Fire alarm

[the pict]

Hi All, should a sounder circuit be between 6&8 Ohms and detectors the same, even if it's done in 1950' pyro, also should I get a difference in mA's on sounders and detectors between L&N L 2mA N .5mA, if I find a resistor in a head is that the end of line, I have a missing head with resistor in the holder is this a bypass or is it end of line sorry if this is a bit glib as I am having a mid life crisis,
Pict

 

[Jay Sparks]

Hi Pict,

Not sure about the testing side of it, as I normally leave that to the fire tech guys but yes, the resistor useually means E.O.L.

Jay

 

[telectrix]

if there's only 1 cable in the box, then it's EOL. sssimplesss

 

[the pict]

So in the holder with the missing head with the resistor if I link out the terminals for the head the "fault" should clear, any one know if the resistance of alarm cable "the red stuff" is the same as old pyro and are all heads standard
Pict

 

[telectrix]

different makes are different. if a head is removed, there's a diode across 2 teminals that fools the panel into thinking the head is still there, first thing i would check is the volts at the box. if it's a detector circuit, you should have 24V. if it's a sounder circuit, should only have volts when panel is in full fire alarm.

 

[the pict]

Thanks Tele in the holder with the missing head there is what I assume is the EOL resistor in a black encapsule but nothing else although the fault lights are general fault and sounder 1, it is a MAG 2 so I think I may get a new head and holder complete
Pict

 

[telectrix]

sounds like ( pun intended) that it's a sounder circuit. as i said, check d.c. volts at head to confirm. the eol device may be a mix of resistor/capacitor. if a pure resistor it will be generally between 1k and 6.8k ohms.

 

[the pict]

Do you mean at the sounder head for DC V or at the sounder panel terminals I suppose both would do no harm ??? I have ordered a new head and base and a call point as one had got water damage
Pict

 

[telectrix]

at the panel you should have permanent 24v d.c. on the zone terminals. same at each detector. for sounders, you need to put the panel into "fire", then check for 24v at sounders.

 

[the pict]

Thanks Tele normally I do'nt do these as you probably have guessed but its my pub landlord and I have done a load of work for him so I do'nt like to knock him back thanks for your patience
Devlin