Incandescent lights

Jon Elson elson at
Fri Feb 6 23:25:57 CST 2015

On 02/06/2015 09:20 PM, Tothwolf wrote:
> These are single-ended-power type retrofit tubes, so a 
> rapid start ballast really shouldn't harm them (the two 
> pins on one end are not connected to the circuit). The 
> older double-ended-power type retrofit tubes are the ones 
> to be afraid of...they are a shock hazard (well 
> documented) if both ends of the tube aren't fully seated. 
> The double-ended-power types are also now banned in many 
> countries.
OK, good to know that they fixed THAT bit of insanity!
> Are you sure those tubes on Amazon require the ballast to 
> be removed? Many of these retrofit tubes do not, although 
> some require the starter circuit to be bypassed. [In the 
> US, with 4ft T12 and T8 fixtures, the starter circuit is 
> built into the ballast, but that convention isn't 
> universal, and in many countries fluorescent fixtures use 
> a separate starter module in a socket.]
I haven't seen anything except desk lamps that used a 
separate starter (or manual
button) in the last 30 years or so.
Our house was built in 1975 and the 4' fluorescent fixtures were
all rapid-start ballasts, meaning the starter is part of the 

Anyway, I'd sure WANT to remove the old ballasts, as they 
were massively
inefficient.  I measured one of the ones before I did the 
retrofit. Two 48"
tubes, total power draw 103 W.  Assuming the two tubes drew 
32 W each,
the ballast was drawing another 39 W or so!  I had to remove 
the ballast
with pliers, it was too hot to touch after a couple hours run.


More information about the cctalk mailing list