Question Power issues with old wires.

[Karcen]

Okay so this is a bit hard to explain as I already know the cause of my problem and likely there isn't much of a solution but I am wondering why it happens.

What happens is sometimes when my house AC is on my back up power supply/ surge protector will trip as and not let my computer start up. For details I have a 900 watt or volt back up abd a 1000 psu in my computer. My house is old built in like the 60s and is still using those old wires. The AC and my room share the same circuit.

So my main question is why is it tripping when the AC is on is it detecting the power draw as a surge or a Brown out or something?

 

[jsmithepa]

detecting the power draw as a surge or a Brown out or something?

^Exactly.

Your potential fix is to place PC on another circuit, failing that, change room, run a beefy extension cord to outlet in the hallway which maybe on another circuit.

 

[Karcen]

^Exactly.

Your potential fix is to place PC on another circuit, failing that, change room, run a beefy extension cord to outlet in the hallway which maybe on another circuit.

Could going down to maybe an 800 fix this I used to have a computer with a 750 but no back up psu abd it never did this?

 

[AllanGH]

Yup....when the AC starts-up, two highly inductive devices are pulling power from the line, and generating a counter-electromotive force--the compressor and the fan motor(s). This causes a "dip" in the voltage that you are seeing on the outlet that is on the same branch circuit as the AC unit.

Ideally, the AC should be on its own, dedicated circuit; and, if it is not, you are going to have no end of problems with computing equipment sharing the same branch circuit.

Same goes for things like refrigerators, dehumidifiers, freezers, refrigerated water coolers, and, interestingly enough, facsimile machines (if such dinosaurs still roam the Earth). Even other computers can cause you problems--especially if you don't have a safety ground wire wired to each outlet (which was actually fairly common on vintage 1960's-ish residences).

 

[Karcen]

Yup....when the AC starts-up, two highly inductive devices are pulling power from the line, and generating a counter-electromotive force--the compressor and the fan motor(s). This causes a "dip" in the voltage that you are seeing on the outlet that is on the same branch circuit as the AC unit.

Ideally, the AC should be on its own, dedicated circuit; and, if it is not, you are going to have no end of problems with computing equipment sharing the same branch circuit.

Same goes for things like refrigerators, dehumidifiers, freezers, refrigerated water coolers, and, interestingly enough, facsimile machines (if such dinosaurs still roam the Earth). Even other computers can cause you problems--especially if you don't have a safety ground wire wired to each outlet (which was actually fairly common on vintage 1960's-ish residences).

I think it is just my computer the AC and bathroom lights that share the circuit and no other problems have emerged for anything else could the 1000 volt draw just be to much while a smaller pay would be better as I used to on a diffrent pc never encounter this.

 

[Karcen]

As for grounding we have that from when it was built or moved long before we moved in by my grand father and uncles there has just been no major wire overhaul.

 

[AllanGH]

You asked, and I gave you the facts.

Computers should never be on the same circuit with inductive loads, no matter how much power the computer draws.

 

[Karcen]

Okay thanks

 

[Karcen]

After looking into the circit breakers my computer us not on the same one. Still this only happens when the AC comes on so could the AC be drawing to much power for a shirt time as the lights do flicker when it starts.

 

[CountMike]

After looking into the circit breakers my computer us not on the same one. Still this only happens when the AC comes on so could the AC be drawing to much power for a shirt time as the lights do flicker when it starts.

That's already a sign of inadequate power going to house but possibly also too thin wires/cables leading to AC and other high amperage devices.
Single or 3 phase power coming in ?

 

[Karcen]

That's already a sign inadequate power going to house but also too thin wires/cables leading to AC and other high amperage devices.

Always suspected such well just have to live with it through the summer I guess

 

[AllanGH]

Single or 3 phase power coming in ?

If it's a single-family residence, of that vintage, in the USA, it's single-phase, 100A or 200A, 220V service entrance; with grounding likely to a cold water pipe, instead of a driven ground rod, unless that aspect has been remediated. (It is possible that the service entrance is 110V, instead of 220V, but that's extremely rare for 2-bedroom+ RDUs.)

Always suspected such well just have to live with it through the summer I guess

Just make certain that you have a good-quality, adequately-sized, UPS protecting the computer....at least the computer won't suffer extensively from the power transitions.

 

[Karcen]

Actually it is just a one bedroom as it used to be a small restaurant abd the big room has been cut in half. Also yeah I have a back up power supply with surge and drown out portection so should be good