The fuse jumps when i turn my pc on

[jekylhyde]

Hi
The fuse jumps (at the main fuse board for my entire room) when i turn my pc on
the pc is connected to an ac splitter with a switch.
in my other room it didn't happened
in this room it did
BUT after i put the fuse switch at the main board up, its ok
so why it jumped? (i didn't turned off the ac splitter).

 

[InvalidError]

You probably have other stuff connected to the same circuit as your room, usually in rooms sharing the same walls, and when you turn on your PC, the inrush is enough to trip the breaker when that other stuff, whatever it might be, is running. In older constructions, it was common to have one breaker per wall running from one side of the house or apartment to the other.

As for why the breaker does not trip when you turn it back on, it could be because whatever extra loads on the circuit are on some form of delayed start or simply because the breaker has some time to cool down before you reset it and that gives just enough headroom on its thermal trip to accommodate your PC.

 

[AntonyLovric]

Is there anything else on the circuit? Small fridge, window air-conditioner, baseboard electric heater? There might be something else that sucks power from that breaker and the PC puts it 'over the top'. (15A?)

 

[jekylhyde]

i have a fan connected to the same ac aplitter (bacause its hot here... i want some wind sometimes).
BUT its off when i turn the pc on

 

[InvalidError]

The fan being off when you turn the PC on and it trips the breaker does not magically rule out the possibility of other stuff being connected to the same breaker circuit as your PC elsewhere in your room or shared walls with other rooms that might be enough to trip the breaker when you turn on your PC.

 

[jekylhyde]

so what should i do?
there is nothing else connected in the entire room.
thanks

 

[AntonyLovric]

The wiring in most houses is a little funny. The outlet you're plugging into could be on the same cct as the room on the other side of the wall --or-- the room below/above the one you're in.

If you're positive you are the only one on the cct and it's still popping, there is probably an issue with one of;

- the wall receptacle (oxidized or loose terminals)
- the power cable / bar
- the psu

Personally, I think there is something else on the cct. (Water tank / baseboard heater / fridge / hot tub).

 

[InvalidError]

Personally, I think there is something else on the cct. (Water tank / baseboard heater / fridge / hot tub).

Practically all of these require dedicated circuits by code. In the case of water tanks and heaters in NA, those are usually on 240V circuits and would necessarily be on different circuits from everything else on 120V. The tub would require a GFCI either in a separate dry location or the breaker box.

If the PC is on a GFCI or AFCI breaker, it could be that it puts out enough leakage or noise on the line during turn-on to trip the breaker.

 

[AntonyLovric]

I know that those things *should* be on separate circuits but that's not often the case. (I've seen plenty of 'home' wiring jobs.) You do make a good point about ground-fault and arc-fault breakers though. I don't think it's a ground fault, however I wouldn't be surprised if the room is on an arc-fault breaker and whenever the computer turns on, the inrush current trips the breaker. Once the caps are charged the inrush current it lower and won't trip the breaker again until the caps discharge (overnight when psu is in standby or off?)

 

[jekylhyde]

i switch off the ac splitter over the night
in the morning i turn it on
the fuse jumps
i turn the fuse up & all is ok
i don't know what to do

 

[InvalidError]

After the breaker has tripped, visit every other room around the one the PC is in and see where else has no power either before turning it back on. That should give you an idea of how much other stuff might be sharing the breaker with your PC.

In my apartment, bedrooms are split between three breakers: the east wall, the inner walls and the west wall. The east wall breaker spans two rooms and also powers everything in the bathroom. The west wall breaker powers one bedroom wall, everything in the living room and one outlet in the dining room. The inner walls breaker also powers the kitchen and hallway lights.

 

[jekylhyde]

this fuse if for 2 rooms but the other room has nothing conncted to the wall/ac.

 

[jekylhyde]

 

[InvalidError]

There isn't much else to add. If you are 100% certain there is nothing else on the circuit which could contribute to tripping the breaker whenever you turn your PC on, then the only thing left to blame is the PSU.

At this point, your options are:
1- live with it
2- stop completely turning off your PC (shut it down from Windows but leave the PSU connected with the switches on - the arcing from inrush current may be slowly burning your switch out, a new power strip might not be a bad idea)
3- add a surge protector that has some decent power line filtering in it (one that has a common-mode and differential-mode chokes in it) and hope it softens the inrush current enough to stop the breaker from tripping
4- get a better PSU if you have a low-quality unit that has no input filtering whatsoever

 

[jekylhyde]

buying a ups could be better than a surge protector?

 

[jsmithepa]

Since it doesn't happen with the other circuit, I would tend to blame it on the "jumping" circuit. Very simple, switch off that circuit, and go around probing what appliances/outlets does it turn off. Either it's being overloaded or something very wrong with the wiring.

 

[InvalidError]

buying a ups could be better than a surge protector?

That would depend on how good the line conditioning is compared to something like an isobar which has a common-mode choke and inductors to soften transients. In some UPSes, there is minimal conditioning while the load is on AC power since the UPS is in bypass mode - power goes straight from the line to outputs to minimize losses.