Electrical question (not for a workshop, but hey)...

[Eric Larsen]

Molding aside, I'm done with my entertainment center. I've just populated the cabinets with a big LCD TV (electricity hog), a stereo amplifier (takes a lot of juice during power-up, considerably less thereafter), a computer, LCD monitor, satellite box and DVD player.

This is all one one circuit with a 15 amp breaker. (Not how I would have designed things, but that's how the house was wired.)

The breaker never trips. But when I turn the TV on, the satellite box loses power and goes through a 5-minute reset process. This is annoying.

I'm adding battery backups to obviate the problem. But I'm wondering if upping the amperage on that circuit would ease matters?

[Chris Padilla]

Sounds like a possible electrical noise interference. Try the below to see if it is a conducted noise problem:

As a possible experiment, either plug in the TV on a different circuit (or plug even if on the same circuit) or the satellite box. (Try to leave the components alone..use extension cords).

Next would be to try a surge protector on either the TV and/or the satellite box.

If neither of these work, do you have a cheapie handheld AM/FM radio? Put it very close to the TV...maybe even behind it...and turn on the radio to a clear AM station...now turn the TV on...any noise picked up by the radio? This would indicate a radiated emission problem and your TV could possibly be out of spec for such a situation. Is the TV new?

[Rod Sheridan]

Eric, it sounds like the inrush current for the TV is dipping the line voltage below the minimum required value for the satellite box.

Loose connections, low voltage from the utility or too much voltage drop in your house wiring/power bar setup.

Regards, Rod.

[Eric Larsen]

Eric, it sounds like the inrush current for the TV is dipping the line voltage below the minimum required value for the satellite box.

Loose connections, low voltage from the utility or too much voltage drop in your house wiring/power bar setup.

This is my guess. Would swapping out the 15 amp breaker for a higher amperage breaker help?

I can't fix the fact that it's only one circuit without ripping out a lot of drywall. So that's not happening. I've also got the bare minimum of electronic gizmos for an enjoyable multimedia experience, so I can't just "move the computer elsewhere." I need it right where it is.

As for RF interference, maybe but doubtful. This TV is brand new -- it's one of the Mitsubishi DLPs. I think when the lamp warms up, it's drawing a lot of power in a big hurry. The satellite box seems to be finicky about power drops, hence the APC battery Back-UPS as a fix.

EDIT -- I also had to order about 50 feet of HDMI cables, DVI-HDMI cable, RCA cables and the like to make everything pretty. That was not cheap, either.

[Chris Padilla]

15 A circuits work with #14 wire.

To go to 20 A, you would need #12 wire.

The interference doesn't have to be "RF" (which, I know, is an all encompassing term for electrical noise) but could be lower frequency: hence conducted versus radiated noise.

The TV could be sucking a lot of current and cause voltage droop but it shouldn't be doing that if it was designed properly. Just because it is new doesn't mean it isn't doing stuff it shouldn't be doing.

[Mike Lipke]

Even if you did go to a 20A breaker (which you should not), It would not matter. The voltage drop is due to the gauge and length of the wires in the walls, not the breaker.

I would try shutting off the breaker to that entertainment center, and find the nearest outlet that is not on that breaker. Run an extension cord from that outlet to the gizmo that is always resetting. You may not find one close enough for this to work, but if you do, that will prolly cure the reset issue.

[Kevin Rector]

But I'm wondering if upping the amperage on that circuit would ease matters?

If it has a 15 amp breaker then it is probably 14 gauge wire. If it is 14 gauge wire there is no way to "up the amperage" because the amperage of the circuit if controlled by the size of the wire more than the size of the breaker.

I know everything I've said has already been said, but do not under any circumstance put a 20 amp breaker on 14 gauge wire unless you're willing to risk your house burning down. It should also be noted that even if the wire is 12 gauge at the circuit box that doesn't mean that the entire circuit has 12 gauge wire (especially in old construction).

