Retrofit LED 5ft tubes in existing fittings query.

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Evans Electric

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Just done one to see how they look before ordering another ten .    

Following the instructions  I removed the capacitor , inserted two  LED starter switches and they work OK  .

Just can't see why the ballast   ( or CCG as they call it :C ) is left in the circuit  ...anyone one know why ....is there any power saving with that still in circuit ? 

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If there is any saving it can only be by power factor correction.

The current through the ballast is much less than its original design level, but there will still be some iron losses, and some minor volt drop across it.

On the other hand the LED tube probably has capacitive ballasting, so perhaps by leaving the ballast in, (now a series L/C circuit), its better than  not having the inductance in circuit from a power factor point of view?

In practice I suspect the main purpose of leaving the ballast in is just to simplify the installation process.

The instructions for converting electronic ballast fittings indicate that the tube can take full mains voltage, so the ballast is definitely redundant from that aspect.

 
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Why remove the capacitor from the existing fitting? I did one and left the cap in.

TIP:  do NOT try an LED "tube" in a fitting with electronic ballast.  The person I know that tried it did get his money back when he returned it as "faulty"

 
I've done loads of conversions, with Crompton tubes (really like these) and always re-wire the fitting to remove the ballast and capacitor - easy to do, 240V straight to 1 end cap. This maximises the energy savings (an energised ballast will use some electric) and also avoids the potential to cause a fire. Plastic tube lamps I have seen burnt-out when not doing the above. HF ballasts are the apparent cause of said fires, but to do anything less than the full 240V conversion is just plain lazy to me (takes me about 5 mins, 10 if deprived of tea for an hour or more  :^O ). 

 
Well  as I often read on here , I'm following the manufacturer's instructions ....remove the capacitor ...leave the choke in circuit .

As said , probably to minimise rewiring ,  I note that the pins at the "dead" end of the tube  are shorted out , which saves an alteration .   

I put a call into Crompton  to ask about the ballast  ,  they never phoned back  but I will pursue  that  .     There are more to do  so I want it right . 

 
You can do it that way, it's not a problem, but I prefer my method as I have found it to be totally reliable - if you leave an old ballst in the cct, how long until it fails???  It's so easy to open up the fitting, and cut a few of the wires running to one end cap, disconnect feeds to the ballast, then wire end cap straight to the connector block. No need to remove ballast.

 
- if you leave an old ballst in the cct, how long until it fails??? 
My thoughts exactly  ....I find it most strange TBH  .     

Edit:-       OK  I have just spoken to Crompton  who advise me to take the ballast out of the circuit ,  contrary to what their leaflet says   :C

 
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Perhaps you could suggest that they take their lead from the IET and issue and amendment to their instructions, obviously explain that they can have up to three amendments before a whole new set of instructions is written 🤔

 
I phoned them  again today as the tinternet  could not explain exactly  what  the LED starter does & whats inside it .       Told it was just a link .   Picked up my order of tubes  this afternoon , pulled  a starter apart  to find its a fuse .   

So recapping ....ballast & capacitor OUT  ... alter wiring  to give a neutral to the end cap   (Or tombstone)  and a live through the  old starter base  with an LED canister in it .  

 
I phoned them  again today as the tinternet  could not explain exactly  what  the LED starter does & whats inside it .       


You will be getting a reputation on their customer support desk, with whispered messages between call centre staff, "Watch out for that nutter who keeps phoning about LED tubes"! "If he phones again to ask the Kelvin rating of each tube just tell its plenty"!

Doc H.

 
So recapping ....ballast & capacitor OUT  ... alter wiring  to give a neutral to the end cap   (Or tombstone)  and a live through the  old starter base  with an LED canister in it .  
 Nope, each end cap has 2 terminals and therefore 2 cables, make one Line, the other Neutral, polarity is not an issue. Just remember which end you did this as the tube has a driver one end (end with label) which needs to go to the altered end cap. Don't need the LED fuse - you could wire it with that in if you wish, but I never have. Installation method B on the sheet, at the bottom.

 
Nope, each end cap has 2 terminals and therefore 2 cables, make one Line, the other Neutral, polarity is not an issue.
  When you say nope  do you  mean yep                 I'm sure  I just said  a N & L at the end cap  ;)  

Been back there today  corrected the first one  , (so  not complying with Manufacturers  Instructions )    and  converted another 10  .  ( Also not complying )    

Sidewinder would have a heart attack .        

Don't need the LED fuse -
Why do they supply a fuse  ?

 
I know what Sidey would say ..............   as you stand up in court after the fire the judge says  " Did you  follow the MI's  attached to these light fittings ?  

"  No M'lud  I decided they were wrong and connected them my way "  

" And are you a light fitting manufacturer ?"

" No M'lud " 

" Did you fit the fuse supplied by the manufacturer ?  

" No M'lud I threw it away " 

"  Are you an expert in installing retrofit LED tubes ?"

" No M'lud" 

"  Send him down !!!"

 
Why do they supply a fuse  ?
 Nope means no, you were on about going via old starter base, which you don't need to. As for the fuse, I've no idea, but think that is just for semi-converted fittings where people can't be arsed to re-cable anything, so starter comes out, and fuse link goes in its place.

You missed your defence Deke:

well m’lud, I frequent a professional forum and the member known as Binky is the resident retrofit Led tube expert. 


It complies with the manufacturers instructions - Crompton told me to do it!!! To date I have retrofitted hundreds LED tubes, with no issues at all, unlike some that I have seen where a part conversion has been completed and fires have been caused.

 
- Crompton told me to do it!!!
What I should have done  was to email them  so I'd have an answer in writing .    Thats what Sidey would have done . 

I'm just happy the chokes are out of the circuit ....I fitted the fuses , can't see anything wrong with that . 

I suppose I could prove in the mythical court that the MI's were misleading by showing the chokes.   

Actually I just looked at the MI's above  and realised the fuse is in the neutral  ...the  "Dead" end of the tube  has the pins shorted out .....if  the fuse failed the lamp circuit would still be live .....  at least I have them in the live . 

 
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