Compression damage, I can go for that.

Maybe not from the install, but in light of certain questions raised it is not one to be discounted.

I would check logs and ask (like the truth would be told if it was damage by others) if any works have been undertaken as well.

Here is a good example of knowing the job and cable runs.

This is public is it not?

Not very encouraging is it?

Id assume that would trip fused, thermal fuses etc. Looks like an overload total output not a single fault like overload. Bridge rec could be damaged. Is there any board discolouration or a silly hot regulator?

Just wanted say thanks for all the useful comments (some not so useful, seems like some guys like to blow there own horns on here!)

Called back out to site today and installed a new transformer and checked the log it came back with a false alarm from a detector connected to an expander then a mains fail, I have3 expanders installed- 2 next to the panel and one 30 metres away', the false alarm came from the detector connected to the expander furthest away so I tested tested the cable to the expander and the faulty detector and found a short on the expander cable, (builders had damaged the cable) I did not have time to replace the cable so I disconnected the expander and expander cable, I'm hoping this will resolve the problem, I will be calling back tomorrow to replace the cable and expander,

The weird thing is the alarm never threw up any faults from the attached expander!

Why would ANY external wiring blow a transformer?

I would have thought the fuses would blow before the transformer.

Try all these tests

Alarm Tests.pdf

Id assume that would trip fused, thermal fuses etc. Looks like an overload total output not a single fault like overload. Bridge rec could be damaged. Is there any board discolouration or a silly hot regulator?

Everyone's last guess was pretty much on the mark so I will offer another not very helpful comment based on my exsperience of people with the inability to diagnose and guess that there was a bucket full of blown glass fuses of varying sizes floating around the panel

5 amp fuse in the end?

Nobody blowing horns here, just saying there are certain tests to be done in these circumstances.

Which seem to have been not done/ignored/not known about.

You have done AS suggested and "hopefully" now found the "fault".

Seems to be a pattern to your diagnosis, a thank you rather than a cryptic answer would have been the better reply.

As for the fault not showing, it can depend on how it was wired, another thing you may find you resolve when replacing and maybe following the wiring diagram this time.

Nothing adds up here. A short on the alm side would do nothing, a short on the power side would blow a fuse. The fault hasnt been found yet imo

I agree with James maybe the short on the expander has damaged the PSU circuit (bridge rec, regulator etc) and this is causing the transformer to die.

Time will tell.

Just wanted say thanks for all the useful comments (some not so useful, seems like some guys like to blow there own horns on here!)

Called back out to site today and installed a new transformer and checked the log it came back with a false alarm from a detector connected to an expander then a mains fail, I have3 expanders installed- 2 next to the panel and one 30 metres away', the false alarm came from the detector connected to the expander furthest away so I tested tested the cable to the expander and the faulty detector and found a short on the expander cable, (builders had damaged the cable) I did not have time to replace the cable so I disconnected the expander and expander cable, I'm hoping this will resolve the problem, I will be calling back tomorrow to replace the cable and expander,

The weird thing is the alarm never threw up any faults from the attached expander!

I will take a bow, I guessed expander or cable.

Poor product to blow the tranny though, can't see that happening on a castle product.

Edited October 29, 201213 yr by alterEGO