Need help regarding amps and surge protector

Old 06-04-14, 02:55 PM
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Need help regarding amps and surge protector

First of all, I have very little knowledge about things like this, but I was hoping I could get some help on a site like this instead of someplace like yahoo answers :P

Basically, in my room I have a receptacle on the wall with 2 outlets, both 3 pronged (grounded). The top outlet hasn't worked for a few years, and I'm not sure exactly why, but for whatever reason 3 pronged plugs won't fit into it. I'm guessing it will have to be replaced.

So in the bottom outlet, that's where I have everything plugged in. I use the following 12 outlet surge protector to plug everything in - Belkin 12 Outlet Home/Office Surge Protector with Phone/Ethernet/Coaxial Protection and Extended Cord 4156 Joules: Electronics

Yesterday, I got a 5,000 BTU window air conditioner installed, which says it uses 3.9 amps and 446 watts. Frigidaire 5,000 BTU Window-Mounted Room Air Conditioner

So now on the surge protector I have

my gaming PC (650 watt PSU, but it would be using a lot less on average, with maybe 500-550 watts at full load)

42" TV that uses about 75 watts on full load

a PS3 (turned off since installing the air conditioner),

cable box for TV,

a nintendo 3DS,

a ~30 watt monitor

a 10 watt tablet charger

a DSL modem

the 3.9 amp/446 watt air conditioner

I know that's a lot, and the outlet is probably 15 amps since that's what standard bedroom outlets are, but I don't think I would be at anything more than 11 or so amps at full load.

The problem I'm having is that occasionally, a few times a day when the compressor starts on the air conditioner (that's what I'm assuming because the air conditioner makes a certain noise when this happens), my monitor goes black for 2-3 seconds. I don't know exactly what's happening, because if I was using too much power what I'd assume would happen is EVERYTHING would turn off. Not only that, but the monitor doesn't appear to be turning off at all, the screen just goes black. I don't notice the power light going off.

I'm wondering if the air conditioner is 'surging', using more than 3.9 amps during certain times (I read something about appliances using a lot more power when they first turn on). If it is, could the surge protector be the problem? The plug for my monitor is next to the air conditioner in the surge protector, that's the only reason I can think of as to why the monitor would be going black but nothing else would turn off. Would there be any difference using the air conditioner in it's own outlet after getting it fixed, or would it not make a difference because the total amps would still be the same?
Old 06-04-14, 03:38 PM
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That A/C unit should be on it's own 20 dedicated circuit.
Old 06-04-14, 03:40 PM
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Are you sure that the top portion of the receptacle isn't switched? In other words, there is a switch on the wall that sends juice to it. No matter if that's the case or not, the load you have on that circuit is probably too much, for it to handle. It may not be due to what's in that room. I'm sure that there are other things on that same circuit. If you were to shut the breaker that controls that receptacle, I'm sure that other rooms would be affected. That's one way to test it.
Old 06-04-14, 06:56 PM
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my monitor goes black for 2-3 seconds
I'm wondering if the air conditioner is 'surging', using more than 3.9 amps during certain times
There is no surging (layman's term for when they don't understand normal of equipment or the circuit). The air conditioner normally will momentarily draw around 3 times full load amperage when starting the compressor which momentarily lowers the voltage. You shouldn't have sensitive electronics on the same circuit as an air conditioner.
Old 06-04-14, 07:30 PM
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Sounds like a voltage sag is causing issues.
Old 06-06-14, 06:02 AM
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The numbers provided are to simplify your arithmetic. For example, a 1 amp light bulb may consume 8 amps when it first starts. A 10 amp lamp cord will carry something less than 60 amps. So yes, many items surge (cause a large current and low voltage; also called a sag). To keep it simple, the numbers we give you should sum to well less than 15 amps.

A surge protector is for something completely different (a large current and high voltage). It should not affect, in any way, that or other types of surges.

Connect an incandescent bulb to that power strip. Does the light bulb dim significantly when an air conditioner starts (ie by 20%)? If yes, then you have a wiring problem. Somewhere in the various connections back to the breaker box, some connection is insufficient. The air conditioner should start without cause the bulb to dim IF wiring is properly connected at every receptacle and wire nut.

In most cases, the dimming only reports a minor problem. In rare cases, it reports a major human safety issue.

Electronics are not sensitive. Electronics are robust. Electronics should work just fine on voltages so low as to be harmful to the air conditioner. If voltage drops even lower, then electronics simply power off without damage. Apparently that is what the monitor sees - a voltage dropping so low that a dimming incandescent bulb will make a serious defect obvious.

BTW, shape of the AC plug and receptacle says that is an 'up to 15 amp' circuit. Which means your arithmetic should sum to something less than 13 amps.

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