[Eric Larsen]

I know everything I've said has already been said, but do not under any circumstance put a 20 amp breaker on 14 gauge wire unless you're willing to risk your house burning down. It should also be noted that even if the wire is 12 gauge at the circuit box that doesn't mean that the entire circuit has 12 gauge wire (especially in old construction).

Don't worry, I'm not going to risk it. That's why I ask before running to Lowe's.

A battery back up will handle the voltage drop for the Satellite box, and will keep me from having to run extension cords.


Oh, here's a picture of unfinished entertainment center. I still have to mill crown and baseboard. But I dropped my new grizzly knives and broke one. So now I have to buy another $80 set. Edit - Once I install longer wires, it will look a lot neater. But that door at the bottom right is going to remain partially open most of the time for cooling.

[Jim Hawk]

You might not even need an outlet from another circuit. I'd check the voltage at the wires on the back of the outlet, then check the voltage at the outlet to see if the outlet could be causing the problem. I'd hate to have to maintain a battery backup system if all you need is a $2 outlet. If you don't have a volt meter, just plug the satellite box in a different outlet on the same circuit and see if the problem still occurs. If not, I'd try replacing the outlet.

[Gary Lange]

What is behind the wall in back of the Entertainment center. If it is another room such as a bedroom it may be on another circuit and you could run a wire from one of those outlets through the attic and down behind the TV and plug the TV into that.

[Scott T Smith]

Eric, I think that you may have a problem somewhere in your system. There are lots of home theater systems that operate just fine off of a 15A circuit.

For starters, use a volt meter to check the voltage at the outlet that feeds your equipment. Watch and see what it does while you're starting the equipment. If it drops below 105 volts (or thereabouts), this is not good.

Something else to check is the voltage on both legs of the power in your house, measure with your TV and relateded equipment turned on, as well as the other electrical things that are typically operating in your house (fridge, ceiling fans, AC, etc). You can check these at a 240V plug (such as the receptacle for an electric dryer) by measuring between the hot and the ground. As I recall, the national standard is somewhere around 118 volts, give or take.

If you measure a significantly higher voltage on one leg versus the other, chances are that you need to swap some breakers around in your load center to balance the power consumption in your house.

[Thomas Syrotchen]

FYI, DLP's use a very large bulb like projectors and some of their bulbs are actually the same models. I happened to have a manual on hand for a DLP projector I did some work with recently and took a quick look at the inrush current spec, it was 15 times the normal current use almost 30A. Since this happens when the TV is turned as Rod pointed out its likely a voltage dip from the large current load the DLP TV demands at power up. Given your limitations, a UPS might be your best choice. A quick call to the satellite provider may help as well as not all boxes are as sensitive to voltage changes as well.

FYI, I couldn't help but notice you said 50 Feet on your HDMI cable and prices eating you up. CNET did a great article on HDMI/DVI cables and prices. It would be well worth it to check it out and save you some $$ so you can replace those knives and finish up the great looking cabinet.

[Eric Larsen]

Weird. Just weird.

The problem went away on its own. I didn't do a darned thing. I'll keep an eye on it, naturally.

I still have battery systems arriving, and I plan to use them -- just to keep voltage problems from ruining my stuff. Still, weird.

[Eric Larsen]

FYI, I couldn't help but notice you said 50 Feet on your HDMI cable and prices eating you up. CNET did a great article on HDMI/DVI cables and prices. It would be well worth it to check it out and save you some $$ so you can replace those knives and finish up the great looking cabinet.

Sorry, I didn't explain it correctly. I bought 50' feet total of several cables. The longest is 20 feet.

[Robert Reece]

In my business (software), problems that "go away on their own" always "come back on their own". Of course once you put those batteries in there, things my never go back to broken again.

Still, I'd be worried that you haven't identified the problem. I would at least pull the plug and have a look at the wiring. Electrical problems that come and go usually result in something bad.