One of my guys put his multimeter on the battery terminals during testing, unfortunately had his lead still in the 10A side!!!! This caused the loop to go down and giving no voltage reading on the B side and a high 34+ reading on the A side. with some missing devices and loop integrity fault.

The PCB was replaced (Hochiki protocol) early this morning however now with higher voltage reading on both sides (A&B) no missing devices reported but the system still bringing up a loop integrity fault... I just want to check whether this is a case of a device has popped on the loop causing the integrity fault?

 

I did not have any access to all detection areas today to fault find.

 

Any opinions welcome?

whoops...

 

1st I'd link loop at the pcb & check the new controls,

if the fault reappears when the loop is put back on the panel, I'd look 1st at the devices which contain isolators,

 

good luck

Cheers, I'll have to hope the installers put isolators in the field.. I actually have doubts over this.

Do you have any I/O units on the loop?

they have built in isolators (Hochiki)

I thought all the new Hochiki MCP’s do as well? (They may not but the ones I’ve ordered do)

nope no I/O units only 26 devices on loop. 4 MCPs this system probably installed 2014 not sure if the MCPs have isolators in those ones.

reverse the loop?

Thanks guys...

James why reverse the loop? Just spoken with Ctec and Hochiki. Hochiki say remove devices 1 by one and reset till it clears. Ctec say make a clean start, loop learn 1 side then loop learn the other side.

Hopefully only 1 detector is causing the problem 

Reversing the loop is what C-Tech have asked also, so where there is an “open circuit” you can learn up to a certain point (say the 11th device) then swap the loop cables around and learn the loop from the other direction to see where it stops (say up to 12) you would then know that 11 or 12 or both were the culprit.

 

let us know how you get on

Sure I get that and thanks however at the moment the panel is not showing any missing devices nor open circuits nor short circuits to either A or B side of the loop. So its a bit annoying having an integrity fault.. I guess thats just Ctec low tech way of saying something is feked 

 

Integrity fault IS and open circuit on the loop (C-Tec speak)

 

As above, spin the loop and see how far around it gets, it should stop at the break. It’s probably a busted isolator, hence you don’t have any missing devices. Alternatively, the XFP has a ‘blink device LED’ function, you can blink them from end A or end B. Wherever they stop blinking will be after the O/C.