Ceiling Light Bulb Replacement - Can't remove cover

[lt8480]

We have the light fitting shown in the attached in our hall. The bulb has started to flicker so wish to change. Assume it is a 2D bulb.

Cannot work out how to remove the cover.

The translucent cover pushes upwards. Doing so reveals 3 metal tabs that can be seen in the gap at equal spacing around the rim (between the metal frame and the cover - see second photo).

In the plastic cover there is a small 1cm wide notch. Assume this is so you can align the notch with the small cable feeding the green light (emergency light?) on the side when you push up the cover so you don't damage that cable. But maybe its to give access to the metal tabs?

The whole fitting also feels as if it pushes up to the ceiling but on one side only.

Any ideas how to get to the bulb?

 

[flameport]

The outer metal ring pulls off, which then allows the centre plastic part to be removed.

 

[lt8480]

In the end it appears to simply wrestle out by bending the diffuser part. Anyway got it off, swapped the bulb with a new 28W 2D 4 pin bulb, and still have the flickering.

I assume unlikely new bulb would have exactly same issue.

Photo attached of inner. Any thoughts what else could be wrong?

Could I simply put in a LED 2D 4 pin bulb to try and negate whatever the problem is?

 

[lt8480]

Looking at one of these to avoid replacing the whole light fitting or inners:

https://www.amazon.co.uk/LED-12-5W-...=2d+LED&qid=1555264444&s=lighting&sr=1-6&th=1

Someone has helpfully noted "the CCG variations work with wire wound chokes (old style), The ECG variations work with Electronic (High Frequency) control gear (new style)" ... however not sure what I have. ECG?

 

[JohnD]

The 2D bulbs are pretty old now. Maybe consider replacing with a new luminaire that takes an ordinary domestic LED lamp?

You mentioned a green light, which usually indicates a lamp that has an emergency standby supply that will illuminate in a power cut, and I see yours has a complicated power supply and a battery, which corresponds. The battery may have expired its life by now.

 

[lt8480]

Light fitting installed about 2.5 years ago. Has a 5 year warranty. Was also tested last year.

Whole building due to be gutted and rewired in 6 months time including new fittings. So looking for just a solution till then.

 

[333rocky333]

That fitting is an EMERGENCY light although it has a form of ECG, the Led lamps will not work with a combi unit.
ECG is Electronic Control Gear. CCG is Convential Control Gear, Ie when you have a Starter in circuit.

New rules have drove makers to do both ECG and CCG versions now, there trying to limit people doing bodged potentially dangerous conversions of existing fittings.

The flickering is caused when the combi unit (the square box thing) fails.
Is there a reason it needs to be an emergency light, if so then it needs replacing with a Maintained emergency light, that can be switched off and on like a normal light.
The batteries are dated 2010
https://www.amazon.co.uk/Emergency-...ergency+light&qid=1555282149&s=gateway&sr=8-5

 

[lt8480]

Thanks.

That fitting is an EMERGENCY light although it has a form of ECG, the Led lamps will not work with a combi unit.

It doesn't need to have a light or an emergency light in the location anymore so was hoping for a simple fix simply to stop the flickering as simple on the same circuit as another light.

May be best to simply remove the bulb and wait for the scheduled work in a few months when the light fitting due to be removed due to new lighting going in different locations.

I am curious from a technical point of view how the combi aspect stops it working. I always assumed the battery simply provided power in the event of a power cut but worked generally the same as a normal light?

 

[333rocky333]

Basically In a normal emergency light you would have 2 units, (1 is an inverter and 1 is a normal ballast), in normal use the fitting runs on mains via the ballast and works even with the battery disconnected,

Inside the inverter amongst other bits are 4 changeover relay switches, on mains failure these switch the 4 wires from the ballast to the lampholder, the lampholder wires then divert to the inverter guts, this then uses the battery power to supply the light from the inverter, hence its dimmer.

Other things also go on inside the inverter, usually when inverters die you hear them chattering.

With a combi all this (Inverter and Ballast) is crammed in 1 unit and as its mainly electronics it tends to fail completely or flicker erratically, sometimes powering it down cures it, but often short term.

In normal use the combi is still doing the work of a normal Electronic ballast, in mains failure its doing the work of an inverter, hence either part can fail.
You sometimes find the light still actually works on emergency mode, but is erratic like yours in normal mode

 

[Adam_151]

New rules have drove makers to do both ECG and CCG versions now, there trying to limit people doing bodged potentially dangerous conversions of existing fittings.

Do you have a link/reference for that please?

I do know of one manufacturer of LED conversion 2D lamps that does a pre-converted fitting with no control gear, just 240v onto the lamp socket, the emergecny version is quite good as well, with the emergency module that feeds into the separate connector on the lamp PCB. I was doubtfull of them at first, but I've fitted loads now and am quite impressed

 

[333rocky333]

Do you have a link/reference for that please?

I do know of one manufacturer of LED conversion 2D lamps that does a pre-converted fitting with no control gear, just 240v onto the lamp socket, the emergecny version is quite good as well, with the emergency module that feeds into the separate connector on the lamp PCB. I was doubtfull of them at first, but I've fitted loads now and am quite impressed

I read it a while back somewhere, some of it seems to be referred to here.
https://www.electricalsafetyfirst.org.uk/media/1206/best-practice-guide-9.pdf