ScaldedDog
Well-known member
Based on responses in another thread, I thought a little poll might be in order. Please let us know what kind (length, bulb count, brand and source) of T8 fixtures you have.
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T8 RFI experience, participate if you have >= 8 T8 fixtures
- Thread starter ScaldedDog
- Start date
pjm1
Member
I hope more people get in on this pole, I am interested to see if building materials do play a part in the RFI.
Burl
Well-known member
Would it matter if you used an external antenna?
Wood build with RFI noise
4ft
3 and 4 bulb t8 fixtures
Metalux
I have moved the radio, antennae, changed the cable, put an external ant. mounted at peak of roof. Nothing has helped. Ran an extension cord from house to detached garage, still have RFI. Shut off the lights and the RFI noise is gone.
4ft
3 and 4 bulb t8 fixtures
Metalux
I have moved the radio, antennae, changed the cable, put an external ant. mounted at peak of roof. Nothing has helped. Ran an extension cord from house to detached garage, still have RFI. Shut off the lights and the RFI noise is gone.
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fotoflojoe
Well-known member
This poll is kind of timely for me. On the weekend before Thanksgiving, I installed 16 four-foot, two-bulb T8 fixtures in the garage. After reading about RF interference, I was expecting it to be a horror show. No interference to speak of so far though. It actually only hit me a few days ago, when I realized that while standing at my workbench, I was talking on my cell phone and had a static-free radio (on FM) playing in the background.
Palmetto
Well-known member
Metal building
(6) 8' long 4-bulb T8 fixtures.
I have RFI. I cant listen to the radio with the lights on.
Brand: Cooper/Metalux from Lowes.
(6) 8' long 4-bulb T8 fixtures.
I have RFI. I cant listen to the radio with the lights on.
Brand: Cooper/Metalux from Lowes.
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Stang65Fst
Member
- Joined
- Apr 13, 2008
- Messages
- 18
WOW RFI with T8 never thought of that one. Any lights that don't give that much RFI off for a shop?
Re: T8 RFI experience, participate if you have >= 8 T8 fixtures
24 HD and Lights of America T-8 4'
8 Lights of America T-12 4'
30' x 40' Gambrel Wood Barn
No interference on FM, Cell, or 5.8 Ghz cordless
WiFi works fine also. ~ 75 ft from router
Only noise is when the T-12 are switched on I can hear a slight hum from the panel. If I push on the breaker it goes away. Not interference or very loud, but still annoying if you are in that corner of the garage.
Dave
________
STARCRAFT 2 REPLAY
24 HD and Lights of America T-8 4'
8 Lights of America T-12 4'
30' x 40' Gambrel Wood Barn
No interference on FM, Cell, or 5.8 Ghz cordless
WiFi works fine also. ~ 75 ft from router
Only noise is when the T-12 are switched on I can hear a slight hum from the panel. If I push on the breaker it goes away. Not interference or very loud, but still annoying if you are in that corner of the garage.
Dave
________
STARCRAFT 2 REPLAY
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mmhouse
Well-known member
Maybe a dumb question but what impact would the number of fixtures (>=8) have on the presence or absence of RFI?
66HertzClone
ALLIANCE MEMBER
I need to add a few fixtures in my garage and have been following this subject closely. I was in HD today and asked a friend of mine who works in the lighting department about the RFI interference issue. I don't know if it makes any difference, but he pointed out that there are two different ballast units for T8 bulbs. One is listed for residential use and the other states on the unit commercial use only. Makes me wonder if there is any possibility that one or the other ballast causes the RFI.
D Ellefson
Member
- Joined
- Jun 26, 2008
- Messages
- 20
I don't post here often, but since I was all over this topic a month ago when I was installing my lighting, I thought it was time to contribute.
2 Car attached garage
CBS construction
4 ft, 2 bulb T8 Fixtures
Qty 5
From Lowes - I don't remember the brand, but the fixtures were about $18 each.
These are hanging fixtures with a plug. I have attic access so I removed my single switched bulb and ran the circuit from that point around the garage adding a metal outlet box (the kind with a bracket that you can hammer in to the joist) for an outlet above each fixture. Someone here in the lighting forum did the same thing so thanks for the idea. I think they mentioned wanting to shorten the cords but I digress. Basically, there is an outlet in the ceiling above each light. I used 12AWG Romex to wire and there is a threaded wire clamp going in and out of each box to secure the Romex. I made sure that I had a solid ground connection at each outlet and back to the panel. I have absolutely no problems with RFI using either my cheap $12 Walgreens radio or my more expensive stuff. FWIW, I think improper grounding is the cause of most (but not all) RFI interference problems.
Best of luck to all those working on their lighting projects.
