Are shunt & EOL resistors common these days?

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PaulUszak

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The alarm sticky for this forum mentions them. Many websites mention selling contacts and detectors featuring them. It would seem that their usage is common.

The first four control panels out of the blue I've looked at (TS500, Veritas 8, ADE G4 and Menvier 510) do not seem to use any resistors as far as I can tell from their manuals. They seem to have a global tamper circuit that means you have to string together lots of detection zones with solder, blue tack or spit.

Considering that resistors facilitate more extensive monitoring of the zone wiring, I would have thought that all contemporary panels would use them. Granted that resistors require analogue voltage reading rather than a digital on /off, but most micro controllers have on chip ADCs these days.

Does anyone actually use shunt & EOL resistors?
 
Most professional panels are EOL some more basic small systems are not. Some panels will accept both EOL & DP wiring formats. EOL is far more secure than DP therefore more common on modern mainstram systems.
 
when I worked in this industry, EOL were widely used, a mate still works in a Fire alarm service company, keeps me updated, many still have these EOL for monitoring S/C and Open line, however, technology has moved on to the extent each device now has a unique ID and addressable and intelligent panels register each device in use, and allocates its presence and location in its data base, if an event is registered it promptly displays its location, panels also tries to reset an activation before a full alert is given, if it fires up again within a given time it can go into local area evacuation, as oppose to a full building evacuation, a panel can be programmed to only sound local area sounders effecting that part of the building where detection first occurred, so a partial alert, using data from adjacent detectors, analysing overall situation, panel can decide to give out a total evacuation of the whole building, using combination of these one can muster a panel almost 100% reliable and 0% false alarms, and yet provide full protection to its occupants.
A false alarm has many implications, unnecessary building evacuation and
and its effect on its productivity and exposing occupants to unnecessary dangers in evacuation process. So modern processor driven panels are highly versatile and highly intelligent, so similarly if a device is pulled out or removed or becomes faulty, it signals back its status, or if the control panel stops receiving any communication from it when
polled, the control panel automatically assumes an open circuit fault on the device, any unused branches or loops still requires an EOL​
 
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If you are going to use global tamper, don't use solder, blu-tak or spit. Use a choc-block in the panel to daisychain the tampers, each terminal having two wires in it (on the same side). The first terminal has one side of the global tamper and one side of the Zone 1 tamper. The second terminal has the other Zone 1 tamper and the first Zone 2 tamper... (repeat) ...the last terminal has the other side of the last zone and the other global tamper.

By doing this, you have a better chance of finding a tamper fault (mouse-chewed cable?). You can use your multimeter, set to read voltage, across each zone's tamper connections in turn to find out which one has voltage and is, therefore, open circuit. Good luck if the fault is intermittant or on more than one zone!!

Given the choice, I would always use resistors (and would retrofit them, if possible, when taking over a system), ideally more than 1k ohms as long cable runs and/or tired connections and contacts can sometimes add a couple of hundred ohms to a circuit.
 
EightyTwo said:
tired connections and contacts can sometimes add a couple of hundred ohms to a circuit
Click to expand...
I found this a year ago. My roller garage door contact decided that open circuit was actually somewhere around 200Ω. I always believed that a reed relay was for ever.
 
EightyTwo said:
The first terminal has one side of the global tamper and one side of the Zone 1 tamper. The second terminal has the other Zone 1 tamper and the first Zone 2 tamper... (repeat) ...the last terminal has the other side of the last zone and the other global tamper.
Click to expand...

Like so?
tampers.jpg

I find it odd that the choc block isn't part of the panel. There's plenty of room for a larger PCB and a few square inches of fibre glass doesn't cost much, especially in the context of time is money.
 
Yes, like so.

You only need the choc block if you're wiring the global tamper in the panel. It is also possible to "daisy chain" zones (don't do it!!) and then the tampers would be linked in the detectors/contacts.
 
If you don't like it, get a different panel, there are dozens/hundreds out there. research first.
 
What !!!!!!!!
He's not having a tamper circuit is he ?
Also plenty of room in his panel for his relay and extra sounder/strobe mods?
 
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