Accenta G4 blowing a fuse

[Frustrated Puma User]

I have an Accenta G4 mini panel running 4 PIR's, 1 PA button, 2 sets of door contacts and 2 bell boxes which are in SAB mode. I installed this system in December last year and it has been working fine up until about 1 month ago.

Upon going to set the system under Program 1 which is the normally used daytime program, the LCD RKP showed

'Setting Fault - Hall'

This is Zone 2 which is a PIR.

This was an intermittent issue for a day or so, and then I noticed that all the PIR's had no power to them. I placed the system into Engineer mode and then opened the panel.

I duly powered down the system and removed the battery power, which correctly caused the external sounders to activate. I then replaced the 13v 'Speaker' fuse (F4) and re-applied mains power to the system. Upon doing so, I visibly saw fuse F4 blow immediately. This subsequently happened with 4 different fuses each time I tried replacing it so I am pretty sure that there must be a short somewhere.

Next I opened up the PIR on Zone 2 and physically checked the wiring - none of the cores are touching each other, and there are no strands of stray wire bridging any connections. I then checked the PIR in Zone 3 and it too checked out OK (I have not yet checked the PIR's in Zones 4 and 5). I also checked all of the connections in the panel and again, none of them are touching one another and are not bridged in any way.

In both PIR's that I have checked so far, there appears to be power to every terminal even though fuse F4 is blown. (When I insert a voltage test screwdriver into the screws on each terminal in the PIR, it lights up).

I have used the same screwdriver on both ends of each fuse in the panel and it lights up when applied to them (with the exception of fuse F4, which is visibly blown and only lights the tester up at one end and not the other). The other two fuses appear visibly intact.


I do not have a meter so cannot check for voltages, So my plan is to check the other PIR's and cabling for any visible signs of damage or shorting, but failing that I cannot think of a better way to isolate the cause of the fault. Someone suggested replacing fuse F1 but I have not done so.

I can set the panel on Program 2 (which is used for night-time, and omits all the PIR's and just leaves the E/E and back door zones and PA active). The system works fine on this, and the external sounders also work fine either when the system goes into full alarm, or when all power is removed, or when the PA button is used, so I am at a bit of a loss as to what may be causing this fault.

If you can offer any advice as to what you think it may be, or better ways to isolate the fault I would greatly appreciate it.

Thank you for taking the time to read this long post.

Gary

 

[sparkymarka]

Silly question have you tried disconnecting the panel speaker ? As a short on this will blow the fuse ....and they do go short circuit ....remove one leg of speaker then replace fuse.

 

[Frustrated Puma User]

I have now also checked the remaining PIR's and their wiring is also in order.

@sparkymarka - not a silly question at all - I hadn't thought of disconnecting the speaker. I will do that tomorrow and report back. Thank you.

 

[Frustrated Puma User]

I just went and checked and the panel does not have a speaker fitted - the RKP acts as the internal sounder.

I did notice that after I had checked the other two PIR's and closed them again, the RKP still showed '2: Setting Fault - Hall' upon trying to set Program 1.

I tried setting Program 1 two more times and the 3rd time the RKP did not report a fault and allowed Program 1 to set (even though fuse F4 is blown and there is seemingly no power to the detectors).

 

[sparkymarka]

Is there anything connected in the speaker terminals in the panel ( not keypad ) also check for shorts from 0v to all alarm inputs ( remove from panel ) and tamper loop to 12+ also remove from panel.