? 

 

  On 7/27/2019 at 11:23 PM, Crossy said:

The neon testers are frowned upon by many professionals but if of decent quality and looked after (don't drop it in a bucket of water) they are pretty safe and very convenient, you really still need to check the tester.

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Talking about the one with the little bulb that uses your body as earth right? 

 

  On 7/27/2019 at 11:23 PM, Crossy said:

If you have an earth in the fitting you can use your DVM to find the wire with 220V to the earth.

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This is exactly what I do when theres an earth wire in the area, but even then half the time earth isn't even hooked up correctly and doesn't work. Ive never ran into this issue in the states because every receptacle is bonded and I can just test 220/110 to earth and get a hard confirmation. 

[Crossy]

  On 7/27/2019 at 11:44 PM, Thainesss said:

Talking about the one with the little bulb that uses your body as earth right? 

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Yup, the current is tiny and usually below the limits of perception.

 

Nothing to stop you running a wire from the finger cap to something earthy, it can be a really crumby earth (like your aluminim step ladder ).

 

[jastheace]

  On 7/27/2019 at 10:43 PM, giddyup said:

Something I don't have.

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50 baht from big c

 

[jastheace]

  On 7/27/2019 at 11:51 PM, Crossy said:

 

Yup, the current is tiny and usually below the limits of perception.

 

Nothing to stop you running a wire from the finger cap to something earthy, it can be a really crumby earth (like your aluminim step ladder ).

 

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runs through a 220k resistor, if neon faulty won't kill you but you'll know its hot/ live

 

[bankruatsteve]

There's a barefoot method to determine "live" with a DVM that I use and couldn't be any less safe than a neon screwdriver but, for whatever reason, it is frowned on by the TV mods.

[Thainesss]

  On 7/28/2019 at 12:58 AM, bankruatsteve said:

There's a barefoot method to determine "live" with a DVM that I use and couldn't be any less safe than a neon screwdriver but, for whatever reason, it is frowned on by the TV mods.

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Go on. I mean the Neon screwdriver is generally considered as ridiculously unsafe, and Id like to know of a positive confirmation type DVOM method. 

This was more or less what I was trying to ask.

 

????

[bankruatsteve]

  On 7/28/2019 at 1:08 AM, Thainesss said:

 

Go on. I mean the Neon screwdriver is generally considered as ridiculously unsafe, and Id like to know of a positive confirmation type DVOM method. 

This was more or less what I was trying to ask.

 

????

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PM sent.

[Thainesss]

  On 7/28/2019 at 1:17 AM, bankruatsteve said:

PM sent.

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Received. 

 

Gotta admit Im feeling a bit vindicated and less juvenile for asking such a question. 

 

Sorry @giddyup for the hijack. 

[giddyup]

I installed the new fitting, turned on the light, still flickering, removed the starter, light works perfectly. What's going on?

[giddyup]

Just worked it out. I'd mistakenly bought a LED spare globe, obviously doesn't need a starter, but it does have a dark line running the length of the globe for some reason.

[Curt1591]

  On 7/27/2019 at 11:10 PM, CharlieH said:

Should've replaced with l.e.d plate, lower running cost no more flickering issues EVER !

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Best thing I ever did!

[Crossy]

  On 7/28/2019 at 2:50 AM, giddyup said:

Just worked it out. I'd mistakenly bought a LED spare globe, obviously doesn't need a starter, but it does have a dark line running the length of the globe for some reason.

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Turn it 180^o in the fitting so the line is away from the glass ????

 

[giddyup]

The whole thing was a comedy of errors and what turned out to be totally unnecessary work and expense, minor admittedly.

 

1) Assumed the flickering was caused by faulty tube (tube was dark at the ends)

2) Bought a new tube but flickering still there. This is where I made the major mistake.

3) Assumed flickering was a faulty starter, replaced starter but flickering persisted.

4) Bought a whole new fitting as now assumed it was the ballast. Flickering still persisted until I removed starter, then fine.

 

If I'd realised that I'd actually bought an LED tube instead of a normal fluorescent tube all that would have been necessary would have been to replace the correct tube. Oh well, live and learn.

[Crossy]

  On 7/28/2019 at 7:03 AM, giddyup said:

If I'd realised that I'd actually bought an LED tube instead of a normal fluorescent tube all that would have been necessary would have been to replace the correct tube. Oh well, live and learn.

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But you will have accidentally reduced your power bill slightly. 

 

Cannot be bad, I've had some rather more expensive mistakes