heat detector compatibility question with Radionics panel

[gjertsen]

I have an old timey D8112 Radionics panel at my new house and want to
replace the original heat detectors and smoke detectors. I don't want
to
replace the security panel at this time given that it works OK.
Looking at the compatibility
charts for this (and the web site compatibility info at Bosch and
System Sensor)
I see that they list this info for smoke detectors but nothing about
compatibility
for heat detectors. Is it safe to assume that I won't have an issue
with
the heat dectectors from a particular vendor? (I have 7 2-wire heat
detectors and
a 4-wire smoke detector in one zone with a 12V line)
I suspect that is the case given that I currently have Edwards GS heat
detectors
installed. I'm leaning towards System Sensor detectors because it
appears to
be a challenge to find Bosch vendors online (and would use the same
vendor
for all the detectors).

I'd also like to add 3 smoke detectors (for bedrooms for a total of
11). Pubs indicate
that there is 10 detector limit for one zone with 2-wire alarms.
Not sure why a 4-wire was put on the
system for single smoke detector, but my reading indicates that I can
hook up more 4-wire alarms without
a limitation, so I wanted to confirm that adding 3 4-wire alarms hooked
up to the
original 4-wire would work fine (and allow me to have 11 detectors in
one zone).
I'd planned on letting someone else do this part, but having trouble
getting someone to
do the work without trying to sell me an upgraded Bosch/Radionics
security panel.

Thanks for any pointers.

 

[Robert L Bass]

I see that they list this info for smoke detectors

but nothing about compatibility for heat detectors.

Virtually any heat detector will work with that system. Heats have a dry contact output, like a light switch. When they detect too
much heat or, in the case of a rate-of-rise sensor, when the temperature is rising very rapidly, they close a circuit. The alarm
doesn't care what kind of device closes the circuit -- only that it has closed.

BTW, technically, the circuit is always closed. There's a resistor at the end of the circuit which allows a trickle of current to
flow all the time. If the current stops flowing due to a cut wire or a device being disconnected, the alarm system will emit a
"trouble" tone and/or notify the central monitoring station of the problem. When the detector senses fire the circuit is shorted,
allowing lots of current to flow. The alarm senses this and emits a fire alarm (strobes, siren, bell or buzzers, depending on
what's installed. If monitored a signal is sent to the station as well.

--

Regards,
Robert L Bass

=============================>
Bass Home Electronics
941-866-1100
4883 Fallcrest Circle
Sarasota · Florida · 34233
http://www.bassburglaralarms.com
=============================>

 

[nick markowitz]

Heat Detectors do not have to meet compatability requirements because they
draw no power and will work on any standard fire panel loop unlike bells
horns trobes smokes etc.

 

[Nomen Nescio]

gjertsen said:

I have an old timey D8112 Radionics panel at my new house and want to
replace the original heat detectors and smoke detectors. I don't want
to replace the security panel at this time given that it works OK.

As others have pointed out, heat detectors are just normally open switches,
and so there are no compatibility issues. Two-wire smokes draw power, and
create an alarm over the same wires that deliver power, hence the
compatibility concerns. System Sensor smokes will work fine, so long as
you don't use two wire smokes with internal sounders and expect them all to
sound at once.

However, your heat and smoke detectors should not be wired directly to the
8112. They should be wired to a D125 or D129 module, which is attached to
the side of the 8112 cabinet. The D125 is mandatory if you are using two
wire smokes. There is no reason you can't mix heat detectors and smokes on
the same zone, although you might want to know where the fire is.

Smoke detector reset is done from terminal 8, as I recall, and requires the
installation of an extra relay in order for the reset code, command-47, to
work. The relay plugs into the circuit board underneath the sheet metal
cover.

- badenov

 

[gjertsen]

Thanks for all of the helpful comments that everyone provided for a
novice in this area.
This will get me started on replacing the old
detectors, and with some additional digging (looking over the system
and
more reading), then I should be able to add the new smoke detectors to
the
bedrooms.

--Rob