RCD tripping in new build help

[flameport]

If someone was to pull the main fuse outside his property that they could just break in without alarming the neighbours because alarms should never go off when the power is removed?

Alarm panels have a rechargeable battery inside, which will power the alarm in the event of power failure. The capacity of this battery is selected by the installer so it is capable of powering the panel and all devices connected to it for a certain time, which would be at least 24 hours.
The external siren also has it's own battery inside.

If the alarm is not set, a power failure will have no effect, other than a warning being shown on the panel.
If the alarm is set, power failure won't do anything either, but if someone then breaks in, the alarm will sound in the usual way, as it is being powered from the battery.
If someone cuts the cables to the external siren, it will sound using it's own internal battery, as it requires continuous power from the panel both to charge it's own battery and indicate that the panel is still connected.

If the internal panel battery is ruined, not charged or not installed, power failure will cause the external siren to operate, as there is no signal from the panel.

The internal battery and external siren module need to be replaced at certain intervals, which is why all those people with alarms that blare off every time there is a minor power issue clearly haven't had it serviced or maintained since it was installed.

 

[EFLImpudence]

I presumed with any alarm if any cable was cut the alarm would sound.

I'm not in the alarm business but that was my thinking, too.

Had a job this week where I asked the customer to switch off/disconnect anything that may be affected when I turned off the power.
He forgot about the alarm and when the power went off the alarm sounded.
I have had similar in the past.

Ours (Veritas fitted by ADT) doesn't go off when the power is cut, it runs off the battery until the power is restored. If the alarm goes off then the siren box is losing contact with the control box and acting as if a wire has been cut - perhaps the alarm battery needs changing or it isn't wired correctly.

Doesn't that contradict?

 

[EFLImpudence]

Just seen flameport's post

so need to tell customer to have the alarm serviced.

 

[Lectrician]

It is EXACTLY as flameport has stated. Any intruder alarm who's siren goes off during a power failure is faulty or incorrectly fitted.

 

[sparkwright]

The alarm keeps going off when the RCD trips so I was thinking of putting the alarm on the mains side so he won't have the same problem again in 10 / 15 years...

What do you mean, the mains side?

What happens in 10/15 years?




When doing your IR tests, has every bit of cable been tested, for example, cables that can be turned off by switches?

You need to identify which circuit the fault is on first.

You don't make it clear if this a dual RCD board, a high integrity board, a split load board - some protected some unprotected, or a board where the main switch is the RCD.

If you can describe this better, it may be possible to rearrange the board temporarily to highlight which circuit the fault is - though not the best idea if tripping can occur very infrequently.

 

[Chri5]

By the main side I'd assume the op means direct, not on rcd rails.

Although a rcbo would be likely if feed doesn't comply with non rcd regs route and installation wise.

 

[Chrisbly]

You have all been very helpful. This is my first post and I am very overwhelmed by all the feedback I have recieved so thank you very much.

Just to clarify a few points:

One of the first questions I asked was has any work been done and the answer was no and after looking around this was a no also so it seems no screws or nails have gone through any cable.

My understanding of alarms is a lot better than it was as I was clearly missing the most simplist of things. The alarm wasn't my main concern nor my job but is helpful knowing so I can advise customer.

The ir tests were between switches on and off too. I said the main side before - It is a dual RCD board with a mains switch with a spare and would be able to make room for one on a main and obviously wouldn't look to doing this as a permanent solution.

Once again, thanks for all your feedback.. I will update on the problem after my next visit

Chris

 

[sparkwright]

The usual suspects are water in outdoor fitting, pinched wire on metal accessory, drilled cable.

Doesn't help matters when the tripping is so random, and IR tests don't appear to help you.

This is why it's desirable, and expensive, to have RCBOs.

 

[Lectrician]

Ours (Veritas fitted by ADT) doesn't go off when the power is cut, it runs off the battery until the power is restored. If the alarm goes off then the siren box is losing contact with the control box and acting as if a wire has been cut - perhaps the alarm battery needs changing or it isn't wired correctly.

Doesn't that contradict?

No.

The external siren has two methods of protection. The panel monitors the siren by looking for a 'tamper return', this is a 0v signal taken from the 0v in the siren, through some tamper switches (lid, wall, screws) in the siren and back to the panel. If the cable is cut, 0v is lost, if cover removed, 0v is lost. In both cases, panel will alarm.

The siren will also 'hold off' as long as it has a constant 12v supply to it (which charges it's little battery and operates the flip-flop LED's). If this 12v supply is lost (cable cut, panel looses BOTH battery and mains), then the siren will sound from it's internal battery.

All other cabling for the alarm is also tamper protected by either a closed loop through tamper switches in the detectors, or via EOL resistors. The panel will know if these cables are cut and will sound either an internal or external alarm, depending on if the system was set or not.

The mains supply is NOT monitored, other than to provide a warning should it fail (a beep or flashing LED or banner message on the keypad). It should never go into alarm at the loss of power. Imagine an estate during a power failure - 30+ alarms going off? really? You always hear the odd one, and these are the faulty ones.

This is one reason the police encourage alarms to be maintained - an alarm that goes off regularly, and for no reason, is quickly ignored by all around.

 

[IJWS15]

Ours (Veritas fitted by ADT) doesn't go off when the power is cut, it runs off the battery until the power is restored. If the alarm goes off then the siren box is losing contact with the control box and acting as if a wire has been cut - perhaps the alarm battery needs changing or it isn't wired correctly.

Doesn't that contradict?

Probably, meant to refer to the wire between the control box and the siren.

 

[Chri5]

Cumalitive mA leaks? Some items are earth leaky, old PSUs for pcs, some ovens, some boilers, some washer machines.

Does the trip tie in with say the programmer kicking in the boiler, dual to dawn lighting comming on, when a kid powers up the hand me down PC. Ditto iron or kettle?

If you do suspect a certain circuit you might have space to shift it over to an rcbo on the direct