Building and Construction - Rewiring a Hardwired Smoke Detector WITH THE POWER ON

Author

Rewiring a Hardwired Smoke Detector WITH THE POWER ON

gobofraggle@gmail.com

2008-04-01, 5:25 pm

I have a hardwired smoke detector that is old and outdated, that I'd
like to switch with a new unit. The only problem is that I can't shut
off the power to the alarm before I disconnect it and reconnect the
new one. I'm going to have to do the take-down and installation while
the power is LIVE.

I live in a high-rise apartment building and the smoke detector is
powered not by my unit's individual power, but off of a line brought
in from a common hallway. There is no way to cut power to the smoke
detector without cutting power to all the lights in the common
hallway, which is impossible.

So, how can I safely (or as safely as possible) change this detector
with a new one? If I don't touch certain wires together, will I be
OK? What are the chances I would get shocked?

I know your first inclination will be to tell me to get the circuit
turned off or call an electrician, but please (at least
hypothetically) assume that neither of those options are possible.

Thanks.

Wayne Whitney

2008-04-01, 8:26 pm

On 2008-04-01, gobofraggle@gmail.com <gobofraggle@gmail.com> wrote:

> I'm going to have to do the take-down and installation while the
> power is LIVE. [. . .] So, how can I safely (or as safely as
> possible) change this detector with a new one?

You can't. Working LIVE has inherent risks, and unless you are
sufficiently experienced with electrical work, should not be done.

> I know your first inclination will be to tell me to get the circuit
> turned off or call an electrician, but please (at least
> hypothetically) assume that neither of those options are possible.

Call an electrician. I mean, you have to draw the line somewhere, and
working LIVE is a good place to draw the line. If for some reason
getting an electrician is currently impossible, then get yourself a
battery operated smoke detector until you can get an electrician.

Yours, Wayne

jloomis

2008-04-01, 9:25 pm

Not touching the ground, or the neutral or the hot at the same time........
Wear good gloves.......insulated ones........separate the wires one at a
time.
Use black tape to bend over the wire for temporary to keep it from flapping
into a grounded object.
I would tape the hot first........leave it alone.......
Then with gloves and such hook up the neutral and the ground....
Use a circuit tester to make sure these are neutral and ground and hot.....
I have done it many times......
I am a General Contractor, and do wire houses on occasion......
We have actually moved overhead service while hot.......
Don't tell anyone........shhhhhh
jloomis
<gobofraggle@gmail.com> wrote in message
news:c5741458-a98f-46c1-90b7-1e7fabb1bd23@k13g2000hse.googlegroups.com...
>I have a hardwired smoke detector that is old and outdated, that I'd
> like to switch with a new unit. The only problem is that I can't shut
> off the power to the alarm before I disconnect it and reconnect the
> new one. I'm going to have to do the take-down and installation while
> the power is LIVE.
>
> I live in a high-rise apartment building and the smoke detector is
> powered not by my unit's individual power, but off of a line brought
> in from a common hallway. There is no way to cut power to the smoke
> detector without cutting power to all the lights in the common
> hallway, which is impossible.
>
> So, how can I safely (or as safely as possible) change this detector
> with a new one? If I don't touch certain wires together, will I be
> OK? What are the chances I would get shocked?
>
> I know your first inclination will be to tell me to get the circuit
> turned off or call an electrician, but please (at least
> hypothetically) assume that neither of those options are possible.
>
> Thanks.

Glenn

2008-04-02, 1:25 pm

"jloomis" <jloomis@ocean.net> wrote in message
news:fsuo9a031i0@news3.newsguy.com...
> I would tape the hot first........leave it
> alone.......
> Then with gloves and such hook up the neutral and the
> ground....
> Use a circuit tester to make sure these are neutral
> and ground and hot.....

Good advice. Some screwball may have reversed
polarity. I have had that happen. It's a shocking
experience.

Roscoe P Pendoscoe

2008-04-03, 5:25 pm

On Tue, 1 Apr 2008 15:22:28 -0700 (PDT), gobofraggle@gmail.com wrote:

>I have a hardwired smoke detector that is old and outdated, that I'd
>like to switch with a new unit. The only problem is that I can't shut
>off the power to the alarm before I disconnect it and reconnect the
>new one. I'm going to have to do the take-down and installation while
>the power is LIVE.
>
>I live in a high-rise apartment building and the smoke detector is
>powered not by my unit's individual power, but off of a line brought
>in from a common hallway. There is no way to cut power to the smoke
>detector without cutting power to all the lights in the common
>hallway, which is impossible.
>
>So, how can I safely (or as safely as possible) change this detector
>with a new one? If I don't touch certain wires together, will I be
>OK? What are the chances I would get shocked?
>
>I know your first inclination will be to tell me to get the circuit
>turned off or call an electrician, but please (at least
>hypothetically) assume that neither of those options are possible.
>
>Thanks.

You may want to see if your smoke detector is interconnected and
otherwise connected to a main station that would require not just any
old off the shelf FIREX or KIDDE alarm.

There are no grounds connected to ANY smoke detector I have ever
installed in residential housing.

If you have determined you can use any smoke detector without screwing
up the system that may be in place just disconnect one wire at a time
and typically that would be the NEUTRAL (White) then the black (Hot).
If there is also a red wire or any other color other than black
connected to the RED wire on your existing smoke detector you have an
interconnected system.

I wouldn't think the polarity is reversed if this thing has been
functioning properly for who knows how long.

I would then ask your building super for advice........like What if I
wanted to............

Have fun, be careful.

Regards,

Roscoe

Knowledge is like money, the less you talk about it
the more people assume you have.

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