Strange false alarms with smoke detectors

About 15 minutes ago, all the smoke alarms in my house went off at the same time. There was no smoke, fire, dust, or any logical explanation as to why all the alarms went off, let alone simulataneously.
10 minutes after the alarms went off, they suddenly stopped all. Then they started up again for a brief minute or two, and after that silence.
The alarms are hardwired, on their own circuit, and have battery backup. I did not notice any power surges or anything out of the ordinary that could explain this.
If the batteries were all to fail, the alarms would chirp, not go off. If the power was to fail or blip, the alarms would make a brief beep.
My first guess is an electrical spike; however the lights did not flicker or anything. It could be that the smoke detectors were on a separate phase from the lighting circuit, though.
Any ideas?
73,
Tim
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Update:
They went off again. However, I unplugged one from the house wiring and it did not go off, further convincing me this is wiring related.
But what exactly is going on?????
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After switching off the power at the fusebox the one alarm we still had connected to the circuit (now de-energized) went off.
???????????????????
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After switching off the power at the fusebox the one alarm we still had connected to the circuit (now de-energized) went off.
???????????????????
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On 2 Dec 2005 22:25:15 -0800, snipped-for-privacy@gmail.com wrote:

You DO have an electrical problem because your computer keeps posting messages twice !!!
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wrote:

My computer does that occasionally. Norton scans the message and then sometimes can't talk to Outlook and says the message hasn't been sent, and instructs me to re-send it. When I resend, it'll then send twice. Don't know if it's Norton or Billy Gates that has the flaw but somehow they don't speak to each other very well. I'd advise the OP to turn off e-mail scanning on his firewall and then see if it sends just once.
Bob
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Update:
They went off again. However, I unplugged one from the house wiring and it did not go off, further convincing me this is wiring related.
But what exactly is going on?????
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your interconnected smoke detectors have a hot-common-trigger hookup of 3 wires. when one thinks there's a fire it tells them all to sound. find the bad one and replace it.look up the make and model using google.com
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Also, some brands will have a flashing led to let you know which one "thinks" it is sensing smoke. You of course need to put on your ear plugs to hang around long enough to find it

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snipped-for-privacy@gmail.com wrote:

They all went off because they are designed to to make sure you hear them
I am going to guess that you have not recently replaced those batteries. If you replace them that will likely eliminate the problem, which will be back the next cold night.
--
Joseph Meehan

Dia duit
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