Head removed monitoring in a Two-Wire conventional fire alarm system

[Benzerari]

Hi all;

The head removed in normal conventional fire alarm system is achieved through many ways either using active EOL or normal resistor EOL with diode fitted in the base of each detector. but the two wire system is completely a different case, it can not use any of the ordinary ways so how is it done then?

Thank you

Benzerari

[Benzerari]

Hi all;

Is there any one please who can give us a bit of light of how a twin wire conventional system is monitoring the head removal process?

and thank you in advance

Benzerari

[Graeme]

In the case of the Manufacturer that i use,the detector base has a module which monitors the cable going out and generates pulses if a detector is removed.

Compatable control panels recognise the pulses given and enter fault condition.

The bases are wired in parallel,so no loss of power occurs when a head is removed and the eol is a resistor.

[Benzerari]

In the case of the Manufacturer that i use,the detector base has a module which monitors the cable going out and generates pulses if a detector is removed.

Compatable control panels recognise the pulses given and enter fault condition.

The bases are wired in parallel,so no loss of power occurs when a head is removed and the eol is a resistor.

Thanks Graeme for this micro light, that is really helpful

Do you mean the module inside the base is short circuited or disbaled when the head is fitted?

also what kind of pulse does this module delivers, its amplitude is it some thing like +5Vdc above the existing 24Vdc of detection circuit or +5Vdc above 0Vdc.....etc ?

the other enquiry is that how that pulses are not affected when the voltage is reversed in fire condition of two-wire system?

[Graeme]

Hi Ben


just to save time see link

thanks

g

http://www.apollo-fire.co.uk/PDFs/PP2060%20AlarmSense%20Product%20Guide.pdf

[Benzerari]

Thanks Graeme for this macro light