PFO electronic Ballasts causing interference

[pallan]

I recently got 2 PFO electronic Ballasts that are running 2 de 250 watt PFO pendants.
Ive been noticing interference with my cable TV reception for a couple of weeks. this weekend i noticed it was caused as the lights come on on the aquarium.
anyone had this problem or know a solution. this sucks. i really like the lights but wife is tired of the interferance.
Please help.

 

[f14peter]

I'm no electrical expert, but interference is usually the result of poor/faulty/no shielding. Back in the day, car ignition sytems caused horrible interference with radios, until manufacturers came up with shielded ignition wiring/systems. Every once in a while you can still encounter this phenomenon if you drive by another car with a non/poorly shielded ignition.
I'd say there's a "Leak" in the wiring of your lights allowing powerful electrical signals out, or inadequate shielding/connections in the cable for your TV allowing the light's interference in.
Your TV cable sheilding could have been sufficient to resist any existing interference until a more powerful source (you lights) arrived on the scene. You could go around and check every junction, connection, splitter, etc and make sure they're all tightly connected and of good quality. In fact, the FCC requires that there's no leakage at all from from cabling as it could (Potentially) cause interference with radios or allow someone else to pick up the signal leaking from your system.
Most likely however, I'd think your lights are the problem. A DIY light set-up may not have shielded connections. Can't comment on a cure, other than to examine any connections for exposed wires. Distance can make a difference, although I'd imagine moving either the tank or TV farther away from each other isn't practical.
I don't know if there's a filter that could be attached to your TV cable, maybe. Sometimes though, the interference is so strong that shielding may not be able to hold it in or keep it out.
As for the lights coming on, are you referring to other lights, and are they on an electric/digital timer? If so, the interference may be strong enough to wack out the timer.

 

[pallan]

i dont know what to think. this is not a good deal at all. put all this money into these lights now their screwing up my other things.
to answer you questions. all cables are connect tightly as i can get them. the interfernece starts as soon as the metal halides come on and stops as soon as they are shut off. This is not a DIY fixture but a store bought metal halide system. you would think they would be shielded enough.
Im contacting the sales person who sold this and also PFO tomorrow. this is ridiculous.
bought ready to throw in the technology towl. and go back to horse and buggy days.
Thanks for the response ill let you know how this turns out.

 

[squidd]

bought ready to throw in the technology towl. and go back to horse and buggy days.
I agree...who needs cable when you have a reef tank...

 

[scsinet]

Likely, the leakage is being caused by EMI (electro-magnetic-interference) being passed along the hot wires of your home's wiring.
There are several things you can try.
1. Your home is fed by two "phases" of power. Standard 120 volt circuits can be on one or the other, and the various circuits in your home are divied up between the two. Likely, your aquarium circuit and TV circuit fall on the same phase if you are seeing this problem. Try running a heavy duty extension cord to your tank and running it on various circuits in the house. See if you can find one that makes the interference go away. If you can, then you've isolated the problem. Leave the tank on the circuit that fixes the problem. Of course that may not be convenient. If the tank and the TV normally are controlled by the same circuit breaker, then you may need ot run or have run a dedicated circuit for the tank that is on the other "phase." If you find that the TV and the tank are normally on different circuits, then you can get an electrician to come in and rearrange the circuits in your breaker panel so that the tank and the TV are on different phases. Of course you can do that yourself if you are comfortable inside your breaker panel, but most people aren't.
2. You can install a GOOD surge protector/noise filter on your tank or TV or both. The only decent quality surge protectors out there, IMO, are the Tripp-Lite Isobar Premium units. They cost a pretty penny, but have noise isolated sockets on them that may solve the problem.
3. Check to be sure that the ground wire on your cable TV line coming into the house is firmly grounded. There should be a little block on the ouside of the house near your phone lines and electric meter. The block should have a ground screw, with a wire that is clamped to it (bare or green) and connected to a ground rod driven into the earth. Make sure that's intact, firm, and no corroded.
4. Make the cable company fix it. It's their responsibility to give you a clear signal. FCC part 15 stipulates that it's not technically their legal obligation to do it, but they usually want to please their customers, especially with satellite being so appealing.

