SPC 4300 sensor resistance problem

skellig_rocks

Hi,


My house alram (SPC 4300) starts giving false alarm and I looked at the log and one of my sensor has spiked resistance occasionally (from 0R to upto 900R). What is the usual cause of the problem or if the sensor needed to be replaced?


Thanks

altor

skellig_rocks wrote: »

Hi,


My house alram (SPC 4300) starts giving false alarm and I looked at the log and one of my sensor has spiked resistance occasionally (from 0R to upto 900R). What is the usual cause of the problem or if the sensor needed to be replaced?


Thanks

More than likely faulty but as you seem to have a few devices on the zone it could be either sensor.
Best way to test is by using a multimeter.

skellig_rocks

Thanks alter,

Funny thing is those resistance spikes only happen 2-3 times a month, each last around 15 minutes, then back to 0R and stay 0R.

Is it common for a shock sensor to behave like that when it is approaching EOL?

altor

skellig_rocks wrote: »

Thanks alter,

Funny thing is those resistance spikes only happen 2-3 times a month, each last around 15 minutes, then back to 0R and stay 0R.

Is it common for a shock sensor to behave like that when it is approaching EOL?

A can show faulty sensor will show higher resistance.
Opening and closing the sensor can change the reading be that give you a higher reading or lower.

skellig_rocks

Hi altor,

How do I manually check the resistance of a sensor?

Do I check the resistance between the connectors connected with the white wires, as shown on the picture?

Thanks

altor

skellig_rocks wrote: »

Hi altor,

How do I manually check the resistance of a sensor?

Do I check the resistance between the connectors connected with the white wires, as shown on the picture?

Thanks

Remove the resistor from the last device on the zone and connect the wires to the last device. 
Sometimes the resistor is in the control panel so just remove this and connect the cable ends from that zone to the multimeter.
Set the meter to 200 Ohms and take a note of the reading.
Each device you have on that zone you will need to tap 10-20 times plus open and close each contact one by one. If you do connect the meter in series with the last device then make sure you disconnect the zone in the control panel plus any resistors on the loop and join the cable together there.
After each one, check if the reading has changed. 
If it does not return to in or around the same value remove that device, join the cables from the alarm circuit together and move on to the next device.
After this you should have a circuit with a lower resistance value that remains the same after you tap or open any device.
Replace any faulty devices plus replace the EOL resistor and rewire the zone back into the panel.

Waesfjord

Hi,

Similar problem with an SPC 4230 unit. Have recently started to receive false alarms from upstairs windows circuit. This contains 5 contact + 2 shock/contact sensors.

One of the windows was stuck closed, rcenttly had someone out to repair the window mechanism, now working. This I suspect may have led to damage to shock contact on this window.

Date from system is as follows below. Suspect window is #1, other window with shock contact is #2.

All windows were closed till 18:16.
I opened Window #1 at 18:16:14, closed after a few seconds. Resistance stayed high.
I opened Window #2 at 18:18:38, closed after a few seconds, reopened at 18:19:54 and closed again after a few seconds.


Based on this info, I strongly suspect Window #1 sensor is not working, needs replacement. This make sense as aligns with data below, and culprit for work on window recently?

Can anyone advise where I can pick up a compatible (wired) white Aritech shock/contact to swap out head on existing sensor, online probably best as I'm based in Dunshaughlin, likely nothing local.

Time Input Resistance
13/06/2020 18:24:02 Open 700R
13/06/2020 18:22:11 Open 900R
13/06/2020 18:20:22 Open 1.1K
13/06/2020 18:20:17 Open 1.6K
13/06/2020 18:20:17 Open 1.2K
13/06/2020 18:20:13 Open 1.0K
13/06/2020 18:20:07 Open 1.4K
13/06/2020 18:19:54 Open INF
13/06/2020 18:18:49 Open 800R
13/06/2020 18:18:49 Open 4.9K
13/06/2020 18:18:38 Open INF
13/06/2020 18:18:25 Open 1.6K
13/06/2020 18:18:24 Open 1.4K
13/06/2020 18:18:24 Open 1.6K
13/06/2020 18:17:08 Open 1.1K
13/06/2020 18:17:03 Open 900R
13/06/2020 18:17:01 Open 1.2K
13/06/2020 18:17:00 Open 1.0K
13/06/2020 18:16:59 Open 1.2K
13/06/2020 18:16:57 Open 1.0K
13/06/2020 18:16:56 Open 1.2K
13/06/2020 18:16:56 Open 1.4K
13/06/2020 18:16:54 Open 1.0K
13/06/2020 18:16:50 Open 1.4K
13/06/2020 18:16:37 Open 1.7K
13/06/2020 18:16:19 Open INF
13/06/2020 18:16:17 Open 1.3K
13/06/2020 18:16:14 Open 1.6K
13/06/2020 18:16:09 Open 500R

skellig_rocks

I ended up repositioning the inertia sensor (the golden cylinder with plastic cover) as the one I had trouble with was not "vertically" positioned (there is a arrow on the sensor and it should be pointing downward, I think). No more problem since.

