Fire alarm loop testing

[Coco199]

Hi all

Just a quick one.

For a fire alarm loop addressable system. Fp200 1.5mm cpc 1.5mm

To obtain R1+R2 would you treat the "loop" as a radial in effect and link brown and earth in connector then tester on other leg.

Or would you treat it as a ring and figure of eight and can be tested at any point.?

Thankyou

 

[UNG]

Why do you need the R1 + R2 of the addressable loop

 

[timhoward]

It can be handy if trying to calculate length of loop to prove to manufacturer support you haven't gone mad.
In general IR testing is far more pertinent before comissioning.

 

[UNG]

It can be handy if trying to calculate length of loop to prove to manufacturer support you haven't gone mad.
In general IR testing is far more pertinent before comissioning.

As you say IR is more pertinent / important to identify any shorts or cable faults
A check of the resistance of each conductor loop will verify that all the connections good and will give a resistance to calculate the loop length don't see the point of the R1 + R2 it's not likely to carry any fault current