# Lutron Grafik Eye Question



## Dube2 (Apr 24, 2012)

So, a few weeks back I was on a job walk with my (know it all Boss) and we come to find while on site the client has an issue with their Grafic eye. one of the 20amp breakers was tripping. all the fixtures on that circuit we're running just fine. The Lutron panel is about 22 years old and in need of replacement. as a matter of fact we were there to give an estimate on replacemnt of the Lutron panel. Anyway, after I counted the 25 MR16 75watt fixtures and figured the circuit should not draw more than 15.6 amps under perfect conditions. well, once I finally got them to let me open the panel and take a peak, the circuit was drawing 21 amps plus. Anyway, I suggested to by-pass the module and install an external switch or slide dimmer till the panel can be replaced in a few weeks. My know it all boss says to install a 30amp breaker on a #12 wire and it should hold till then. I was not comfortable with that and asked if I can baypass it for 5 minutes and just rule out the Module, he declined and told me I was nuts. 

Not my first Rodeo Dude...:001_huh: anyway, I checked the voltage at it's current state and had 109volts. not an issue, but I still feel its the module. Two days later the 30amp breaker was tripping, so I sent my service tech to by-pass the module and do it my way this time. only took 10 minutes for him to call me back and confirm the module was overlaoding the circuit. the amperage was 15.? and holding. 5 days later and all is still good. Oh, we put the 20amp breaker back in the circuit. Stupid boss anyway.

My real question... Does the module not only adjust the voltage, but does it also adjust the cycles? Assuming I still had 109 volts, the cycles must have been going haywire on the resistance and causing overload condition. 

Your thoughts anybody???

PS: My "Know It All Boss" has not commented on this matter since that day...:laughing:


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## Dennis Alwon (May 9, 2009)

I would first of all question why you have 109V. That is much lower then it should be as it is 10% drop.


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## sbrn33 (Mar 15, 2007)

Your boss doesn't sound like the only know it all on that job.


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## Control Freak (Mar 8, 2008)

That post was like a book!


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## ScooterMcGavin (Jan 24, 2011)

If this is a GP dimming panel (and it sounds like it is) buying a new panel won't change anything other than getting you new cards. The actual dimming technology hasn't changed in those twenty years. The 109V, was that the line side or the load side of the dimming card. By default the dimming cards are set at a maximum of 90% so even when you are at 100% on the grafik eye you're still only putting out approx 90% of the voltage. the dimming level vs actual voltage isn't going to be one to one relationship because of the way your eyes perceive light levels.

The dimming cards don't change the cycles what they do do is "chop" the sine wave which lowers the voltage and brightness of the lamp. Did you try dimming the circuit to see how the current changes? It's possible there is a high resistance ground fault in the dimming card which could cause the overload as well. Having the load type setup wrong could also cause some trouble but if the system has been in service for many years and now is suddenly having problems I would suspect a bad card.


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## Dube2 (Apr 24, 2012)

hahaha, Guess I should have expected that...:laughing:



sbrn33 said:


> Your boss doesn't sound like the only know it all on that job.


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## Dube2 (Apr 24, 2012)

Yea, totally Scameron81. the primary voltage was normal at 120, the seconday from the card was the 109. the first problem was that the card was not responding to the remote dimmer comntroller commands. so we assume the lights were about 80% dimmed. anyway, pretty sure like you say, it was a resistance problem in the card. The instant we bypassed the card, the load was normal.

PS, my "know it all" boss called Safefty meeting this morning and he never showed up. Dude's got issues. 20 service electricians and 4 project managers waitng for the electrical god himself. go figure...:001_huh:



scameron81 said:


> If this is a GP dimming panel (and it sounds like it is) buying a new panel won't change anything other than getting you new cards. The actual dimming technology hasn't changed in those twenty years. The 109V, was that the line side or the load side of the dimming card. By default the dimming cards are set at a maximum of 90% so even when you are at 100% on the grafik eye you're still only putting out approx 90% of the voltage. the dimming level vs actual voltage isn't going to be one to one relationship because of the way your eyes perceive light levels.
> 
> The dimming cards don't change the cycles what they do do is "chop" the sine wave which lowers the voltage and brightness of the lamp. Did you try dimming the circuit to see how the current changes? It's possible there is a high resistance ground fault in the dimming card which could cause the overload as well. Having the load type setup wrong could also cause some trouble but if the system has been in service for many years and now is suddenly having problems I would suspect a bad card.


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