Waesfjord

good to hear you have it reolved. Mine worked fine for 3years, now problem, so most likely damaged, not likely a sensor mount issue.

altor

Waesfjord wrote: »

Hi,

Similar problem with an SPC 4230 unit. Have recently started to receive false alarms from upstairs windows circuit. This contains 5 contact + 2 shock/contact sensors.

One of the windows was stuck closed, rcenttly had someone out to repair the window mechanism, now working. This I suspect may have led to damage to shock contact on this window.

Date from system is as follows below. Suspect window is #1, other window with shock contact is #2.

All windows were closed till 18:16.
I opened Window #1 at 18:16:14, closed after a few seconds. Resistance stayed high.
I opened Window #2 at 18:18:38, closed after a few seconds, reopened at 18:19:54 and closed again after a few seconds.


Based on this info, I strongly suspect Window #1 sensor is not working, needs replacement. This make sense as aligns with data below, and culprit for work on window recently?

Can anyone advise where I can pick up a compatible (wired) white Aritech shock/contact to swap out head on existing sensor, online probably best as I'm based in Dunshaughlin, likely nothing local.

Time Input Resistance
13/06/2020 18:24:02 Open 700R
13/06/2020 18:22:11 Open 900R
13/06/2020 18:20:22 Open 1.1K
13/06/2020 18:20:17 Open 1.6K
13/06/2020 18:20:17 Open 1.2K
13/06/2020 18:20:13 Open 1.0K
13/06/2020 18:20:07 Open 1.4K
13/06/2020 18:19:54 Open INF
13/06/2020 18:18:49 Open 800R
13/06/2020 18:18:49 Open 4.9K
13/06/2020 18:18:38 Open INF
13/06/2020 18:18:25 Open 1.6K
13/06/2020 18:18:24 Open 1.4K
13/06/2020 18:18:24 Open 1.6K
13/06/2020 18:17:08 Open 1.1K
13/06/2020 18:17:03 Open 900R
13/06/2020 18:17:01 Open 1.2K
13/06/2020 18:17:00 Open 1.0K
13/06/2020 18:16:59 Open 1.2K
13/06/2020 18:16:57 Open 1.0K
13/06/2020 18:16:56 Open 1.2K
13/06/2020 18:16:56 Open 1.4K
13/06/2020 18:16:54 Open 1.0K
13/06/2020 18:16:50 Open 1.4K
13/06/2020 18:16:37 Open 1.7K
13/06/2020 18:16:19 Open INF
13/06/2020 18:16:17 Open 1.3K
13/06/2020 18:16:14 Open 1.6K
13/06/2020 18:16:09 Open 500R

Could be any device on the loop. Best to have it checked with a multimeter.

Here is a link to the suppliers, they would have replacement parts.

altor

skellig_rocks wrote: »

I ended up repositioning the inertia sensor (the golden cylinder with plastic cover) as the one I had trouble with was not "vertically" positioned (there is a arrow on the sensor and it should be pointing downward, I think). No more problem since.

Pointing the arrow down would open the zone.
Are you sure this sensor is connected correctly to the alarm system?

skellig_rocks

altor wrote: »

Pointing the arrow down would open the zone.
Are you sure this sensor is connected correctly to the alarm system?

Sorry I double checked and the arrow should be pointing up NOT down.


Related to my original question, I opened the control panel enclosure and I could not find anything look like resistors inside. Would be grateful if you could point of where the EOL resistors may be located?




spc4300-whole.jpg
The control board


spc4300-connector.jpg
I wonder if this is the resistor?


spc4300-diagram.jpg
I guess I should be following the INPUT 8 circuit layout?


Thanks in advance!

altor

skellig_rocks wrote: »

Sorry I double checked and the arrow should be pointing up NOT down.


Related to my original question, I opened the control panel enclosure and I could not find anything look like resistors inside. Would be grateful if you could point of where the EOL resistors may be located?




spc4300-whole.jpg
The control board


spc4300-connector.jpg
I wonder if this is the resistor?


spc4300-diagram.jpg
I guess I should be following the INPUT 8 circuit layout?


Thanks in advance!

Resistor should be in last device on the loop.
Yes, it looks like it is wired in single end of line and tampers are loops through the Aux tampers.

skellig_rocks

altor wrote: »

Resistor should be in last device on the loop.
Yes, it looks like it is wired in single end of line and tampers are loops through the Aux tampers.

