Re: flickering fluorescents
T12 fixtures generally use a magnetic ballast whereas T8 fixtures use an electronic ballast.
Originally Posted by iceman11
The design and constuction of the T8 provides 3 to 10 % more luminens per watt and combined with the electronic ballast makes them more efficient than T12 with magnetic ballast.
Using T8 in a T12 fixture using magnetic ballast may work but it's hit and miss depending on the condition of the ballast and type --- pre-heat , rapid start , instant start. However the life of the T8 lamp and the old magnetic ballast will be shortened.
The information you provided regarding what the maintenace guy told you is partially correct but incomplete.
The T8 electronic ballast only supply one wire connected to each tube base socket unlike the T12 ballast which supplies two wires per base socket.
What the maintenace guy was describing is a method of converting your T12 fixture over to T8 -- which is easier than replacing the entire fixture.
Remove the old magnetic T12 ballast --- install a T8 electronic ballast --- at each existing base socket join the two wires together and conect to the single wire from the new ballast.
"" an ounce of perception -- a pound of obscure "