T5 54w lamps pulse

[stevebea]

Situation is linear lighting in a retail space. Customer wanted to dim these lights so one of our guys installed Advance Mark 10 ballasts ( 2 wire dimming ballasts) and a Cooper AF10 dimmer. The dimmer is rated is rated 8.3A and actual load is 6.75A. The problem is the lights will occasionally pulse as in the lights will get brighter for a split second . It usually does this two or three times in quick succession and then settles down and may not do it for another 45 minutes. The only thing I found was that when the dimming ballasts were installed the sockets were never rewired so the sockets were in parallel ( shown on ballast ) instead of being in series. Could this be the root of the problem? The ballasts and dimmer are compatible according to both manufacturers. Any input ? Thanks.

 

[ActionDave]

I would say yes. I have never put dimming ballasts in existing lights but I have replaced them with normal ballasts and had to rewire the tombstones. Makes sense to have to do the same in an opposite way.

 

[LEO2854]

Situation is linear lighting in a retail space. Customer wanted to dim these lights so one of our guys installed Advance Mark 10 ballasts ( 2 wire dimming ballasts) and a Cooper AF10 dimmer. The dimmer is rated is rated 8.3A and actual load is 6.75A. The problem is the lights will occasionally pulse as in the lights will get brighter for a split second . It usually does this two or three times in quick succession and then settles down and may not do it for another 45 minutes. The only thing I found was that when the dimming ballasts were installed the sockets were never rewired so the sockets were in parallel ( shown on ballast ) instead of being in series. Could this be the root of the problem? The ballasts and dimmer are compatible according to both manufacturers. Any input ? Thanks.

Are there any adjustments on the dimmer switch?

 

[Electric-Light]

Situation is linear lighting in a retail space. Customer wanted to dim these lights so one of our guys installed Advance Mark 10 ballasts ( 2 wire dimming ballasts) and a Cooper AF10 dimmer. The dimmer is rated is rated 8.3A and actual load is 6.75A. The problem is the lights will occasionally pulse as in the lights will get brighter for a split second . It usually does this two or three times in quick succession and then settles down and may not do it for another 45 minutes. The only thing I found was that when the dimming ballasts were installed the sockets were never rewired so the sockets were in parallel ( shown on ballast ) instead of being in series. Could this be the root of the problem? The ballasts and dimmer are compatible according to both manufacturers. Any input ? Thanks.

According to the brochure, the T5 Mark X wires up just like the old school two lamp the old school F40T12. Wire according to the ballast label. Disregard everything else. Some dimmers, ballasts, or certain combinations are very sensitive to voltage flicker which may come from a water heater, refrigeration equipment and there's not much you can do. I would hook up a corded drill or something on the same branch circuit as the dimmer and repeatedly cycle the drill and watch if you can cause the lights to flicker. Some will produce very objectionable flicker with a sudden voltage change of just one percent. This is not part of official product specs. The ability of ballasts/dimmers/decorative light drivers to tolerate voltage flicker vary significantly between each model and even engineering revision models.

 

[stevebea]

Are there any adjustments on the dimmer switch?

There are no adjustments and this pulse will happen at any dimming level.

 

[stevebea]

According to the brochure, the T5 Mark X wires up just like the old school two lamp the old school F40T12. Wire according to the ballast label. Disregard everything else. Some dimmers, ballasts, or certain combinations are very sensitive to voltage flicker which may come from a water heater, refrigeration equipment and there's not much you can do. I would hook up a corded drill or something on the same branch circuit as the dimmer and repeatedly cycle the drill and watch if you can cause the lights to flicker. Some will produce very objectionable flicker with a sudden voltage change of just one percent. This is not part of official product specs. The ability of ballasts/dimmers/decorative light drivers to tolerate voltage flicker vary significantly between each model and even engineering revision models.

Thanks. I will give that a try. Start the A/C, run hot water so the stat on the water heater closes, anything I can do to cause some VD.

 

[Electric-Light]

Thanks. I will give that a try. Start the A/C, run hot water so the stat on the water heater closes, anything I can do to cause some VD.

A drill is a better test since you can hook it right into the lighting circuit (BEFORE the dimmer, NOT after) and observe if flicker follows. Flickers are difficult to diagnose. You're limited to the visual check or a power quality analyzer. From the values you provided, I'm guessing you're using a 1000VA 120v setup.

Most ballasts today will regulate light output right on the dot whether you give it 108v or 140v, but many don't respond fast enough to avoid a visible flicker on a sudden change as little as between 120 and 123v.