Discuss Fire alarm what is this? in the Security Alarms, Door Entry and CCTV (Public) area at ElectriciansForums.net

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Called to a hotel where the spark doing a refit took down something and then said that he had no idea what it was so they better call someone else.
I then got called in and I have no idea what it is, apsrt from its the end of line on the fire alrm circuit.
Fire alarm what is this? {filename} | ElectriciansForums.net
Fire alarm what is this? {filename} | ElectriciansForums.net
Fire alarm what is this? {filename} | ElectriciansForums.net

Fire alarm what is this? WhatsApp Image 2019-02-13 at 12.21.03 - EletriciansForums.net

Fire alarm what is this? WhatsApp Image 2019-02-13 at 12.21.04 - EletriciansForums.net

Fire alarm what is this? WhatsApp Image 2019-02-13 at 12.21.05 - EletriciansForums.net
 
Looks like an old heat detector. It has been painted, if you scratch some off you will probably find the dome is metal.
 
I see it was manufactured by AFA (Associated Fire Alarms) now AFA Minerva.
 
Old heat detector (not been made for around 20yrs plus).If you are replacing it make sure you check the cable as it could be 30-40 years old.
 
Rs 485 end of line resistor should have 3 resistors no? Manchester bus powered has 1 resistor and one capacitor. What's this system?
 
VERY late to the party with this.
It's a "Life Saver" heat detector; initially manufactured and installed by Minerva Fire Defence and then continued to be installed when they became AFA-Minerva (when EMI merged together).
There is a bi-metallic strip inside, the devices are normally open circuit, when heated up, the bi-metallic strip shorts the alarm circuit to sound it. Some had 220k resistors in.
Most of the systems these were installed on were the CT1 and CT6 panels - these operated from batteries, and powered an inverter.
The Zone pair had 220v DC on it (not 24v as most people would assume).
 

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