Hi, DIYers!
Joe from AlarmGrid.
And today we're going to talk about
whether you should use a two-wire or a four-wire smoke
detector.
Today, I have a two-wire smoke detector,
but the four-wire smoke detector of this particular model,
looks exactly the same.
And they do the same thing.
So why use a two-wire or a four-wire?
The main difference between the two-wire
and the four-wire smoke detector is
that one works with two-wires and one works with four-wires.
A two-wire smoke detector has a pair
of wires going back and connecting to the alarm system.
These two wires handle power and data for the smoke detector.
On a four-wire smoke detector, this is broken up.
So one pair is going to be for the data connection,
and one pair is going to be for the power connection.
Either of these smoke detectors actually
need their power to be cut when an alarm occurs
so that they can reset.
On a two-wire smoke detector, if you
have it connected to a VISTA alarm system,
zone 1 on that VISTA alarm system
has a power reset feature.
That means is that when this two-wire smoke is connected
to that alarm system, after an alarm occurs and the user
disarms the alarm system, that's going to temporarily
cut power to the smoke detector so that it can reset.
It's a really nice aspect of a two-wire smoke with a VISTA
system or any other system that does that particular function.
A four-wire smoke detector has two-wires
dedicated for its power and two-wires for its data.
What that lets you do is gives you a little more flexibility
for installation, because you can install it
on a system that doesn't have a dedicated power reset
terminal like a VISTA.
You could wire up a smoke detector
to a relay and a power supply, so that the power could be cut,
whatever particular alarm system goes into alarm,
so that the smoke detector can reset.
So as you can see, depending on what installation
you're going to put the smoke detector into
could change whether you're going
to use a two-wire smoke detector or a four-wire smoke detector.
If you have a wireless system, also, there's
an even better chance that you're not
going to use a wired smoke detector at all,
and you just put a wireless one up.
If you do have a VISTA system or a system
with a power reset function on it,
though, the two-wire smoke is going
to be easier to install as you just
have to get a pair of wires from the alarm system
to the smoke detector, wire it up, then you're good to go.
On the VISTA system, as an example,
you can install more than one two-wire smoke
onto that single terminal.
All you have to do is wire them up in parallel,
put a resistor at one of the smokes
to be that end-of-line resistor.
Ideally, you want to put it on the one furthest
away from the panel so that the whole line is supervised,
and you'll be good to go.
Now let's talk about power supervision
on the four-wire smoke.
On a four-wire smoke, we have two connections
for data, two connections for power.
Our data connection is likely going back to our alarm panel
to an open zone.
And our power connection's likely
going back to either the alarm panels, power output,
or an auxiliary power supply.
Most smoke detectors are normally open,
so if something happens to the power connection
to the smoke detector, there's nothing in the smoke detector
that's going to tell us that something's
wrong with the device.
What you can do to remedy this is install a power
of supervision relay module.
And if you have questions about installing these
or how to set it up, check our website out or give us
a call, because it can be tricky and a little confusing.
Basically, what this does is that it sits
and it monitors the power connection
to the smoke detector.
If something goes wrong with the power,
the relay is going to open and put the smoke into trouble
telling you or us that something happened to the power coming
to the smoke detector.
This is a really helpful device, especially
if you have four-wire smokes installed,
because you do want to know if they have power applied to them
or not.
You just have to make sure that the smoke detectors that you
do install don't exceed the maximum amount
that the panel can handle.
And if you check the panel's installation manual,
it will tell you what it can do or not.
So again, if you do have any questions about whether or not
you should use a two-wire or four-wire smoke, what
works for your system, or really if you should go wireless
in general, feel free to give us a call at 888-818-7728.
Send us an email to support@alarmgrid.com, or head
to our website, www.alarmgrid.com.
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Thanks for watching, and have a great day.