Alarm triggered by switching a light on.

[shirley83]

Hi Guys.

Last week I moved into my new property, she is not perfect and needs some TLC. I have a very positive attitude and I want to learn and try to better myself where possible. This is the main reason for joining this forum.

The first issue I have come across is the house alarm and I would like to sort it sooner rather than later for security. When I go into garage via the internal door and switch on the light the alarm is triggered when it is other wise disabled. The external siren does not sound, just the internal bell box and key pads make a noise and the displays flashes the red tamper LED. I just enter the code and the alarm disables, press the reset and all is fine until the next time I turn on the light. This is not always the case but the same happens when I turn on the utility light with is next door to the garage, I'm guessing they are on the same lighting ring main. There is no PIR in the garage.

My first assumption was the alarm takes its 240v from the lighting ring main and switching the light on causes some fluctuation and the alarm goes off.

I have tried the following to locate the issue so far:

I have verified the external sounder does actually works via the test mode. It does.
Removed the front cover of the main alarm box. Checked all the glass fuses. They are fine.
Replaced the lead acid battery as that was dated 2002.

The issue is still happening.

At the weekend I plan to locate where the alarm takes its 240v from. As a test wire a plug onto it and plug it into a socket to see if that verifies thoughts of interference and see if the issues go away.

Check all the wiring in the lights to see if anything looks a miss.

Any help would be welcome here as after that, I'm out of ideas.

The alarm is a Veritas R8 from around 2002 with 2 key pads, one in the main entrance and one handily next to the garage door.

Thanks in advance.

Ash

 

[EFLImpudence]

Hello Shirley or Ash?

We do have an Alarms forum which will be more specialist. I'll ask for your post to be moved.

Someone here may know in the meantime.

 

[shirley83]

OK thanks. Sorry newbie error.

 

[EFLImpudence]

No matter. See you another time.

 

[sparkymarka]

2 things to check .... If you have a multimeter check on AC between the earth in the panel and 0v if more than 5 v AC fit a act 1313 filter if the problem still happens fit a mains filter

 

[securespark]

My guess is that the two lights triggering this response are fluorescent strips?

Check that the panel's circuit is not the same circuit that the lighting is on. Fluorescent fittings sometimes cause a slight surge on switch-on and this may be causing the panel to lock out.

Switching inductive loads, eg, pumps, fridges and fluorescents - can induce interference into the mains electricity supply, as can the panel's wiring being run close to any mains cabling.

Induced AC noise can cause the DC supply to become unstable, leading to unexplained false alarms. Testing between DC voltage and earth with your multimeter switched to the 20VAC range will show much induced AC there is in the alarm cables connected to the control panel. Now connect the probes across any DC+ve output and mains earth. The reading should not exceed 1.2V AC.

Panel crashes like this can also be caused by an unstable AC/ DC supply or an insufficient capacity of back-up battery in the panel.
You should test to see if you have a stable DC voltage of somewhere between 13.5V minimum and 14.0V maximum at the battery terminals.

If the problem is induced AC, then you could try fitting an ACT 2323 main spike suppressor (around £12 + the dreaded) and an ACT 1313 12V spike suppressor (around £6 + the dreaded) to the panel.
The 2323 is wired across the mains supply of the panel and any PSU's on the system (don't forget the earth connection) and the 1313 is wired across the DC supply with the green wire to the mains earth terminal.

Once the 1313 is fitted, you should retest to ensure the reading falls below 1V AC.

You will need to check your panel actually has an earth connection to it. A rudimentary check, if you cannot do an Earth Fault Loop Impedance test is to check with a multimeter that you have continuity between a socket earth terminal (via a 13A plug) and the earth terminal on the panel.

 

[securespark]

2 things to check .... If you have a multimeter check on AC between the earth in the panel and 0v if more than 5 v AC fit a act 1313 filter if the problem still happens fit a mains filter

Honestly! I go away mid-post to put a child in bed and when I hit "Post Reply" I find someone has beaten me to it...

 

[winston1]

Hi Guys.


My first assumption was the alarm takes its 240v from the lighting ring main
Ash

There is no such thing. Lights are wired on radial circuits.

 

[securespark]

 

[Mikefromlondon]

Why do I think the previous owner may have deliberately wired the alarm to come on when someone switches on the garage light or utility room light, that is a possibility, and since it does not cause a main alarm but a tamper fault, one way to see if this is the case, find out which zone or loop is responsible then bridge its tamper circuit to see if it still trips, if it does then it is related to some sort of electrical interference, if it no longer trips, then it is likely the previous owner wired it in such a way possibly using a mains relay connected to light circuit, I know of someone who asked me if his alarm panel can be wired to such that even when it is disabled, it monitors his garage at the back of his house which he uses for storage, and wants it alarmed all the to alert him with a buzzer sound instead of a main alarm.

