Turning on light turns off computer

[Hans L]

Hello:

Often when I turn on my office ceiling light, my wife's computer in her office (next door) reboots. Her monitors stays on.

My ceiling light is a power-saving light (one of those spiral bulbs ... CFL, here in America).

My wife has a UPS ("uninterruptible" power supply), so you would think ...

I am sure I can put acapacitor and a resistor over the light switch, but I have forgotten too much of what I learned as a telecommunications engineer a LOOOONG time ago, so I am asking for advice.

Thank you!

Hans L

[kalniel]

In they UK they'd be on separate circuits so this would be impossible. Don't know US regulations, slightly surprised they wouldn't have something similar, but yeah, long term better solution would be to put lighting on a separate circuit otherwise you're going to have problems every time a bulb goes.

If they are on separate circuits then you have a problem with your wiring somewhere, call an electrician.

Short term solution would be get a UPS that actually works.

[Hans L]

Kalniel, everything in both our offices are on the same circuit. Don't even know if it is possible to separate the computers and lights without going through walls etc.

My UPS also reacts often when the ligt is turned on, but it never affects the computer. O, as you say, the easiest way is probably to check out the UPS. Surge protector might not protect anymore.

Thanks,

Hans L

[Disturbedguy]

Kalniel, everything in both our offices are on the same circuit. Don't even know if it is possible to separate the computers and lights without going through walls etc.

Surely, they should be on different circuits? Sounds like some dodgy wiring somewhere...

[heXuser]

cheap bulbs can cause this also

Other thing you can do is: plug in one item at a time and test by switching the bulb on, to see which item is causing problems but I would try new bulb first to make sure its not the bulb

[Hans L]

Surely, they should be on different circuits? Sounds like some dodgy wiring somewhere...

It is only, Disturbedguy, that this house was built in 1963, and they had no reason then to put the ceiling lights in our two office and the wall outlets on different circuits. And, as I say, to put them on different circuits, while not impossible, would be rather difficult. I will check my wife's UPS and buy a new one if needed.

I will, of course, also replace the bulb in my ceiling lamp.

Regards,

Hans L

[Hans L]

cheap bulbs can cause this also

Other thing you can do is: plug in one item at a time and test by switching the bulb on, to see which item is causing problems but I would try new bulb first to make sure its not the bulb

Well, as I said, what I have is an energy-saving spiral bulb in my ceiling lamp (example: http://www.energybulbs.co.uk/product...g+Spiral+Bulbs). I will replace it with a similar bulb, and also with a regular bulb, and see what happens.

Since my UPS gets a hickup when I turn on my ceiling light, and my wife's UPS obviously does not protect here computer (surge protector not working), it is quite clear what happens – a surge.

It is funny – what normally happens is that a spark is generated in the switch when you turn OFF a light, so you could expect some sensitive electronics to get a hickup from that event, but, as I said, my problem is with turning ON the light.

I'll report back!

Hans L

[peterb]

A good UPS should protect against spikes and surges, as well as brownouts. Depending on the age of the UPS, you may need to replace the battery. However, that is only treating the symptoms, long term you need to find out why it is happening. My money would be on some sort of earth leakage, but I'm not completely familiar with US wiring standards.

IIRC some US installations have a 230 v centre tapped supply to give 230V for high power consumption appliances (washing machines and so on) and 115 for lighting and normal domestic appliances, so there could be a problem there. Probably better getting an electrician to sort it out.

[Hans L]

Peter, I will check the UPS on Wednesday (working outside Sun - Tue, since the temperatures and humidity makes this possible here in Cleveland, Ohio).

Had an electrician replace the entire circuit breaker box about three months ago (and he seemed competent, though fairly full of himself :-), but this thing with *my* UPS hickuping has gone on for much longer than that. My wife's computer rebooting (twice now in the last month) is new, though.

Come Wednesday, I'll begin investigating.

Regards,

Hans L

[MrBozack]

Fluorescent light fittings can do this, regardless of which circuit they're on. To my knowledge, there's no certain resolution.
In my last house, the kitchen tube used to trip the PC. I invested in a UPS and a £90 surge protector which didn't help. I changed the light fitting to a low voltage dichroic set. The problem vanished.

My present house was built 2 years ago - and we have similar issues. The boiler makes the amplifier cut-out for a second when the immersion activates.

[Hans L]

Fluorescent light fittings can do this, regardless of which circuit they're on. To my knowledge, there's no certain resolution.
In my last house, the kitchen tube used to trip the PC. I invested in a UPS and a £90 surge protector which didn't help. I changed the light fitting to a low voltage dichroic set. The problem vanished.

My present house was built 2 years ago - and we have similar issues. The boiler makes the amplifier cut-out for a second when the immersion activates.

Sad and glad to read your post, MrBozack :-)( Sad there is no certain solution, glad you found one, and sad you have the problem again.

As my lamp is a ceiling lamp, a reflector bulb would not do. When I was involved in ham radio in the old days, we used to put a capacitor and resistor (in series or in parallel, depending on the situation) over the contacts of a switch to take care of sparks. But if this interference happens inside the low-power bulbs, I don't know what can be done.

I think I will go onto the web and make a google search.

Regards,

Hans L

[GoNz0]

i would get the earth system in your house tested. if you have an outside ground rod it may be corroded

[Hans L]

i would get the earth system in your house tested. if you have an outside ground rod it may be corroded

That would not be a bad idea, GoNzO. I'll check what is used to ground the electrical system.

Regards/Hans L

[Thugonought]

That would not be a bad idea, GoNzO. I'll check what is used to ground the electrical system.

Regards/Hans L

This thread is 10 years old but here we are with me getting the same problem with the light switch turning off the computer black screen. It happens when I turn the light on as well as the miniture oven. I didn't initially get this problem occurring with either the light switch or the oven but it just started happening and now it's every time I flip the switch now. I don't have a UPS but want some advise on it please. I live in a rented unit in Sydney and getting the landlord to address this issue would be one massive uphill battle for me I am sure!

I should also add that it is really difficult to get the computer to switch back on. The motherboard light's up for a second and the fans spin for that second but it turns off like it's protecting it's self. I get around the problem by turning off the power supply at the back of the machine as to stop all power to the motherboard and components. It's about a 1 in 5 chance that I will get it to turn back on. Not sure if the getting it to turn back on problem is related to the turning off problem. your thoughts?

thanks