fire alarm loop resistance test

[john1doherty]

hi just been asked by the fire alarm commissioning engineers to provide them with the loop resistance values of the loops i have wired for them in a large shared housing project, can anyone point me in the direction as to what i need to do to test this and what results i need to satisfy him ? this test is normally done by the fire alarm firms i have had commissioning for me in the past so i dont want to be caught out on this or look a ****.

cheers:crazy:

 

[Toonlad]

Pos to Pos in low ohms
screen to screen (earth conductor) in low ohms
Neg to Neg in kilohms (from this they can divide value of one device into total and get approx amount of devices fitted.

There are a couple more measurements taken also.

I am a little surprised that the fire commissioning guys are asking you to do this for them, as if i was commissioning this i would not accept your readings on my sheet. But hey everyone to there own Lol