2 Car attached garage
CBS construction
4 ft, 2 bulb T8 Fixtures
Qty 5
From Lowes - I don't remember the brand, but the fixtures were about $18 each.
These are hanging fixtures with a plug. I have attic access so I removed my single switched bulb and ran the circuit from that point around the garage adding a metal outlet box (the kind with a bracket that you can hammer in to the joist) for an outlet above each fixture. Someone here in the lighting forum did the same thing so thanks for the idea. I think they mentioned wanting to shorten the cords but I digress. Basically, there is an outlet in the ceiling above each light. I used 12AWG Romex to wire and there is a threaded wire clamp going in and out of each box to secure the Romex. I made sure that I had a solid ground connection at each outlet and back to the panel. I have absolutely no problems with RFI using either my cheap $12 Walgreens radio or my more expensive stuff. FWIW, I think improper grounding is the cause of most (but not all) RFI interference problems.
Best of luck to all those working on their lighting projects.
FakeName
Well-known member
Been monitoring this, as I'm choosing lights for my build.
Other big factor is the radio itself. AM or FM? Is it a high-quality, metal cased receiver, or a plastic walmart? Is there RFI on other inputs, like CD? Does relocating the speakers (if detachable) change the nature of the problem?
fn
Other big factor is the radio itself. AM or FM? Is it a high-quality, metal cased receiver, or a plastic walmart? Is there RFI on other inputs, like CD? Does relocating the speakers (if detachable) change the nature of the problem?
fn
Palmetto
Well-known member
Grounding question:
My 6 fixtures are on one circuit. I tied the bare ground wire, in my 3 wire romex, to the green ground screw of each fixture. This bare wire goes back to the panel and ties into the ground bus.
I keep reading about everyone saying "properly grouned", and I am wondering if there is a different way to ground them?
My 6 fixtures are on one circuit. I tied the bare ground wire, in my 3 wire romex, to the green ground screw of each fixture. This bare wire goes back to the panel and ties into the ground bus.
I keep reading about everyone saying "properly grouned", and I am wondering if there is a different way to ground them?
buening
Well-known member
I too was wondering that Palmetto. Mine is grounded the same way, using the ground wire from the romex to the green screw in each fixture.
And to clarify mine, I have 4 eight foot fixtures that use 4 four foot bulbs....so essentially I only have 4 ballasts but the amount of bulbs is the same as 8 four foot fixtures. I have RFI interference and my radio is a cheaper plastic boombox. My lights are from Lowes and I am not sure if the ballast is residential or industrial.
And to clarify mine, I have 4 eight foot fixtures that use 4 four foot bulbs....so essentially I only have 4 ballasts but the amount of bulbs is the same as 8 four foot fixtures. I have RFI interference and my radio is a cheaper plastic boombox. My lights are from Lowes and I am not sure if the ballast is residential or industrial.
Palmetto
Well-known member
Re: T8 RFI experience, participate if you have >= 8 T8 fixtures
I have three banks of 8 lights that are fed by one 20A circuit and run through a three gang switch. My other two banks of 4 each are on separate circuits with their own switches. They are all plugged into outlets that ground back to the main panel. I switched my receiver over to AM and I can hear some buzzing on all but the strongest stations. The receiver is about 9' from the nearest light and has a coil antenna on the back.
Dave
________
WEBSITE DESIGN
I have three banks of 8 lights that are fed by one 20A circuit and run through a three gang switch. My other two banks of 4 each are on separate circuits with their own switches. They are all plugged into outlets that ground back to the main panel. I switched my receiver over to AM and I can hear some buzzing on all but the strongest stations. The receiver is about 9' from the nearest light and has a coil antenna on the back.
Dave
________
WEBSITE DESIGN
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rocco
Well-known member
most anybody that is experiencing RFI noise has T8 electronic ballasts that have a high THD %, any spec grade product out there will have at least <20% THD ballast or better, heck the standard for most commercial Instant start T8 ballasts nowadays is <10% THD. People, don't buy the residential grade products at Home Depot/Lowes/etc.. and expect commercial grade ballasts, they only offer the offshore ballasts to keep their costs down.
*Always buy your lighting products at a wholesale electrical distributor and ask for better then residential grade ballasts, heck ask for <10% THD ballast in any fixture you buy.
I have 12 x 8ft 4lamp T8 with 1 ballast per fixture, <10% THD electronic ballasts and zero RFI issues.
*Always buy your lighting products at a wholesale electrical distributor and ask for better then residential grade ballasts, heck ask for <10% THD ballast in any fixture you buy.
I have 12 x 8ft 4lamp T8 with 1 ballast per fixture, <10% THD electronic ballasts and zero RFI issues.
rocco
Well-known member
HD in Canada does not sell any T8 fixtures with true commercial grade ballasts, at least to my knowledge.
