# Trouble with master/slave fluorescent fixture comfoguration



## iceman4160 (Jun 25, 2013)

Has anybody come across problems with master/slave fluorescent fixtures with electronic ballasts. We have about 400 2x4 fixtures with electronic ballasts the configuration is 2 ballasts in the master one ballast is a 4 lamp ballast serving the two outboard lamps in the master and slave and one 2 lamp ballast serving the inboard lamps in the master and slave, our problem is the outboard lamps are either not coming up to full brightness or not starting all together unless the power is removed from the 4 lamp ballast and then re-energized, kind of like rebooting or resetting.


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## DERITM (Apr 8, 2009)

Yes we had exactly this problem with "cow and calf" fixtures a couple of years ago while refitting a school. Three things we learned:
1. Problem usually occurs when using reduced wattage lamps (25w). 
2. Ballast revisions should be heeded. Ballasts of the same part number also have revision letters, A,B,C,D etc. Use the latest revision. Usually these have 750 volts open circuit as opposed to the 600 or so on older revisions.
3.Make sure that the tombstones are jumpered. The 25W lamps do not have a traditional filament and it seems to help to have both sides of the foil electrode connected to supply a good pulse. Also helps with lamp life.
You may also use 28W lamps in these hard starting fixtures and the problem goes away. 
We tore our hair out researching this but eventually got them all working
while learning the tricks. Hope this helps.


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## iceman4160 (Jun 25, 2013)

These have 32 watt lamps the lamps and the ballasts are from the same manufacturer, and these are new fixtures f


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## MaxH (Mar 12, 2014)

You have to make sure that tombstones are jumpered...Try it yourself otherwise don't take risk in electrical things...better take help...


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## iceman4160 (Jun 25, 2013)

MaxH said:


> You have to make sure that tombstones are jumpered...Try it yourself otherwise don't take risk in electrical things...better take help...



I am an licensed electrician and WTF are tombstones, are you talking about the pin sockets, they are jumpered everything is correct from the factory, it ended up a capacitance was building up in the slave wiring from the factory.


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## bml215 (Jul 2, 2012)

What is a master/slave set up?


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## iceman4160 (Jun 25, 2013)

bml215 said:


> What is a master/slave set up?


A master/slave configuration is two 3 lamp fluorescent fixtures where the master contains two ballasts , one is a four lamp ballast and the other is a two lamp ballast and the slave has a whip wired from the master controlling the two outside lamps and the inside lamp, this configuration is commonly used in higher end buildings, in this case it is being used in a sporting goods store with about 800 2x4 troffers


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## bml215 (Jul 2, 2012)

iceman4160 said:


> A master/slave configuration is two 3 lamp fluorescent fixtures where the master contains two ballasts , one is a four lamp ballast and the other is a two lamp ballast and the slave has a whip wired from the master controlling the two outside lamps and the inside lamp, this configuration is commonly used in higher end buildings, in this case it is being used in a sporting goods store with about 800 2x4 troffers


So the two lamp ballast controls the 2 outter lamps on the slave and the inner of the master, or the two lamp ballast controls all 3 lamps of the slave?


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## iceman4160 (Jun 25, 2013)

No, the two lamp ballast controls the inner lamps of the master and slave and the four lamp ballast controls the outer lamps of the master and slave


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## bml215 (Jul 2, 2012)

iceman4160 said:


> No, the two lamp ballast controls the inner lamps of the master and slave and the four lamp ballast controls the outer lamps of the master and slave


Gotcha, thanks


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## AllWIRES (Apr 10, 2014)

iceman4160 said:


> I am an licensed electrician and WTF are tombstones...


Hmmm


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