Thanks for the reply.

Do you have an example of how a resistor would looks like? As I could not locate any resistors for the zone with issues.

Does "a loop" mean all sensors/PIRs connected in a "single" zone, or for the system (i.e. all sensors/PIRs/sirens in whole house). The zone I am diagnosing with consists of 2 sensors in different rooms but I could not see any resistors in those locations and I could not find any resistor-like object in the control panel.

spc4300-sensor.jpg
I guess the small rectangle thing on the left of the main sensor is not a resistor? I think it is just an extension sensor to reach the other side of the window?


Thanks again for your help!

altor

skellig_rocks wrote: »

Thanks for the reply.

Do you have an example of how a resistor would looks like? As I could not locate any resistors for the zone with issues.

Does "a loop" mean all sensors/PIRs connected in a "single" zone, or for the system (i.e. all sensors/PIRs/sirens in whole house). The zone I am diagnosing with consists of 2 sensors in different rooms but I could not see any resistors in those locations and I could not find any resistor-like object in the control panel.

spc4300-sensor.jpg
I guess the small rectangle thing on the left of the main sensor is not a resistor? I think it is just an extension sensor to reach the other side of the window?


Thanks again for your help!

Best thing to do is meter out the cable from the panel end (zone with issue) and see if any resistors are used on the loop.
Yes all sensors on one zone id describe as a loop.

Yes it is a contact to cover the second opening on the window.

Waesfjord

altor wrote: »

Best thing to do is meter out the cable from the panel end (zone with issue) and see if any resistors are used on the loop.
Yes all sensors on one zone id describe as a loop.

Yes it is a contact to cover the second opening on the window.

So on my SPC4300 system, there are no end of line resistors on the two zones I checked (see pick 0980 attched for end of line contact). I meter'd out cable at panel, this confirms O/L whenever a contact broken on zone, to confirm.

• Is it not an additional security feature to have these end of line resistors, so system can differentiate between a short / tampler (O#/L) and open circuit (whatever end of line resistor is)? Any reason why resistors not used for my house, system was installed ~3years ago?

On doing resistance checks, loop was reading 22kOhms when I started (all windows closed).
I started going through windows one by one, then on open/close of a reed contacts, the closed loop resistance returned to 260Ohms rather than 22lOhms, so 1/100th original. A repeat open/close on same window had same readings.

Unclear if root cause this contact or another faulty one on loop that played up at same time affecting reading. Or does this really indicate this reed switch is faulty?

Throughout rest of checks, for reed contacts, they went o/l, then returned to 230Ohms when closed.
The 1st intertia sensor behaved same on open/close, loop resistance spiking when sensor tapped, peaking to ~1kOhm, then returning to 230Ohms.
The 2nd inertia sensor behaved same on open/close, loop resistance spiking to 1.6kOhms when tapped, then return to 270Ohms when left alone.

• Am I as well disconnecting the sensors and measuring resistance acorss each one in isolation, as not sure if anything conclusive above?

If so, on reed contacts, it's simple as replacing MM for the current red & black connections (see pick 0980).

• Can someone advise what I should expect a 'closed' reed contact resitance to be?

For the Aritech shock/contact, it's wired as per pic 0982, so can replace black connections or red connections respectively with multimeter to take measurements for contact & interia resistance.

• Any idea what should be the resistance on closed reed switch and a healthy interia sensor?

altor

Waesfjord wrote: »

So on my SPC4300 system, there are no end of line resistors on the two zones I checked (see pick 0980 attched for end of line contact). I meter'd out cable at panel, this confirms O/L whenever a contact broken on zone, to confirm.

• Is it not an additional security feature to have these end of line resistors, so system can differentiate between a short / tampler (O#/L) and open circuit (whatever end of line resistor is)? Any reason why resistors not used for my house, system was installed ~3years ago?

On doing resistance checks, loop was reading 22kOhms when I started (all windows closed).
I started going through windows one by one, then on open/close of a reed contacts, the closed loop resistance returned to 260Ohms rather than 22lOhms, so 1/100th original. A repeat open/close on same window had same readings.

Unclear if root cause this contact or another faulty one on loop that played up at same time affecting reading. Or does this really indicate this reed switch is faulty?

Throughout rest of checks, for reed contacts, they went o/l, then returned to 230Ohms when closed.
The 1st intertia sensor behaved same on open/close, loop resistance spiking when sensor tapped, peaking to ~1kOhm, then returning to 230Ohms.
The 2nd inertia sensor behaved same on open/close, loop resistance spiking to 1.6kOhms when tapped, then return to 270Ohms when left alone.

