Good morning all,
Our mxl siemens fire panels displays as trouble UL REQUIREMENT NOT USED AUDIBLE LOOP CIRCUIT OPEN, and I don’t know where the problem comes from, yet all our materials are UL listed and all devices work fine even the EOL is ok. if anyone could help me i would be very happy. thank you
what class is the NAC and which NAC does the trouble originate from?
thank you for your answer, the NAC is in class B and the problem comes from the audible circuit i think (output devices = 7 strobe horn light with the last one EOL resistance 2.2 kOhm)
this is what appears on the panel
does the NAC loop back to the panel after the ELR?
No the loop doesn’t back to the panel after EOL !
that’s what’s causing the trouble, you’re using a class A NAC as a class B, there should be 2 terminals next to where the nac is where you can connect the loop back, I can show you where if you send a photo of the NAC terminals
Nop i said that after the last device with the EOL the circuit is not coming back to the panel so as i know thats a Class B system right ? I have also a minus ground fault to my MMB card without any other cable so maybe it’s the card problem. Sorry for my english hope you understand !
I think the problem is that it should be wired as class A, not Class B
Which would be why it says “UL REQUIREMENT-NOT USED”
But you should probably try replacing the card
