Can switching on fluorescent lights trip a GFCI?

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joemly

Member
I wired a switch for basement fluorescent lights to be protected by a GFCI. But intermittently, when the switch is turned on, it trips the GFCI. It only happens right at the point that the switch is first turned on, but it doesn't happen every time. I checked all the connections and everything seems to be fine. These are 4 ft. 2-lamp T12 and T8 fixtures. Is there some surge when the ballasts first start up that might be tripping the GFCI on occasion?

Many thanks for any help.

Joanna Sharf
Cornish, NH
 

Smart $

Esteemed Member
Location
Ohio
Seems to me you answered your own question, and are just looking for confirmation. On that note, yes...
 

joemly

Member
Why use gfci Electronic ballast will cause this problem

Thanks. I wanted to protect the switch because it's in an unfinished basement, but I didn't realize that the ballast would cause the GFCI to trip -- until now.

Many thanks.
Joanna
 

joemly

Member
I had a receptacle type GFI with the breaker feeding it in the same cubical yesterday. When I move the breaker paddle to the "ON" position the GFI tripped.

I'm not sure what you mean by the same "cubical". Does this have to do with fluorescent lighting?

I'd appreciate a little more clarification. Thanks very much!
Joanna
 

readydave8

re member
Location
Clarkesville, Georgia
Occupation
electrician
I wired a switch for basement fluorescent lights to be protected by a GFCI. But intermittently, when the switch is turned on, it trips the GFCI. It only happens right at the point that the switch is first turned on, but it doesn't happen every time. I checked all the connections and everything seems to be fine. These are 4 ft. 2-lamp T12 and T8 fixtures. Is there some surge when the ballasts first start up that might be tripping the GFCI on occasion?

Many thanks for any help.

Joanna Sharf
Cornish, NH
I had a similar service call recently, but:

Fluorescent was not GFCI protected, switch connected on line side of GFCI receptacle.

Fixed it by changing out Chinese no-name GFCI to P&S
 

SG-1

Senior Member
I'm not sure what you mean by the same "cubical". Does this have to do with fluorescent lighting?

I'd appreciate a little more clarification. Thanks very much!
Joanna

Sorry about the confusion.

The breaker & the GFI receptacle were within sight & sound of each other. Their was nothing plugged into the receptical. No other circuits were on the breaker. When I moved the breaker paddle to "ON" the GFI tripped. This was not the first one I have seen do this.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Is it a cheap or worn switch ? You might be sizzling inside the switch?
if you are lucky (and there is not a lot of solid evidence that it would actually work) an AFCI device might trip over sizzling. Not so for a GFCI.

However really high dV/dt transients might be causing enough current to flow through capacitive leakage paths that the GFCI would trip.
 

xformer

Senior Member
Location
Dallas, Tx
Occupation
Master Electrician
the reason for the intermitent gfci tripping is because to the capacitor associated with the core and coil ballast fluorescent fixture. the Capacitor in the circut usually uses a neutral to bleed off any voltage on it. depending when the switch is opened to turn the fixture off, the capacitor discharge could cause the gfci to trip.
 

cadpoint

Senior Member
Location
Durham, NC
the reason for the intermitent gfci tripping is because to the capacitor associated with the core and coil ballast fluorescent fixture. the Capacitor in the circut usually uses a neutral to bleed off any voltage on it. depending when the switch is opened to turn the fixture off, the capacitor discharge could cause the gfci to trip.

In red is there any way this is identified (granted it might have a line diagram) in each fluorescent?
Or are you speaking of a CAP. that is screwed into the chasis?

Is it not in fact a default to assume all electronic ballast have a CAP?
I'm just thinking out loud...

Oh does it matter that there are two different type of lights, IE two different types of ballasts?
 

xformer

Senior Member
Location
Dallas, Tx
Occupation
Master Electrician
In red is there any way this is identified (granted it might have a line diagram) in each fluorescent?
Or are you speaking of a CAP. that is screwed into the chasis?

Is it not in fact a default to assume all electronic ballast have a CAP?
I'm just thinking out loud...

Oh does it matter that there are two different type of lights, IE two different types of ballasts?

I was thinking out loud when i responded to the OP. :) I personally ran into the situation answering a trouble call at a residence. Can't remember exactly the configuration of the ballast, but a switch and light were fed from the load side of a GFCI. Occasionally when the switch was turned to the off position, the GFCI would trip. I am not sure about the different types of ballasts.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
the reason for the intermitent gfci tripping is because to the capacitor associated with the core and coil ballast fluorescent fixture. the Capacitor in the circut usually uses a neutral to bleed off any voltage on it. depending when the switch is opened to turn the fixture off, the capacitor discharge could cause the gfci to trip.

Even with a capacitor, you have to have a complete circuit. The discharge current of the capacitor will still be balanced through hot and neutral unless one end of the capacitor is connected to ground rather than the neutral. That would not be a UL compliant design except for very small EMI filter capacitors.
 

jeremysterling

Senior Member
Location
Austin, TX
I had a similar service call recently, but:

Fluorescent was not GFCI protected, switch connected on line side of GFCI receptacle.

Fixed it by changing out Chinese no-name GFCI to P&S

The other day I had a service call where when you turned on the flourescent lights in a brand new display cabinet, up to four GFCI breakers for other circuits tripped. These were not multiwire circuits and all the neutrals were individual. I one-lined it.

Fixed it by changing the name-brand T8 ballasts to Chinese made ballasts. No call back.
 
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