Any experts out there on public address systems

[billy the kid]

Cutting a long story short...
I live in a block of units with a p.a. system which is basically used for fire warnings etc..
Mine has been coming on for a week in the middle of the night. No announcement, just a humming noise for 30 seconds
and then it turns off..just enough to wake me up.
Enquires of the building manager have produced nothing except the replacement of the speaker in my unit.
The suggestion is that "something" in the building is being turned on at exactly the same time every night and
tripping my speaker on....not happening in any other unit in the complex.
I think its bullshit...I think someone is waking me up deliberately....am I being paranoid....
Any thoughts from any experts out there....been coming on for a week....

[sprintcyclist]

Not sure, possibly a bad earth. An earth hum/ ground loop.
If you have 2 earth points with a voltage between then, it can cause a current flow and a hum.

I am guessing here.
Has it been dry there?

[billy the kid]

Thanx for your reply sprint....yes its been dry up here...
When the pa system comes on for the announcement of a test of the fire alarm system, I can hear the
pa system come on and immediately the announcement is made.
When the pa system comes on at night there is a slight pause and then the humming starts..
Its almost as though the system is turned on but the microphone is yet to be switched on as there is no hum
when the tests occur...there was a test a few days ago...several days after this problem occurred and afer I reported it...
My suggestion to management was for the speaker in my pa system to be disconnected, but they wont do that as it contravenes
fire regulations..I don't see an answer if it continues excepting that I disconnect it myself...

[Black Orchid]

The onus should be on them to keep the fire alarm system in optimum condition. If it's faulty they need to get someone out to test it. I thought it was a legal requirement that they have to do that on a regular basis anyway.

Take it to the Body Corporate?

[billy the kid]

They test the pa system regularly...I contacted the body corporate and they handballed it to
resort management....splitting hairs they are..

[sprintcyclist]

They test the pa system regularly...I contacted the body corporate and they handballed it to
resort management....splitting hairs they are..

Its hard with those intermittent faults. We deal with faults at work and intermittent ones are bad.
Try to stay focussed on the problem, not apportioning blame on who should fix it.

Keep a register of when it comes on.
Maybe the timing coincides with offpeak water heating coming on ?
Maybe it is interference from a local HAM radio operator or large local power draw. Trains ?
Maybe find the local earthing point and put a few buckets of water on it ?
We are getting desperate here and clutching at straws.

[billy the kid]

They test the pa system regularly...I contacted the body corporate and they handballed it to
resort management....splitting hairs they are..

Its hard with those intermittent faults. We deal with faults at work and intermittent ones are bad.
Try to stay focussed on the problem, not apportioning blame on who should fix it.

Keep a register of when it comes on.
Maybe the timing coincides with offpeak water heating coming on ?
Maybe it is interference from a local HAM radio operator or large local power draw. Trains ?
Maybe find the local earthing point and put a few buckets of water on it ?
We are getting desperate here and clutching at straws.

Thanx for your interest sprint...and BO...
The latest is that for four days this week there was no noise...interesting as the guy upstairs
may have been away as I didn't hear his loud tv on for that period...it comes on between 5 and 6 when he watches
"The Big Bang Theory"....then surprise surprise, last nite on comes the p.a. system at ...you guessed it...1.40am (and the tv was on again about 6pm....)
The Management team has contacted me and stated that their only obligation is to check the reliability of the p.a. system
which they did last Friday, and it was decided that the noise was not coming from my unit, but possibly caused by triggering of the system from the unit above me...…)
As I am not in the rental pool, nor is the occupant up above, they cannot assist. They say it is up to the body
corporate, which is as I expected.
I am awaiting now for the body corporate to contact old mate up above, who apparently has numerous health
aid apparatus in his unit...
The humorous part is that I just got a bill for body corporate fees...needless to say that wont be paid
any time soon.....
Stay tuned...yawn yawn...for the next exciting episode...names, place names and dates have been changed
to protect the innocent.....
God I must be bored to post this crap.....

[sprintcyclist]

That is a hard one Billy.

Unlikely it is linked to the neighbours TV, given the time difference between noise and TV on.
Wonder if he tapes something at that hour?
Wonder if some of his health aid devices charge or come active at that hour?

It is a puzzler.