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surge protectors

Posted by parkplaza (My Page) on
Wed, Apr 28, 10 at 20:33

You folks use these on TVs? I have a new TV and wanted to connect it to a wall outlet installed near the ceiling. I have read surge protectors should be used...any recommendation on what type? There are so many choices...and the price range is all over the place. Is the joule rating a scam? I also saw a tiny one that has one outlet (not a strip) that fits into the plug (no cord).
Is this the classic case of get the basic cheap one, because the more expensive ones are not needed?

The store recommended a battery supply saying that was better, but it was rated for 500 watts. Considering a TV and other things (dvd player and the kids games) not sure if it would handle that load.


Follow-Up Postings:

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RE: surge protectors

IMHO, the best protection for a TV set is a decent homeowner's insurance policy.


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RE: surge protectors

Hi,

I have used surge protectors bought from E-bay which are the socket type, which I presume you will need since it is for the ceiling. The one I went for is typically used in hospitals to protect life support systems. I suppose if it is good enough for that then it is good enough for a TV. The joule rating was not super high and so far no issues.

Note I also have surge arrestor / suppressor at the mains panels coming into the house as well.

Best, Mike.


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RE: surge protectors

The Joule rating is given to indicate the level of protection from lightning strikes. Bigger is better. But be aware that these devices (MOV or metal oxide varactor) are one-time use. They sacrifice themselves to save your equipment. Partial exposure to lightning strikes wears them down. There will be no indication of failure, unless your unit has one of those failure indicator lights.

This is why the cheap ones need to be replaced every so often.

Depending on the type of TV, a 'battery type' or UPS would be a good idea. If the TV is a projector type (has a bulb inside), you should get a UPS that will regulate the incoming voltage and also give you enough time to turn the unit off if the power dies. Projector bulbs for LCD and DLP units are not cheap.

The 500wt rating of the UPS is how much it can handle if the power goes off and you want to keep the TV, kids games and DVD player going while all the lights are out in your house.


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RE: surge protectors

Does 500 watts seem like adequate capacity to handle an LCD and associated equipment? I have heard LCD use very little power.


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RE: surge protectors

UPS are not rated in watts, but V-A (volt-amps).

Watts would only work for a purely resistive load, and electronics do NOT look lie resistive loads.

Every applioance has a nameplate with power rating information on it.

Add up the amps, multiply y the voltage (120 V) and see how you stand compared to the UPS money you want to spend.

Yuo also need to watch out what type of UPS you purchase.

Some have surge protection, but many are not that adequate.
The chepaer UPs units tranfer the incoming AC power directly to the UPS outputs with limited filtering.

The more expensive UPS units are 'always on' and convert the incoming power to DC then back to AC all the time.
The y often have decent filtering on the input (to protect the UPS AC-DC conversion circuitry) and also to filter and smooth the AC the inverter generates.


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RE: surge protectors

Surges are not covered by homeowners insurance! I just found this out the hard way. I had a big surge that blew my new tv, even though it was plugged into a surge protector. My adjuster told me that only the dwelling is covered, but not any appliances or personal property. If you have a surge, you are on your own unless it burns down your house.


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RE: surge protectors

If the utility caused the surge you can request a form to turn in for reimbursement but the catch is that the problem has to be caused by improper operation of their system such as lack of maintenance or bad design. If caused by a third party then they will forward your claim on to the insurance company of the guy that ran into the power pole. Acts of god like trees falling on lines and lightening are not the utilities fault.

So many homes are full of electronics that we install whole house surge protectors by Eaton at the panel on all homes we work on and recommend that homeowners install a second at each expensive device. The first cuts it down to size and helps the second handle what's left and last longer. MOV type surge units are sacrificial and will eventually quit working. There are different grades of units.

Here is a link that might be useful: Eaton surge articles


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RE: surge protectors

Check your surge protector vendor. They may have a warranty that covers damage to protected equipment.


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RE: surge protectors

"But be aware that these devices (MOV or metal oxide varactor) are one-time use."

Metal Oxide Varistors

They can work repetitively, but each time they are forced to conduct a surge there is some damage that reduces their overall energy capacity the next time.

There is no any reliable way to measure how much capacity is remaining (thew test destroys the device).

If a very large surge occurs (a lot of energy) the MOV may be destroyed by that single event.

It all depends on how much energy the surge has, and that is a combination of voltage, current, and length of time the surge turns on the MOV, along with any current delivered by the power lines the MOV is connected across.

Even the largest MOVs cannot protect again sty a close nearby strike directly to the power lines.

What they can help with is the energy coupled into wiring from the huge magnetic field that accompanies a lightning strike.
The magnetic field is rapidly changing so any conductor in the field has a voltage generated in it.

Luckily there is not a lot of current behind the voltage spike, so the total energy is not that high.


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RE: surge protectors

So what does one do, replace them once a year? If there is no way to test them, you may be unprotected.


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RE: surge protectors

Golly by Gosh! How can so much basic information be so misunderstood? brickeyee's post above provided the answer but still people like to listen to the (commissioned) salesman that of course knows everything! ... "you need to buy a surge protector for your new TV." I was once in a store and heard a salesman claim to a customer it should be "2 x the screen size in Joules rating!" What?!!

Surges come from basically roughly four places... inside the home caused by inductive appliances turning on/off, outside the home caused by switching on the grid, lighting strikes causing an inductive voltage (EMF) onto the grid, and direct lighting strikes onto the grid.

Surge protectors may help prevent the first two, and maybe possibly the third, but ain't going do do anything for the fourth.

The term "it must have been a power surge" has been so misused over the years that it has become commonly accepted.

Electronic devices like flat panel TVs and computers have MOVs built in already. While it is a good idea to protect equipment as much as possible, sales pitches have taken over.

The earlier post about a 500 watt UPS (not VA's which would be about 300 VA, in most cases) to power a flat panel TV rated at 150-175 watts is "what are you looking to do?!" Watch TV for three minutes or safely shut down a computer before the UPS shuts down? You ain't going to be watching TV for 3 hours. If you live a a problem area for AC interruptions and noise, a UPS with a long capacity and ability to switch quickly to correct for these fluctuations would be a good idea.

Most equipment is already designed for surge protection, doubling it up with power strip protection will only help, but come on already, how many light bulbs have you seen "blow out" from power surges?

Sorry I'm not trying to criticize anybody but just trying to be real.


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RE: surge protectors

UPSs' for TVs are a scam.

Any decent strip surge protector is sufficient, get teh surge protector with a $5000 warranty from Wally World.


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RE: surge protectors

I don't now if it's a scam. I have a small power conditioner/UPS that has about 20 minutes of ride through. It keeps the DVD and the computer attached from reseting when we get a minor power hit as well as providing surge protection. Necessary? Probably not...convenient? Yeah, worth the $40 I paid for it I think.

Don't need more than about 20 seconds, which is all it takes for my generator to kick in.


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RE: surge protectors

Actually, as weedmeister mentioned earlier up in the posts, LCD projectors and DLP televisions use metal halide lamps that get extremely hot and are fan cooled (they even have air filters). When the device is turned off the fan continues to run until the lamp temperature drops back down and then the fan turns off. A quick disconnect of the power can often be fatal for these bulbs as they don't get the proper cool down cycle and the internal quartz tube cracks. For these types of televisions a UPS is highly recommended. Not to watch TV but to turn it off and let the UPS supply power for the cool down cycle.


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