Yale HSA6400 possible siren issue

[jjdiy7]

I need some advice.

I've had this alarm installed for a few years now and have had no issues so far, but during our last holiday our neighbours claim the siren was on and sounding even though there is no record in the logs for any of those days.

Is it possible for the siren to sound and not leave any traces in the logs? I understand the siren has built-in jamming detection, which can cause tamper condition, but I imagine that should leave trace in the logs!?

If I test the alarm it works fine and the siren acts as part of the system, as expected. Siren batteries changed last quarter so not sure what to think - the neighbours however are convinced the alarm was on several times and even for longer durations that the 3min, which is configured as alarm length...

JJ

 

[bernardgreen]

These "false alarms" are the only way the system can indicate that the siren's receiver is being blocked and therefore cannot respond to messages from the panel.

This is the same as the wires being cut on a wired system.

The siren cannot send an "I am blocked" message to the panel so the log will be unaware of the blocking. If the signal causing the block is strong enough to also affect the receiver in the panel then the log should have a record of this.

In the past Yale recommended turning of the jamming detection if there were too many "false alarms". That is not a good idea.

Some wireless alarms have been targeted by criminals with transmitters that block the siren to cause a false alarm. When the owner eventually turns of the jamming detection to prevent any more "false alarms" the criminals then know that they can then block the siren and break in without the siren sounding.

 

[JohnD]

Jamming by radio signal is exceptionally rare. However the siren can go off if the casing's anti-tamper switch is operated, for example if the fixing screws are not tight and it moves in strong wind.

There is no particular reason why the alarm should go off more when you are on holiday than when you are at home, unless perhaps you have only recently fitted it, or do not usually turn it on. The tamper activation would happen even if it was not set.

If you truly have an interfering radio signal causing the interference alarm, you are pretty well unique. It is especially curious that there is no record on the panel, unless it is not close to the siren. So don't start from the assumption that Bernard's is a probable cause.

How long have you had the alarm? Are you in an ordinary domestic house in an ordinary residential street? Is there a taxi radio transmitter or a welding workshop? How long has the alarm been installed? How old are the batteries?

Presumably the neighbours looked at least once, and saw that the led's on your siren were flashing, so they know it was your alarm and not, for example, a car alarm nearby.

Set the panel to chime when the front and back doors are opened. You will hear the bleep. In the event that there is a lot of interference blocking the signal, it would prevent the panel bleeping if interference coincides with you opening the door. I would start next by verifying that the siren is securely fixed and the batteries are good. The anti-tamper button on the siren casing presses against the wall when the lid is fixed, you can see it. If the surface of the wall is uneven you may need to screw a bit of wood or filler or something onto the wall so that the tamper button has a firm seating.

Did these nuisance alarms start to happen after the batteries had just been changed, disturbing the siren casing? Have they occurred when you were at home?

 

[jjdiy7]

thanks for the comprehensive response - would you know for how long the siren can be sounding in such scenarios? for example is there an automatic cut-out or would it sound until the jamming stops?

 

[jjdiy7]

unless perhaps you have only recently fitted it, or do not usually turn it on.

it was fitted in 2010 and is away armed during the day (there is no one home during the day) / perimeter only night time(home arm). the only time the alarm goes off is when my wife takes too long to disarm it (presently delay set at 20secs.

Are you in an ordinary domestic house in an ordinary residential street? Is there a taxi radio transmitter or a welding workshop?

quiet neighbourhood, outskirts of town and standard house (3bed semi) - the only thing I can think of is power-lines 4 rows of houses from us, but they have been there all along.

Set the panel to chime when the front and back doors are opened. You will hear the bleep.

this has always been enabled for the front door and you can hear the panel chime. the control panel is also literally within a meter or two from the siren on same level inside, but there is a TV near the panel and our BT Infinity router is across the room at about 5-6m from panel. I only mention this as I was browsing the forum and I noticed warnings about proximity of those. we've also never had the siren sounding when disarmed or night time while only the perimeter is armed(home arm), which is why I was initially puzzled.

I would start next by verifying that the siren is securely fixed and the batteries are good. The anti-tamper button on the siren casing presses against the wall when the lid is fixed, you can see it. If the surface of the wall is uneven you may need to screw a bit of wood or filler or something onto the wall so that the tamper button has a firm seating.

I'll check how tight it is, but I think it is. it's a brick wall and when I swapped the batteries 2-3 months ago I did try to move the siren and the tamper did not activate, but I take your point.

Did these nuisance alarms start to happen after the batteries had just been changed, disturbing the siren casing? Have they occurred when you were at home?

no, allegedly happened when we were away on three consecutive days 1,2&3/09 - they even complained to the council, but I've never had a case before when the siren will be sounding and the alarm would not call me etc..

 

[JohnD]

I have been browsing the HSA6400 instructions.

I notice it says that "Siren produces a series of pips when armed or disarmed" then it may be low batteries in the siren, but it can also indicate that the Siren Tamper switch has activated.

"The siren tamper switch has been disturbed. Check that the siren produces a series of pips only when arming, indicating a tamper fault. Check that the siren cover is firmly secured and the tamper switch plunger is in contact with the wall. If not use suitable packing material to fill gap."

Did you get any pips on arming?

The control unit will flash the yellow light if it detects a problem, which includes interference, which you say it is not doing.

The HSA6400 instructions mention that the siren has jamming detection, but as they expect interference to be detected by the control unit, they do not say more. Looking at instructions for an older model, it mentions that the siren's anti-jamming can be turned off by setting the siren's internal dipswitch no. 7 to "on." However I do not recommend this, as IMO the problem is most likely not caused by jamming.

If you turn off jamming detection on the siren (perhaps it is close to some radio equipment, and moving it would be a better solution), the control unit continues to function, and its dial-out and internal sensors and sounder continue to work. In your case I think it is significant that the control panel inside the house has not detected interference. If you or your neighbour has, for example, a wireless baby monitor close to your siren, it might cause interference, and moving the siren to the other side of the house could cure it. However I will say that I have used Yale alarms in houses with wireless doorbells, baby monitors and car remotes without interference problems. The only cases of interference or signal blocking of Yales I have heard of are from radio transmitters and welding equipment, which are not usual in an ordinary domestic house in an ordinary residential street.

On an independent siren, you can set the siren sound length. I don't know if that still works if you have a siren controlled by a control unit.

For an independent siren, the settings are:
J3 on, J4 on = 3 minute siren ‘on’ period
J3 off, J4 on = 5 minute siren ‘on’ period
J3 on, J4 off = 10 minute siren ‘on’ period
J3 off, J4 off = 1 second siren ‘on’ test period

I am sure it would be best to leave the siren settings as in the HSA6400 instructions, except perhaps when you are tinkering. On occasions when I have tinkered, I used to bring the siren into the house, and put it in a cupboard, surrounded by cushions, to avoid noise nuisance. The 1-second period is also useful to avoid annoying the neighbours.

You can also bring the siren into the house for a trial period (fix it up high on the landing so an intruder can't easily get at it, but will be startled and disorientated by the loud noise) which will help identify if the noise was coming from e.g. a nearby car alarm or a different house. You could put your spare dummy box up in its place temporarily.

 

[E999]

OK ive fitted a few of these...the siren sounding and not displaying a fault on the log is a classic case of the tamper on rear of siren......

Take off wall and stretch spring on rear of siren.....OR pack the spring out...

Its quite common on this siren when its several years old!

 

[jjdiy7]

thank you all for the useful tips.