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We lost power to an entire room about a week ago. All outlets and ceiling light are dead and no breakers were tripped. Unplugged everything in the room, reset all breakers anyway and checked the only GFCI in the house which is downstairs from the room in the kitchen. The GFCI outlet was not tripped but I still did the test and reset. Nothing. Scheduled appointment with electrician who will come next week.

Today I needed to use my printer which was in the dead room. Took it to the bedroom across the hall and plugged it into an unused outlet in the room. The light came on in the dead room, I checked all the outlets and they are working as well. Unplugged the printer and power to the room went out again. What would cause this and would it be safe to keep something plugged into that outlet until my electrician comes? Or could that cause more damage?

  1. the outlet that restored power is directly below the light switch in the working bedroom but does not require the switch to be on to work. It is the only outlet that restores power to the dead room
  2. when I plugged in the printer there is a slight flash (arc?) in the outlet
  3. the dead room and the working room closets are back to back. The restoring outlet is on the same wall as the closet
  • Give that socket a good sniff, you probably will smell burnt metal and plastic. Arcing's never good, something's busted in it. – Fiasco Labs Jan 11 '15 at 8:23
  • It's common to get a tiny bit of arcing when you plug in something that initially draws a very high current. Power supplies with rectifiers in front of a capacitor often do this, since the capacitor holds enough charge for there to be a bit of an arc as it charges up to AC peak voltage. Depending on the AC phase at the moment the connector got close enough, the arc could be larger or smaller. A power supply with an inductor between the line and capacitor would reduce arcing. – Peter Cordes Jan 11 '15 at 14:46
  • @PeterCordes - I was thinking more of hearing a sizzle inside the outlet electrical box as the item plugged in completes the circuit so the other sockets come live. Yes, it's common for contact arc on the plug blades themselves. – Fiasco Labs Jan 13 '15 at 3:01
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Most likely scenario is that all the devices in the "dead room" are daisy chain wired on the same circuit coming from the outlet that you plugged the printer into. That printer outlet is likely to have been wired up using the notoriously unreliable back stab connections on the outlet. One of the back stab connections has come loose and when you plug in the printer it torques the contact metal inside the outlet just enough to make the loose wire connect up again.

The loose wire in the back of the "printer outlet" could be the source of arcing and this can build up heat and maybe become a fire danger. It is wise to get this addressed as quickly as possible.

When the circuits are repaired make sure to have all the wires be secured by the side screws on the outlet. That will give you reliable connections for years to come.

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    Just a note that new outlets have a backside connector, but it is secured by a screw. (Unlike the old ones which were a spring.) It's fine to use it. – Ariel Jan 11 '15 at 5:21
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    @Ariel - I would have to call the the type of outlet that you refer to as a rear entry screw clamped outlet. Whilst the wires do enter from the rear of the fixture they are not the quick "stab it in" style. As near as I know it is still possible to find plenty of new outlets and switches with the crappy back stab style of wire connections. The worst ones are those that have two back stab holes side by side per terminal. – Michael Karas Jan 11 '15 at 12:43
  • The better suggestion, IMHO, is to re-tap the circuit and provide pig tails to supply the receptacle especially since it's in an entirely different room. Using devices as taps is just ill-advised. – ChiefTwoPencils Jan 12 '15 at 23:53
  • @ChiefTwoPencils Actually most of the devices I have seen that are used for pig tails seem to hold the wires less securely than either wrapping the wires around the screw or using the new "screw-actuated clamp" type outlets (where you have to tighten the screw to secure the wires). – Brad Gilbert Jan 13 '15 at 4:53
  • @BradGilbert, I'm not speaking about a device; just a properly twisted tap, a wire nut, and a length of wire to the device. I say that mainly for continuity of the circuit even while replacing any one device in the chain. – ChiefTwoPencils Jan 13 '15 at 5:18

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