Back when I started the trade most of Canada was still 25 cycle .
Well the first job I was on as an apprentice I new zip about many things .
I was working at a new building and every thing was 60 cycle and my job was to confirm nothing was 25 cycle going in .
We has a shipment of fluorescent fixtures and they where all 60 cycle .
In the next room was all the Tubes and they had big purple stamp on each box 25 cycle tubes .
I went to the forman and he was so glad I had caught this well they made arrangements to get the correct tubes and lots of phone calls and how where we going to get the proper tubes .
Now the question for all the electricians out there is what was the difference between 25 cycle and 60 cycle Fluorescent tubes .
Answer Sunday
The 25 Hz lamps have a slightly different blend of phosphor coating inside the lamp to try to lessen the visible flicker that comes from 25 Hz operation of fluorescent lamps. The idea is to keep them “glowing” longer between the cycles. Those lamps will still work fine on a 60 Hz system. These 25 Hz lamps are still made by GE for some 25 Hz lighting that still exists in small portions of the New York City subway system.
I do not know about the coating but you are correct about the flicker it is very no ticable on 25 cycle .
What they did was to put a 2 inch piece of white carboard tube ( very much like if you cut a toilet paper tube in half.) over the ends of the Glass tubes as this is where the flicker was most no ticable .
Good one Marc two Stars for you.
They almost shipped the 25 cycle tubes back to the factory to get the correct ones 60 cycle ones.
I wonder is India still 25 cycle I understand all the 25 cycle Alternators where shipped of shore .
Careless Roy
Roy Cooke
