Should I unplug my electronics?

[Aisengard]

I'm leaving my apartment for about two months. Should I unplug all my expensive electronics? I was told that this leaves them susceptible to damage if there's a lightning strike on the building, being that they'd be ungrounded.

I know I can save a little bit on electricity if I do this, but is it worth the risk?

 

[zerogear]

uh.. unplugging them leaves them susceptible to damage....? First time I've heard about it, unless your entire apartment is made of metal. Wouldn't fire be more of a risk if there was an actual lightning strike on the building?

 

[FishAk]

They are only susceptible to damage while plugged in. Lightning will follow the ground path to... ahm ... ground, bypassing anything not plugged in.

 

[RavenSEAL]

Just make sure you leave the power cords off ground level...that is all.

 

[corkyg]

Wheneever I go on a trip, I unplug all sensitive electronics, including myby home theater LCD. If they are3 no plugged in there's no way they can be damaged. Somebody misunderstood something. This is especially true here in Tucson during the summer monsoon season. I took a direct hit once by lightning. Destroyed my security system panel. Insurance replaced it. Zero damage to computers. They were not plugged in.

 

[fffblackmage]

When I was living in a dorm, everyone would be instructed to unplug everything when leaving for winter break. The reason is that power is shut off to the dorms. When they flip the power back on, there's a surge of electricity running back into the building, which would possibly damage electronics.

Same idea for the lightning strikes. You want things unplugged. Voltage spikes in the electric grid is baaad.

 

[Aisengard]

Okay thanks all. I guess I was under the impression that huge surges going through cables in your walls would generate some powerful electric fields...but thinking about it, I now realize that they would be magnetic fields instead, and they probably wouldn't have all that much reach *blush*.

 

[betasub]

I took a direct hit once by lightning.

... and lived to tell the tale. Any lasting bodily damage?

 

[Mark R]

When I was living in a dorm, everyone would be instructed to unplug everything when leaving for winter break. The reason is that power is shut off to the dorms. When they flip the power back on, there's a surge of electricity running back into the building, which would possibly damage electronics.

It's not really to protect the electronics - but to protect the building's wiring.

When many types of electronic devices are plugged in, they take a huge surge of power as they charge up their energy reservoir capacitors. It is the energy stored in these that allows PCs to withstand a short (e.g. 1/5 second interruption of power). Normally, plugging one or 2 devices in simultaneously isn't a problem - they may take a brief surge of 80 A each - for a total surge of 160 A - which will be ignored by most circuit breakers and fuses.

However, when you have a whole load of electronics - e.g. 50 computers in a lab - then things can quickly get out of hand.

At high school we had a computer lab with about 50 computers in it. I happened to see the electrical panel - and the lab computers had their own panel, separate to everything else in the building - with about 1 breaker for every 4 computers. Anyway, one afternoon I was supervising the lab, and things started getting out of hand - everyone decided to have a massive LAN gaming fest when I was trying to lock up. So I went to the panel and flipped the main switch. The room was plunged into silence, and everyone left.
Then, just before I went to leave and lock-up, I turned the main switch back on. There was a brief buzzing noise from the comps in the lab - and a snap and flash, as several breakers in the panel tripped off - and then the whole room and neigboring corridor was plunged into darkness.

I turned all the breakers back on, but nada.

While the electricians putting in the panel, had thought about the power surges and put only about 4 comps on each breaker - so that the breakers wouldn't trip (a few still did) - the hadn't thought about the effects of switching on the entire lab in one go. The surge was so huge that it blew out the main fuse for the entire wing of the building. Boy, was I in trouble for that.

 

[Modelworks]

Unplug everything from the wall outlets and make sure to also disconnect any cable tv lines and phone lines too.

 

[corkyg]

... and lived to tell the tale. Any lasting bodily damage?

Touche!

 

[westom]

Okay thanks all. I guess I was under the impression that huge surges going through cables in your walls would generate some powerful electric fields...but thinking about it, I now realize that they would be magnetic fields instead,

Which is completely irrelevant to your question. Destructive surges seek earth ground. Either energy dissipates harmlessly outside the building. Or that energy is hunting for earth destructively via appliances. It is not about magnetic fields, electric field or voltage. It is all about the current - and the path that current finds to earth ground.

