Underlamping a ballast?

[nadprosper]

Is it possible to have a ballast go bad due to using lower wattage bulbs than are speced on the ballast itself.....i.e.....2 f17 t8's on a ballast ( electronic ) whose lowest rated bulbs are supposed to be 2 f28 t8's.....if so, why. thanx

 

[robbietan]

as I understand it, ballasts are there to limit currents passing through the lamp so that the lamp would not blow. logically (I'm a Spock fan) the lower lamp watt would not be affected. a higher lamp could either render the ballast useless or will not work at all

 

[mxslick]

On the other hand...

On the other hand...

as I understand it, ballasts are there to limit currents passing through the lamp so that the lamp would not blow. logically (I'm a Spock fan) the lower lamp watt would not be affected. a higher lamp could either render the ballast useless or will not work at all

You're likely to have either a ballast failure or a remote possibility of violent failure of the lamp itself! As said in the first sentence of the quote above, ballasts limit current flow to the lamp (and provide proper starting conditions). So logically the lower wattage lamp WILL be affected..by overcurrent!!

Simply put, if the wattage isn't listed on the ballast, don't try it at home!! (Or work.)