You mentioned in a post a while back about installing the MIW to get rid of a hum on a plasma. I am going to do this to fix a customers problem but I had a question. Could I install this, then install a surge protector to allow me to plug a couple things into it? Or is it not recommended and I should just plug the plasma into the MIW and thats it.

I'm not VW Power, but I know a little bit about this.

Panamax makes several models in their MIW series.

The simplest version is called the MIW Power Pro. Essentially, this is an inwall surge protector.

The one that I like is the more elaborate, several piece system called the MIW Powerkit TL (love those model numbers. If you're reading this, Bob Smith, call me and we'll talk about this....). The powerkit TL consists of a Female socket in a double gang configuration, to be mounted near the display device. It has about 30' of romex, which you or sparky runs back to the head end area. It has an additional double (or triple if you get the option) gang plate with a proprietary socket in it, which comes with a proprietary cord. That cord plugs into the main rack surge protection.
The second gang at either end is for a Panamax supplied slide in module, providing connectivity with your choice of vga or rca or what have you. Check www.panamax.com for info on those particulars.

Essentially, since the video source is plugged in to the same surge device as the display, the chances for ground potential differences between the two is eliminated.

Fred, does the MIW Power Pro then eliminate the hum bars we are seeing by itself, or is it as you say just simple protection for the TV?

It depends.

If the issue is occuring because of ground potential differences between display and source, no.

I believe that the MIW does not have an isolated ground. If you are looking to get rid of the 60hz hum pattern, use the Leviton 5380IG. This can be found at any electrical supply warehouse in the country. We use the Leviton on every job we do for the past 2-3 years. It is a gerat piece of equipment, and installs just like a regular duple outlet.

Mike

I have a problem with hum on a 50" pana plasma. I can control the speed of the lines on the screen with the dimmers in the house. Have run extension cord to every outlet in house. Will this levition outlet really clear this up.

I have used it to remove hum patterns in several plasma TVs. I have never had a problem with a TV having any kind of hum pattern because we have been using this outlet.

Mike

By the way, isolated-ground receptacles do nothing when used in non-metallic (i.e., not conduit) wiring systems. The isolation is between the third prong and the mounting strap. You still need to run a ground wire.

The green screw on the receptacle connects to the third prong hole just like in a regular receptacle. If you're using NM cable, ground isolation depends on how you connect the bare wire at its point of origination.

Larry, when you say they do nothing, do you mean they are ineffective?

No. He means they do nothing. If you are not using conduit there is no other ground to isolate from.

So then this will not solve my problem.

My situation is in a home with and the equipment is in a closet behind the plama wall. Right now I have an outlet in the closet with a surge protector with the plasma and receiver, dvd, cable box plugged into it. The hum on the plasma screen is only on the cable box. So you are saying to get the leviton outlet. Is it possible to find at Home Depot?

We are supposed to be professionals and gound loops and trouble shooting them should be on the 101 course level; no installer/tech/owner should not know how to do this. This is so basic and a question answered so often .................

When you have a ground loop your first responsibility is not to throw matterials at it but to find out where it is coming from. Most ground loops eminate from the electrical power grid but not all. CATV is a very common source of gound loops as their line amps are line powered!!! Sort of basic info here. As the lowest channel (freqency) on a cable system is 52.x MHz and 60Hz are very far apart it causes no problems for them. But we have other problems. The cable company is supposed to use taps that block this voltage from entering through the drop. Sadly their equipment does not always work. A simple CATV isolation transformer solves your problem. Indeed, isolation transfromers solve most all ground loop problems.

But before you purchase any materials you should find the offending source. Satellite IRDs?( they are supposed to be grounded and bonded by NEC but if not bonded you have 2 ground referances: electrical and dish .) CATV? Signal Activated Switchers? IR systems? Dimmers? Outlets on different phases? Once you find the offending party you know how to attack the problem. Throwing matterials at problems happenstance may work at times but is not the best method.

Alan

This message was edited by Audible Solutionns on 12/10/04 09:59 ET.

I agree with Alan. Band-aids are great but what happens when you throw products at it and it doesn't fix the problem? Never happened to you? It will.

CATV I use Jensen ISOMAX
Video I use Jensen ISOMAX
Audio I use Jensen ISOMAX

See a pattern here?

Right. NM cable and plastic (or even non-grounded metal) boxes provide the exact same isolation as isolation receptacles with insulated grounding wire in metal conduit.

This was not a comment on the effectiveness of surge-protection receptacles and other devices, only on the advantage of isolated-ground devices on non-metallic wiring systems.

Where the grounding conductor is grounded is what matters. Isolated-ground circuits have the insulated grounding wire run back to the main disconnect, where it's attached to the system ground.



Yes; you're a user! : - )

I was actually shown how to use the Leviton 5380 from someone at Progressive Audio a few years back. A custoemr had a problem where they had a +500k theater system. Linn, Crestron, Runco, B&W, Pioneer, Seating, acoustical treatment. There was a hum in the system. The guy put one of the leviton 5380's in to eliminate the hum. Ever since then our company has been using the leviton product. We have installed hundreds of the 5380 surge protectors w/ isolated gorund. This has corrected the hum patten on all of our systems we have ever had a problem with. On several instances, we have seen other firms cut off the ground on hte AC cord of the plasma, or use a gorundless AC adaptor.

I am not an electrician. I design and install home theater systems. We have an electrician that works with us and he has never mentioned any problem using the leviton 5380. I don't know if we have just been lucky and this has fixed the problem on every one of the hundreds we have put in, or we haven't run into a serious problem yet?

We did run into a different problem with a hum pattern in the cable box, and only the cable box. When cecking the contuniuty on the ground on the RF cable line to the ground on the AC outlet, we got 300 ohms (Some where around there, I can't remember). We used the Xantech Gorund BReaker to fix the problem, but it then killed the cable signal. Then we put the ground breaker on the main cable line running into the building before the amp, and this fixed the problem. Turns out that the cable system in the entire condo complex is grounded differently than the AC.

Since I am not an electrician, I cannot comment on why we have had so much success using the leviton 5380. I would highly recommend someelse to at least give it a try. It is cheaper than the Panamax MIW, and works in a single gang decora box. I would love to know the results other people find. Thanks for your input Larry, I an AC Challanged.

Mike