 

[shirley83]

Thanks for the detailed response. This will give me plenty to go at over the weekend.

My guess is that the two lights triggering this response are fluorescent strips?

Check that the panel's circuit is not the same circuit that the lighting is on. Fluorescent fittings sometimes cause a slight surge on switch-on and this may be causing the panel to lock out.

Switching inductive loads, eg, pumps, fridges and fluorescents - can induce interference into the mains electricity supply, as can the panel's wiring being run close to any mains cabling.

Induced AC noise can cause the DC supply to become unstable, leading to unexplained false alarms. Testing between DC voltage and earth with your multimeter switched to the 20VAC range will show much induced AC there is in the alarm cables connected to the control panel. Now connect the probes across any DC+ve output and mains earth. The reading should not exceed 1.2V AC.

Panel crashes like this can also be caused by an unstable AC/ DC supply or an insufficient capacity of back-up battery in the panel.
You should test to see if you have a stable DC voltage of somewhere between 13.5V minimum and 14.0V maximum at the battery terminals.

If the problem is induced AC, then you could try fitting an ACT 2323 main spike suppressor (around £12 + the dreaded) and an ACT 1313 12V spike suppressor (around £6 + the dreaded) to the panel.
The 2323 is wired across the mains supply of the panel and any PSU's on the system (don't forget the earth connection) and the 1313 is wired across the DC supply with the green wire to the mains earth terminal.

Once the 1313 is fitted, you should retest to ensure the reading falls below 1V AC.

You will need to check your panel actually has an earth connection to it. A rudimentary check, if you cannot do an Earth Fault Loop Impedance test is to check with a multimeter that you have continuity between a socket earth terminal (via a 13A plug) and the earth terminal on the panel.

Sorry, my bad. I'm no electrical expert, just a keen DiY person. I've googled and I now understand the difference.

There is no such thing. Lights are wired on radial circuits.

I agree, I have not totally discounted this as the source, it could be intentional. I think if there turns out to be little or no interference on the line, it is more than likely intentional. The house alarm was installed when the property was build by persimmon (before this house I lived at the other end of the estate so i'm familiar with the houses and how stuff was installed) and their contractors installed the alarm. The owner will have had to have had this configuration done after the main installation, but possible.

Why do I think the previous owner may have deliberately wired the alarm to come on when someone switches on the garage light or utility room light, that is a possibility, and since it does not cause a main alarm but a tamper fault, one way to see if this is the case, find out which zone or loop is responsible then bridge its tamper circuit to see if it still trips, if it does then it is related to some sort of electrical interference, if it no longer trips, then it is likely the previous owner wired it in such a way possibly using a mains relay connected to light circuit, I know of someone who asked me if his alarm panel can be wired to such that even when it is disabled, it monitors his garage at the back of his house which he uses for storage, and wants it alarmed all the to alert him with a buzzer sound instead of a main alarm.

Once again, thanks for all the help.

 

[securespark]

Mike: it sounds like the alarm is not going into alarm condition when set but locking out in day mode.

 

[bernardgreen]

There is no such thing. Lights are wired on radial circuits.

Lights are almost always wired as radial circuits but they can and occasionally are wired as a ring final.

 

[Handymanjo]

Could be poor installation ?
Low volts alarm cables ran with mains cables at install ?
You need to check for a/c volts by using multimeter between earth and ov volts d/c
Fitting act 1313 filter could stop problem and also check battery while inside control panel.
Caution 240v inside panel.

 

[shirley83]

Guys,

Sorry for the delay, having a new baby in the house things move slowly. This problem has now come to a head so it needs fixing and I looked at it over the weekend.

I have tested the tamper circuit with my multi meter and that has continuity so I don't thing it is a tamper issue also giving the alarm goes off when something is triggered on the lighting circuit.

So it was time to check the 240v feed from the lighting circuit. As result I've wired a temp circuit to power the alarm now off of socket ring main and so far (72 hours) the alarm has not gone off once. I did note that when I disconnected the original connection the earth connection in the fuse spur was loose. Firstly I will wire it back up as normal and see if the problem comes back, pretty sure it will. So then i think my options are, 1 trace the feed of original wire back to the lighting ring and see where it runs and looks for interference. I'm hoping that will be easy as it should run in the garage loft. 2. Disconnection the original feed and wire a new one in from the socket ring main into the fuse spur. 3. If the above fails try a filter.

Thanks for the assistance with this.