 

[pallan]

Originally Posted by SCSInet
4. Make the cable company fix it. It's their responsibility to give you a clear signal. FCC part 15 stipulates that it's not technically their legal obligation to do it, but they usually want to please their customers, especially with satellite being so appealing.
Cable company came out today and redid the cables to the TV and the box. they also hooked up a powered signal amplifier to the cable and this has all but alleviated the problem plus i got better picture now as well ***) ***)
they are coming back tomorrow to look at the outside of the house and redo the lines out there and the Traps.
it is still able to be seen ever so slightly on the big screen tv. and i do plan on looking at rearrangling some power options although i did try a extension cord to another place that was not on the same circuit and still had the problem.
my question now is this. im outcompeting the signal now and i find it unlikley but could the ballasts be bad should they be replaced or is this just interferance and thats that. it does this wether 1 ballast is on or the other is one so like i said i dont think it is a bad ballast. but just wondering dont want a fire hazard or anything like that.

 

[scsinet]

It's certainly not a bad ballast. Electronic ballasts oscillate at around 45KHz as part of normal operation, which is right in the range to cause problems. I wouldn't consider a bad ballast as a culprit.
Remember that simply moving the tank to a different circuit probably won't fix it. You need to get the TV and the tank on circuits that are on different phases. An experienced person can tell by looking at the breaker panel in your house (even without removing the cover), but how to tell can vary from panel to panel, so it's not always cut and dry.
The best thing to do is just try about half a dozen or more different circuits. By doing this, it's a pretty good chance you'll hit on one sooner or later. If the problem never goes away, it's pretty safe to assume that the phases are not part of the problem.
Another thing that's a prime suspect here is the cabling your walls. Home builders (and sometimes cable companies) tend to install RG59/U coax in the walls of houses under construction, unless specifically told otherwise. While this is "adequate" for TVs, it's hardly the best (in fact, I'd call it the worst), as it only provides a thin braid of sheilding, with holes in the shield big enough to drive a bulldozer through. The type of cable that should be used is RG6/Quad. This type of cable contains 2 foil layers and 2 braided wire layers of shielding. Unfortunately it's rare that the cable is installed in such a way that makes it easy to replace. If you are lucky enough to be able to get to your TV cable, check what kind it is. If it's possible to replace it, that's another way you can reduce the problem.

 

[wattsupdoc]

Electronic ballasts 101:
Electronic ballasts have many advantagtes over magnetic ballasts. They are more effiecient, generally operate better than magnetic ballast in higher temps., operate cooler, start up rapidly under lower temperatures(40 degrees and below), can be dimmable, have a much longer life. They do have some disadvantages though. The number 1 disadvantage...harmonics. These are spikes in the circuit caused by the electronically manipulated sine wave. They are accumulative in the circuit in that the neutral wire carries the combined load as opposed to balancing out. What this means is that the white wire coming back from you're plug in the wall carries the "unused portion" of the power back to the panel box. Normally the combined load on this wire is balanced and cancelled out on a circuit which the neutral is being shared between legs. However, harmonic loads are not cancelled out, instead they accumulate.These spikes can and will cause interference on other electronic equipment i.e. you're TV or computer etc. if... they are located on the circuit with the EB, on a circuit which the neutral is shared, there are poor connections at the service location on the neutral or ground wires, or there is an inadequete ground for the building service.
First choice..
Add a dedicated circuit for the aquarium.This is a good idea for several reasons, and everyones aquarium IMO should be on one.
Check the connections on the neutrals in the panel.
Check the connections on the ground and make sure there is an appropriate "bond"in place.
P.S.Let the cable company do whatever they want to relieve the situation.
HTH