Info on Viper circuit false alarm.

[vykingman 0]

Can anyone help with a bit of fault diagnosis on a viper (x2) circuit

This is an older Scantronic system where I am getting false alarms on a circuit with two vipers - about eight(8) years old.

Strangely neither viper LED flashes after false alarm. When walk tested both vipers flash as they should.

I have checked the internal viper wiring and all good.

Question is this a viper problem or wiring.

Any help would be good - thank you.

[PeterJames 462]

Could be many things, so a bit more info is required. If its not wired eol then it may be a cable fault, it may also still be a cable fault if the power is dropping. When was it last serviced? How old is the standby battery?

[vykingman 0]

Many thanks for your prompt reply.

This is has been a fully serviced system since it was fitted. The standby battery was replaced last October on its annual service.

[MrHappy 1,267]

are you the system owner or the alarm eng?

[vykingman 0]

I am the system owner.

The company I was with has been taken over by another. Not happy with new company so have cancelled service contract.

[PeterJames 462]

On the walk test do the lights latch on? Do you have a button you have to press to reset them or are they reset when you set the alarm?

Blitz is a good company in Kent if your thinking of changing

[vykingman 0]

On the walk test when the viper is knocked the lights do come on. They are reset when the alarm is reset.

Thanks for the info on Blitz.

[PeterJames 462]

okay this narrows it down a little, do you have other powered detection, motion detectors or beams ect?  

[vykingman 0]

The two vipers form part of a perimeter protection for use at night.

the room also has pir detection as backup when house is vacant.

 

[PeterJames 462]

So the pir has not been armed so you dont know if it is false activating as well? Or have the vipers activated whilst the property was vacant and the pir was armed

[vykingman 0]

The pir is a separate circuit. The false alarm happens when it's on part set perimeter only. It's always the same viper zone that shows is activated.

[MrHappy 1,267]

2 hours ago, vykingman said:

I am the system owner.

 

okay,

 

FSL or DP ?

[vykingman 0]

Sorry  - FSL or DP

 it sure what they are

[MrHappy 1,267]

Fully Supervised Loop an end of Line resistor circuit

 

or

 

Double Poled = An alarm loop & a tamper loop

[vykingman 0]

This is a guess  but bare with me. If the viper has wires in both 24hr and alarm terminals would that make it double poled?

infact all terminals have been used.

 

[al-yeti 392]

50 minutes ago, vykingman said:

The pir is a separate circuit. The false alarm happens when it's on part set perimeter only. It's always the same viper zone that shows is activated.

So full set no problem?

1 minute ago, al-yeti said:

So full set no problem?

And vipers are not active on full set?

[MrHappy 1,267]

Normally a competent alarm engineer would  measure the circuits,

 

low Ohms between each pair of cables, high Ohms between cables which ain't paired.

 

With the system running on battery power only, measure the voltage at each device to ensure it high enough.

 

Full set the system & check the device operates as intended,

 

If all fine I would swap the circuits with another zone & place the viper circuit on soak test.

 

You can do all this yourself or just find a competent alarm co. to look after your system.....

 

[PeterJames 462]

There are several things that could be causing your problem as follows:

 

1. Auxiliary power failing. Loose fuse or poor connection at the panel down powering the vipers will cause the circuit to go open giving the impression that they had activated. This is why its important to know If the pir were to activate along with the vipers when the system is fully set as this would indicate that it is a power problem.

 

2. The cables to the vipers may have a fault on them, the fact that you have nt had a tamper fault would suggest that the 24hr loop is okay, if you swap the pair both ends and you start to get tamper faults then you know its the cable. Although it could also be an  intermittent short between the tamper and alarm circuit. So if the false alarms continue it still maybe a short between alarm and tamper, To prove this I would remove the wires from the tamper circuit and fit a link, if the fa's stop its a short problem.

 

3. The panel itself. It could be just the zone or it could be dropping power

 

4. The vipers. As there is two of them it is very unlikely, but not impossible.

 

My money is on 1 or 2 the detectors seem to work as they should when tested and the panel operates correctly, but an intermittant fault can be difficult to find  especially without a multimeter. 

 

 

 

[datadiffusion 489]

No-one seems to have asked what panel it is. So I am now

[vykingman 0]

Its a Scantronic 9800 Plus. Mains/battery

 

[vykingman 0]

The vipers are

3 hours ago, al-yeti said:

So full set no problem?

And vipers are not active on full set?

The system does FA on full set - its the same viper zone that is activated - but no viper LED flashing?

[vykingman 0]

1 hour ago, PeterJames said:

There are several things that could be causing your problem as follows:

 

1. Auxiliary power failing. Loose fuse or poor connection at the panel down powering the vipers will cause the circuit to go open giving the impression that they had activated. This is why its important to know If the pir were to activate along with the vipers when the system is fully set as this would indicate that it is a power problem.

 

2. The cables to the vipers may have a fault on them, the fact that you have nt had a tamper fault would suggest that the 24hr loop is okay, if you swap the pair both ends and you start to get tamper faults then you know its the cable. Although it could also be an  intermittent short between the tamper and alarm circuit. So if the false alarms continue it still maybe a short between alarm and tamper, To prove this I would remove the wires from the tamper circuit and fit a link, if the fa's stop its a short problem.

 

3. The panel itself. It could be just the zone or it could be dropping power

 

4. The vipers. As there is two of them it is very unlikely, but not impossible.

 

My money is on 1 or 2 the detectors seem to work as they should when tested and the panel operates correctly, but an intermittant fault can be difficult to find  especially without a multimeter. 

 

 

 

Many thanks for your input on this. I will work through your suggestions and see what I come up with. Not to sure how to test your first suggestion as the viper zone is the only one that is indicated on the control panel.

[PeterJames 462]

1 minute ago, vykingman said:

The vipers are

The system does FA on full set - its the same viper zone that is activated - but no viper LED flashing?

That narrows it down a bit use the 24hr tamper wires as the circuit and link out the tamper circuit at the panel. If it stops you either have an intermittent short between tamper and alarm or an intermittent open circuit .

[vykingman 0]

2 hours ago, MrHappy said:

Normally a competent alarm engineer would  measure the circuits,

 

low Ohms between each pair of cables, high Ohms between cables which ain't paired.

 

With the system running on battery power only, measure the voltage at each device to ensure it high enough.

 

Full set the system & check the device operates as intended,

 

If all fine I would swap the circuits with another zone & place the viper circuit on soak test.

 

You can do all this yourself or just find a competent alarm co. to look after your system.....

 

Thank you for your input on this problem. I can check your suggestions and see what I come up with.

[PeterJames 462]

2 minutes ago, vykingman said:

Many thanks for your input on this. I will work through your suggestions and see what I come up with. Not to sure how to test your first suggestion as the viper zone is the only one that is indicated on the control panel.

If the pir is not activating when full set logically it is unlikely to be power at the panel. It may still be an intermittent power fault on the viper cable