RFI EMI experts... need help

[Tomatoesonly]

My 600W Lumenace ballasts are giving off way too much RFI for me to feel comfortable. The lines did not include any secondary grounding.

I know right when they come on, because my TV goes all weird, and that's from across the house.

I have a bunch of foil copper tape I can use to make some sort of grounding, but I have no idea what design effectively contains the RFI. The room will get a facelift and all the walls and ceilings will be that aluminum foil insulation material. How can I use that and my copper tape to contain the interference?

My 400W units don't seem to have the same problem. Maybe those have a ground path I didn't notice.

 

[pontiac]

Try attaching a ferrite core to the ballast cord.

 

[een]

The RFI is caused by high currents at high frequencies, which is how an electronic ballast drives the bulb. The cable between the ballast and the bulb acts as an antenna. Like pontiac said try a ferrite on both the output and inlet cable. Then if you get really desperate you could replace the output cable with a shielded type (where outer layer is metal braiding) and connect the shield to the ballast case which should be grounded metal. Out of interest, does the ballast have a "FCC part 15 class A/B" label? And does it mention anything about this in the instructions?

 

[Tomatoesonly]

there really wasn't squat for instructions. I looked for any tag mentioning fcc, but didnt' find anything. What is a feeite?

 

[een]

Well it may not be FCC approved, meaning it is illegal. Normally you wouldn't care except if the interference is bad enough your government will track it down, right to your grow room...

A ferrite is a clip-on magnetic thingy for reducing the aount of RFI coming off a cable, you see them on monitor cables a lot. See this page:

http://www.ofcom.org.uk/static/arch...Radiocomms/pages/mittech/install/cmchokes.htm

Edit:
In USA it should have FCC mark, in Europe the CE mark.

 

[Tomatoesonly]

Awesome guys.. I'll go get a couple at radioshack.
I do see a CE on the tag.

 

[pontiac]

Good thing you have copper tape too, if the ferrite core dont work then i recommend you use the copper tape. Copper has poor magnetic inductance which does wonders for EMI and also does a pretty good job filtering RFI. Try wrapping the ballast and ballast cords with copper tape, and im sure you'll notice a difference in interfierence.

 

[Tomatoesonly]

Thanks Ponitiac,
I will give that a try if this doesn't work. Does the tape need to be grounded to anything or just wrapped?

 

[pontiac]

It should work by just wrapping, but give grounding a shot too. Copper tape is solderable so just solder and ground some 18AWG wire or something to it.

 

[Buzzsmirk!]

i dont think "RFI" is your problem AT ALL!!! your TV signal/picture is F---ed up and you blame RFI?????

your ballast has transformer (an inductive load) which is tryin to shift the "phase" a bit
your ballast my be messed up/"walking but wounded" and it has dirtied up you homes power quality (wave form AND frequency)power supplies in most all tv sets rely on the power to be "clean" and nearly perfect frequency ALL the timing circuits that make up your picture depend on that clock pulse be "RIGHT ON" . are you with me/understand??
make sure your grounding is good thoughout and/or try another ballast first!!!
just my opinion good luck and keep us posted!!
AINT RFI!!! not uh!~!
BUZZ!

 

[Buzzsmirk!]

BTW if its fucking your tv up it might be it doin to some of your neighbors too. and that will pique curiosity(ies) and drumroll.............service call(s)/trouble shooting!!!!
this could get you busted potentially!!!
get on this problem and solve it FAST whatever it turns out to be !!!
BUZZ!

 

[stonewall]

The LumanAce is an electronic/digital ballast, so it has no transformer. It is a high frequency switching power supply. With the ballast output in the 20- 40 kilohertz range it will interfer with the AM radio band the most.

Surely it has RFI/EMI filters on the power cord and output cables for conducted interference already from the factory.It more than likely even has a shielded power cord already. The problem is the filters do not help control the radiated RFI from the bulb itself and the output cable. The best thing you can do that will have the least impact on your grow would be to get the output cable shielded and making sure the reflector is grounded properly. All the sheilding needs to be bonded to ground properly for it to effectively attenuate the RFI noise signal.

if you shield the power supply cable, the ballast enclosure,and the output cable 360* and also ground the reflector making it a shield on all but the open side. The only transmission point will be the open side of the reflector. Minimising the rfi to the area directly under your reflector for a few yards.