Author Topic: hardwired interconected smoke detector  (Read 10267 times)

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toothy

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hardwired interconected smoke detector
« on: January 04, 2011, 12:45:54 AM »
Hello

Has anybody done any research on hardwired interconnected smoke detector power consumption?

I called Kidde the other day and they said that their model 2010 used 1 watt while just sitting there sensing. I don't see how a battery operated unit could last over a year at that rate.

Any insight would be appreciated.
Thanks
Wade

DamonHD

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Re: hardwired interconected smoke detector
« Reply #1 on: January 04, 2011, 01:27:08 AM »
You can be fairly sure that battery powered devices like that will have been engineered for low power consumption: for mains-powered ones maybe no one will have bothered.

To trya different tack maybe look for devices labelled as 'eco-friendly' or 'low-power' where there is again a reward for engineering for low power.

My whole primary Internet server only takes 4W!

Rgds

Damon

toothy

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Re: hardwired interconected smoke detector
« Reply #2 on: January 04, 2011, 01:36:25 AM »
I thought every new product for sale was "green, eco-friendly and low power".

Some folks call me a cynic!!!

I wish those terms weren't so abused, the truth would set us free.

thanks
Wade

Volvo farmer

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Re: hardwired interconected smoke detector
« Reply #3 on: January 04, 2011, 05:58:57 AM »
I do believe that no matter who manufactured the hard-wired smoke detector, the power usage is exactly zero watts when the breaker is turned off.  ;D

 
Less bark, more wag.

Opera House

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Re: hardwired interconected smoke detector
« Reply #4 on: January 04, 2011, 06:46:54 AM »
Seems to me something like a smoke detector will run about a month on battery.  Most devices don't rate actual power under 1W.  In low power devices more than half the power is wasted converting down to low power.  If it consumed 4ma from the battery it draws 5ma from the 120V line( .6 watt). I just took apart a 3W 120V LED.  It consumed 1/3W, 10% of the power in a resistor just to eliminate ghost lights when the switch is turned off. 

DanG

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Re: hardwired interconected smoke detector
« Reply #5 on: January 04, 2011, 10:43:59 AM »
Imagine the liability of distributing a life saving device being used anywhere by anyone all the time. My guess is 98.5% of that power usage is line noise-surge filtering.

kensue49

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Re: hardwired interconected smoke detector
« Reply #6 on: January 04, 2011, 01:53:28 PM »
They use a little power but will let you sleep better at night.
I know at one time they produced a interconnect smoke detector that had a battery backup.
Most AHJ require ac volt interconnected smoke detectors which seems a little narrow minded.
Kenneth

OperaHouse

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Re: hardwired interconected smoke detector
« Reply #7 on: January 04, 2011, 02:30:23 PM »
I happened to have one handy.  This one drew .045A, label rated it at .06A.  It had a capacitor and resistor as the line drop.  Most of the power was wasted in the zener.

hydrosun

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Re: hardwired interconected smoke detector
« Reply #8 on: January 04, 2011, 04:52:38 PM »
I needed some interconnected smoke alarms for a few off grid house that had the inverter in standby search mode most of the time. I bypassed the large resistor at the input and ran them straight on 12 volts. The resistor was dropping and consuming the voltage from 120 to 12 volts.  If the system was 24 volts I paralleled with a smaller resistor to keep some voltage drop.  The inspector was happy with his testing of the interconnected smoke alarms.
Chris

nick1234

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Re: hardwired interconected smoke detector
« Reply #9 on: December 09, 2011, 09:05:50 PM »
smoke detectors are available in 12vdc 24vdc and 120vac with interconnection and i have seen 9 vdc +120vac also

bj

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Re: hardwired interconected smoke detector
« Reply #10 on: December 10, 2011, 05:51:58 AM »
   I was curious as well Wade.  When I built this house, I used the Kidde units, so before installing, I put the backup batteries in,
and left them on the floor until I got the drywall up.  Time about 3 weeks.  No low battery alarms.  Just a cheap 9V battery.
   So, although the drain may be more than the battery only ones, it's still not that much.
   
"Even a blind squirrel will find an acorn once in a while"
bj
Lamont AB Can.