Re: Replacing Radionics with Vista 20P

[JoeRaisin <joeraisin2001@xxxxxxxxx>]

On 1/21/2011 12:26 PM, RockyTSquirrel wrote:
> Jim wouldn't the 4 conductor return as Joe was saying be the same as a
> class A so long as the resistor was in the cabinet of the control?
> (just asking)
>
> RTS
>

Not really.  With one break in the line, a class A circuit would still
be able to get an alarm signal from any detector on circuit.  The EOL in
the can will still result in losing any devices past the break.

It's just that we used to prewire complete circuits with four conductor
just in case something happened to our wire.





> "Jim Rojas" wrote in message news:7Mh_o.13$be.3@xxxxxxxxxxxxxxx
>
> Christopher Glaeser wrote:
>> I found the EOLRs. There is a small faceplate below the old Radionics,
>> so I opened it and found a rats nest where all the wires come together.
>> As best I can tell, the zones with multiple sensors are wired in
>> parallel just below the panel, and the 1K EOLR is also added just below
>> the panel. Doesn't this defeat the purpose of an EOLR? Isn't this really
>> just a BOLR? Also, if an EOLR is at the panel for a fire zone, is this
>> to CA code?
>>
>> Best,
>> Christopher
>>
>
> The EOL for a smoke alarm must be at the last device.
>
> If you are using 2 wire smokes, you can use 2 wires, then EOL at last
> smoke. All smokes must be daisy chained for proper supervision...
>
> 2 Wire Smokes
>
> Fire Zone + ---> + in + out ---> + in
> + out ---> + in + out ---> EOL
> Fire Zone - ---> - neg ---> - neg ---> - neg ---> EOL
>
>
> If you are using 4 wire smokes, the same is true with the addition of
> using a power supervision relay at the end of line. With 4 wire smokes,
> do not twist wires together, even though the are going on the same
> terminal. This provides better supervision against tampering.
>
> 4 Wire Smokes
>
> Fire Zone + ---> C ---> C ------------------------------> EOL
> Fire Zone - ---> NO ---> NO ---> Relay Closed Contacts ---> EOL
> Power + ---> + ---> + ---> Relay coil
> Power - ---> - ---> - ---> Relay coil
>
> Jim Rojas
> Technical Manuals Online!
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