EOL resistors

[barninks]

Im not massively experienced in fire alarms... But can you use one end of line resistor on a different brand of circuit? Currently we're using a kentech board and only have esp resistors to hand? Can I use those. I presume they are no different to any other brand.

 

[Strima]

What does the manufacturer say? Could well be different resistances so may show a fault?

 

[Dabbers]

You will need to find out the resistance required by that panel there will be a torrerance as long as you are in that bracket it should be fine? I take it that its a conventional system not a bi wire

 

[telectrix]

not alleol devices are resistors. some are capacitors. but as aboveif the same value then no problem.

 

[Stevetheaviato]

Im not massively experienced in fire alarms... But can you use one end of line resistor on a different brand of circuit? Currently we're using a kentech board and only have esp resistors to hand? Can I use those. I presume they are no different to any other brand.

Lots of dfferent resistors out there , sometimes you get lucky and the panel will accept the EOL , But in my expericence try and get the same.... p.s check around and inside the panel on every job ( you find spares )

 

[davesparks]

Just get some resistors of the appropriate value from RS, you can usually get hundreds for a couple of pounds.

 

[Vortigern]

eol devices are resistors. some are capacitors.

Interesting. I did not know that haven't heard of it before. Why a capacitor. I can see the reasoning of monitoring an alarm circuit with a resistor at the end, just got my head around that, now thinking of how a capacitor does the same job and how the PCB sees the capacitor on the circuit and what happens in the case a short anywhere on the circuit and so on. Might get a belt off the capacitor when testing?

 

[davesparks]

I can see the reasoning of monitoring an alarm circuit with a resistor at the end, just got my head around that,

I don't know much about fire alarms so don't know if this applies but in other systems that use digital data signals you sometimes need a resistor at the end of the line to stop signal reflections corrupting the data.

 

[telectrix]

Interesting. I did not know that haven't heard of it before. Why a capacitor. I can see the reasoning of monitoring an alarm circuit with a resistor at the end, just got my head around that, now thinking of how a capacitor does the same job and how the PCB sees the capacitor on the circuit and what happens in the case a short anywhere on the circuit and so on. Might get a belt off the capacitor when testing?

doubtyou'd get a belt. theyare tichy little things, in a little sealed pod. some may even be a R/C network.

 

[westward10]

They both essentially do the same thing. An EOL resistor provides a constant resistance on the loop which the control panel monitors for change. EOL capacitors are charged and discharged by the control panel, upon discharge the control panel can monitor the circuit resistance.