Tom McDermott
Active member
The Federal Communications Commission (FCC) in the USA lists equipment that may potentially cause radio/television interference under Part 15 of their rules (47CFR). There are two categories: Class A and Class B. Class A is less stringent, and is for business and non-residential applications. Class B is more strict, and is for residential applications. Your home computer for example must be listed under Part 15, Class B. I have not seen any electronic ballasts listed for Class B use (they may exist, I just have not seen one).
The rules state that you are responsible for any interference generated (so if your neighbors complain, ya gotta do something about it).
If you have a metal building, it may be shielding or greatly attenuating your radio receiver from most of the stations you listen to since they come from outside the metal shell. The lights however are inside the metal shell, and are not attenuated. If this is the specific problem you have, getting an outside antenna hooked up to your radio will greatly help the situation.
Grounding does not in itself reduce the interference. Sometimes it helps, sometimes it hurts, and sometimes it makes no difference. Shielding and filtering does help. The problem is in the ballast and/or bulbs themselves. Shielded fixtures are one solution. Powerline RFI filters at each fixture are another.
-- Tom
The rules state that you are responsible for any interference generated (so if your neighbors complain, ya gotta do something about it).
If you have a metal building, it may be shielding or greatly attenuating your radio receiver from most of the stations you listen to since they come from outside the metal shell. The lights however are inside the metal shell, and are not attenuated. If this is the specific problem you have, getting an outside antenna hooked up to your radio will greatly help the situation.
Grounding does not in itself reduce the interference. Sometimes it helps, sometimes it hurts, and sometimes it makes no difference. Shielding and filtering does help. The problem is in the ballast and/or bulbs themselves. Shielded fixtures are one solution. Powerline RFI filters at each fixture are another.
-- Tom
Just checked my ballasts. They are Triads and are listed in their specs as being less than 10%THD. My AV stereo receiver (PIONEER) is not being used because thr RFI is very bad. Cheap boombox style radio is only slightly better. The receiver has had ant. moved outside and shielded cable used and the RFI didn't change. I even ran an extension cord from the house with no change. Originally there was the cheap t12 fixtures that can be purchased for $10.00 at Lowes in the garage with NO RFI noise and these were the China specials.
rocco
Well-known member
you may have grounding issues then. 95% of the complaints i've seen over the years stem from high THD econo ballasts.
nissan_crawler
Well-known member
Well, I voted no, but then saw the AM part. FM is better with 18 t8's than it was with a single t12, but AM ***** with the t8's. I never had it on AM before, so I don't know if that was the same with the t12's or not. I haven't had AM on for years.
rinny_tin_tin
Well-known member
As a means of suppressing RFI that may impress upon the power lines via back emf, try twisting the power conductors feeding the offensive appliance to invoke the common-mode noise rejection technique. Using grounded metal conduit through the power run should also attenuate RFI. Whatever radiation occurs at the appliance will need additional shielding if not already supplied.
I see I'm not the only person trying to figure out RFI with my lights. I have 10, 4 bulb fixtures with the 5000 series lamps in my shop & they tear my radio to shreds. I got them thru an electrical supply house. Crescent is the brand. Fortunately I have Wi Fi out to my shop & am listening to internet radio thru my receiver. I'm going to take my Monster HTS power center out of the house & try it in the shop to see if that filters it out. I can watch movies in the house running on a generator with no RFI at all, so it might work. I just need to find the time. 
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Identaltech
Well-known member
I have 8 4 footer t8 and the only RFI I have is with anolog signal for my T.V.
when I am watching digital I have no problems.
note t.v. antena is in the attic of the garage
was going to relocate antena but since all t.v. signals are going to digital. I thought no big deal.
I have no other interference.
when I am watching digital I have no problems.
note t.v. antena is in the attic of the garage
was going to relocate antena but since all t.v. signals are going to digital. I thought no big deal.
I have no other interference.
RoadBeater
Well-known member
I have visited this forum for a while, but had to log in to share the RFI pain. I have three different brands of 4' T8 fixtures in my garage, and only the Lithonia's with Sylvania ballasts give me RFI interference. Unplug them and it's gone. I actually bought the T8's based upon this site, and they work great, but tired of listening to CD's. I also have tried grounding the radio and have an external antenna. Interestingly enough, I took one of the fixtures apart to verify the ballast was grounded, and there was a phone # for questions. I called it, they state I should have bought the residential ballasts, that the commericial have more RFI issues. I originally bought the commercial fixtures 9used), because I read the problems with cheap fixtures. Sorry for the long (first) post, but I am looking for help, not wanting to change ballasts....