Early 20th Century ham radio operators would disconnect the antenna lead. Even put that lead inside a mason jar. And still suffer damage. Why did lightning strike (and damage) Ben Franklin's church steeples? Because even wood is an electrical conductor. Your answer always starts with "What is the shortest path electrically to earth?" Not any ground. Earth ground. In every case, protection is always about the path that a surge uses to obtain earth ground.

Nothing stops that surge. Nothing. The answer to your question is about what is the best connection to earth. That should be where power enters the building.

Power on does not create a destructive surge - even when a majority believe that myth only because speculation says it must be true. When power is restored, voltage is lower and slowly increasing due to so many appliances all demanding maximum current. A destructive power on surge is believed by a majority due to propaganda and due to the 'believer' not bothering to demand facts and numbers.

Sometimes appliances can fail - especially power strip surge protectors. And nobody is there to avert the resulting fire - as zerogear has noted. Reason why you would disconnect appliances.

How often are dimmer switches - a least robust electronic device - destroyed by power on surges? Never. You disconnect only to avert a potential fire. Most common fire threat are zip (lamp) cords, extension cords, and power strip protectors.

 

[pitz]

Sure, it can't hurt to unplug, but another reason is that many, if not most electronic devices these days draw electricity, even if they are turned 'off'. This electricity usage is wasteful.

For instance, most cars have built-in computers that control various aspects of the engine, steering, and other things such as the radios, airbags, etc. Even if engine is turned 'off, these systems are still running, drawing electricity from the battery. Hence, a modern car will exhaust its battery power in the span of days to a couple weeks, and will require a boost or a recharge to start up again.

Whereas, for instance, one of my older cars has almost zero draw when its shut down, because there is no ECU to operate, no phantom loads. So I can walk away from it at the airport for 2 months, come back, turn the key, and it just leaps to life.

 

[fffblackmage]

It's not really to protect the electronics - but to protect the building's wiring.
...

Ahhh, I see. Thanks for letting me know! Now I don't have to learn it the hard way. XD

 

[westom]

Ahhh, I see. Thanks for letting me know! Now I don't have to learn it the hard way. XD

The problem: statements are based only in observation and speculation. His conclusions are subjective; not tempered by how things work. So he casts blame using speculation; without fact and numbers. Knowledge only from observation is classic junk science.

House wiring is so massive that, how much current does it take to trip a 15 amp circuit breaker? 100 amps for a half second. Why so much current permitted on a 15 amp wire? Because those 100 amps do not harm that wire. Reality changes once we include numbers.

Power on means massive current drawn by things already turned on - ie refrigerator. Notice how a refrigerator damages household wires. Oh. It doesn't? His only subjective conclusions said it must.

Power restoration to 50 powered off computers is near zero power. Four computers per breaker. That massive power on current is somewhere around 50 watts. 50 watts for a very short period. On a wire designed to provide 2400 watts continuously. With numbers, conclusions based only on speculation have no merit. Always mistrust any conclusion not tempered by numbers.

Power on is destructive when conclusions are based in observation and without basic electrical/electronics knowledge. Also called hearsay or urban myth.

 

[corkyg]

"Always mistrust any conclusion not tempered by numbers."

All generalizations are false including this one. A conclusion can be backed by numbers without stating them.

 

[westom]

A conclusion can be backed by numbers without stating them.

Trick to promoting lies - as demonstrated here - is to provide no numbers and to not first learn the numbers. Once numbers were applied, the myth dissolved. That myth only existed because the poster forgot to first learn the numbers - and therefore could not post any numbers.

No numbers? It is probably wild speculation or hearsay.

Power restoration does not cause those rumored problems.

 

[corkyg]

Again, it is a a valid point - but still an opinion, Totally agree with your last sentence.

 

[piasabird]

Well it would be nice if the equipment was situated in a way to make it easily unplugged. But that is not always the case. Often outlets are behind book cases and the like. Maybe with a little planning it would be easier. I dont often take off for very long. It might be nice to be able to afford some nice vacations. I would be worried about having my expensive stuff stolen while I was away.