2 x 9W PL Energy Saving Outdoor Bulkhead with Photocell

[pete100]

Hi,
I am about to buy this light unit (without the lamps) and I am wondering if it will be O.K. to fit 7W lamps instead of the 9W specified.
All help on this subject appreciated.

pete100

 

[ricicle]

Lamp life will be reduced if the control gear is not suitable for 7w lamps.

 

[ban-all-sheds]

Why?

 

[333rocky333]

With a single unit the same ballast usually does 7, 9 or 11 watt not to sure about the two lamp unit you want, but it is likely to be printed on the ballast or ballasts when you get it.

Would there be any point in using 7 rather than 9 if you want it less bright go for lower colour lamps.

The ballast limits current to the lamp, therefore the extra current supplied through from a magnetic choke slightly reduces the lamp life of a lower wattage lamp.
Though with the smaller wattage lamps it is negligable.

With H/f units it is similar but they usually cover a wider range including series wired twin lamps, again its printed on the ballasts.