I voted in the poll. I too have RFI interference; some FM stations are ok, but none are good. Of course the ones that I want to listen to are horrible. I have 4 Lithonia 8' T8 lights and 2 4' T8 lights. Turn on the switch and the car radio, or wired radio goes to static. I was beginning to try alternate antennas and such, but from this thread it appears none of it will help. I have tried sanding the grounding spot on the lights, but it doesn't seem to help.
Just checked and my 4ft T8 don't cause any interference, it is only my 8ft lights that cause the problem.
Has anyone found anything that works at all?
Just checked and my 4ft T8 don't cause any interference, it is only my 8ft lights that cause the problem.
Has anyone found anything that works at all?
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OP
ScaldedDog
Well-known member
I spoke with Lithonia this morning, and their rep recommended their part number TC 2 32 120 GESB, which looks to me to be the same light from HD that everyone is complaining about. She did offer to research the issue, if people have this light and RFI issues.
ACTION ITEM FOR THOSE WITH LITHONIA T8'S AND RFI: Get a part number off one of your ballasts - or a few of them, in case they are not the same - and post it here. I'll take the info to Lithonia and see if we can get clarification, if not satisfaction.
Mark
ACTION ITEM FOR THOSE WITH LITHONIA T8'S AND RFI: Get a part number off one of your ballasts - or a few of them, in case they are not the same - and post it here. I'll take the info to Lithonia and see if we can get clarification, if not satisfaction.
Mark
Vicious_Cycle
Well-known member
I'll try to get out there this weekend and get some numbers off of mine.
I have twenty of the 8-ft fixtures that take four 4-ft T-8's in a 30x48 wooden pole barn with metal roof. No radio works well within 10 feet of that barn when the lights are on! Car radio, home stereo, boom box and portable radio all have massive static, even when I have just one row of 5 turned on. The more I light up, the worse it gets.
I have twenty of the 8-ft fixtures that take four 4-ft T-8's in a 30x48 wooden pole barn with metal roof. No radio works well within 10 feet of that barn when the lights are on! Car radio, home stereo, boom box and portable radio all have massive static, even when I have just one row of 5 turned on. The more I light up, the worse it gets.
RoadBeater
Well-known member
I have three different styles of T8's in my garage, all 4'. Both of the sylvania ballasts are in Lithonia lights.
The good ballasts are:
Sylvania QT 2X32/120 IS-SC
Advance REL-4P32-RHTP
The Bad:
Sylvania QTP 3X32T8 UNV-ISN-SC
The good are fine, but as soon as I plug one of the bad in, it's fuzzy radio time. Yes, the fixtures are grounded.
The good ballasts are:
Sylvania QT 2X32/120 IS-SC
Advance REL-4P32-RHTP
The Bad:
Sylvania QTP 3X32T8 UNV-ISN-SC
The good are fine, but as soon as I plug one of the bad in, it's fuzzy radio time. Yes, the fixtures are grounded.
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OP
ScaldedDog
Well-known member
Thanks Roadbeater!
Hey Vicious, what did you find?
Mark
Hey Vicious, what did you find?
Mark
burleymike
Well-known member
Here is a website with some good info about ballasts and lamps. It appears that the RFI comes from the lamps as well as the ballast.
http://www.labs21.org.uk/DGHTM/DGHtm/electronicballasts.htm
http://www.labs21.org.uk/DGHTM/DGHtm/electronicballasts.htm
M. MYERS
Well-known member
T-8 in a block building with metal roof, no interference.
not a place to check
Melvin
not a place to check
Melvin
Vicious_Cycle
Well-known member
I found that I have asthmatic bronchitis and my 6 year-old daughter has the flu! Not a good weekend. Needless to say, I haven't made it out to the shop.
RoadBeater
Well-known member
Ouch....it's never fun when the kids are sick.
For the record, all my lights have the same 5000K bulbs in them. I learned about the whole color of lighting on here, and the 5000K are definately the way to go. It's like a doctor's office (minus the sterile smell...)
For the record, all my lights have the same 5000K bulbs in them. I learned about the whole color of lighting on here, and the 5000K are definately the way to go. It's like a doctor's office (minus the sterile smell...)
Vicious_Cycle
Well-known member
Okay, finally made it out to the shop and took a peek at my ballasts. These things do NOT get along with radios. Sound rating = class A.
The sound rating on a ballast is an indicator of the ballast noise (audible hum), and has nothing to do with RFI. It does show that it is an "outdoor" type ballast and was likely made with little consideration to RFI reduction...
Vicious_Cycle
Well-known member
Synergy
Well-known member
I am running old electrical, non grounded, while I am redoing the new sub in my garage. I have (3) 4' 4 bulb t-8 recessed troffers with electronic ballasts made by Cooper/Metalux I got from Lowes. The are wired in non grounded in a 1960 built wood frame garage and I have zero interference with any radio signal. I actually have a troffer about 4' above my stereo.
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