• Am I as well disconnecting the sensors and measuring resistance acorss each one in isolation, as not sure if anything conclusive above?

If so, on reed contacts, it's simple as replacing MM for the current red & black connections (see pick 0980).

• Can someone advise what I should expect a 'closed' reed contact resitance to be?

For the Aritech shock/contact, it's wired as per pic 0982, so can replace black connections or red connections respectively with multimeter to take measurements for contact & interia resistance.

• Any idea what should be the resistance on closed reed switch and a healthy interia sensor?

New sensors are about 0.5 Ohms.
Length of cable plus sensors in loop will also add to over all Ohms.
If you take it that there is no resistors on the loop and start at the panel with it disconnected and connected to the leads on the meter you will end up with X Ohms.
Set the meter to 200 Ohms and take a note of the reading.
Each device you have on that zone you will need to tap 10-20 times plus open and close each contact one by one.
After each one, check if the reading has changed.
If it does not return to in or around the same value remove that device, join the cables from the alarm circuit together and move on to the next device.
After this you should have a circuit with a lower resistance value that remains the same after you tap or open any device.

Waesfjord

Tks. Reed sensor is at fault, so have it bypassed, all ok now. Seems to be an unbranded velux style (??) contact. I'll pop up to Navan to one of the shops listed to get a spare.

On the EOL resistors - is one recommended or not really any benefit if the wiring is hidden in walls?

altor

Waesfjord wrote: »

Tks. Reed sensor is at fault, so have it bypassed, all ok now. Seems to be an unbranded velux style (??) contact. I'll pop up to Navan to one of the shops listed to get a spare.

On the EOL resistors - is one recommended or not really any benefit if the wiring is hidden in walls?

A manhunt contact is what it looks like.
If you bring the old one with you then you will have no problem replacing.

The EOL resistor is used to monitor the cable. Looking at the set up you have the sensors are not even tampered. If you are testing the system regularly then it should not be an issue. Grade one systems under EN50131 dont even have to be. You could configure the sensors but you would need engineer access to change zone hardware to suit the setup you configure.

Waesfjord

altor wrote: »

A manhunt contact is what it looks like.
If you bring the old one with you then you will have no problem replacing.

The EOL resistor is used to monitor the cable. Looking at the set up you have the sensors are not even tampered. If you are testing the system regularly then it should not be an issue. Grade one systems under EN50131 dont even have to be. You could configure the sensors but you would need engineer access to change zone hardware to suit the setup you configure.

Thanks. I'll pop up to local supplier during week to get that contact replaced so.

I have full engineer access to system. If there is benefit and someone can call out how to rewire the reed and shock/contacts and configure on SPC, then I'm up for it!!

altor

Waesfjord wrote: »

Thanks. I'll pop up to local supplier during week to get that contact replaced so.

I have full engineer access to system. If there is benefit and someone can call out how to rewire the reed and shock/contacts and configure on SPC, then I'm up for it!!

Plenty of diagrams on this thread here that will help you along the way

If you set them up for dual end of line then tamper will also need to be wired in.
If you set them up as single with no tamper then single end of line.
With single you could just put one resistor in series with the last device.

Waesfjord

altor wrote: »

Plenty of diagrams on this thread here that will help you along the way

If you set them up for dual end of line then tamper will also need to be wired in.
If you set them up as single with no tamper then single end of line.
With single you could just put one resistor in series with the last device.

Hi Altor,

Lots of info within, trying to absorb. So trying to understand / lay out options on how to wire/configure

1) Easiest mod is one resistor at end of line contact in series, tamper cabling not used, reconfigure zones on SPC as single EOL with appropriate resitance value chosen, this gives

Using e.g. a 4K7 resistor, all closed = 4K7, an open circuit = ZONE ALARM.

• If low / zero resistance, then does SPC generate a ZONE FAULT as should always expect at least 4K7?

2) Tamper circuit queries

There are two circuit guides in thread you provided as follows:
https://www.boards.ie/vbulletin/attachment.php?attachmentid=229605&d=1353530827
https://www.boards.ie/vbulletin/showpost.php?p=85724945&postcount=257

• I don't see any tamper circuit on the reed contacts I have in pictured on previous reply (pic 0980), as nothing on removable cover to break a circuit. There is a tamper circuit in the shock contact pictured though (GS713 model I think).
• Where they exist, is it best practice to simply wire the sensor tamper circuits in series with switches, so if sensor cover removed, you get the standard zone ALARM, same as when either reed switch / shok switch opens?

For dual,

• The wiring of my shock/ contact (see pic 0982 on earlier reply) is such that shock is in series of red cabling, reed is in series with black lcabling. Per schematic shown in 1st link above, would this wiring scheme then be a problem when also using resistors at end of line in this zone? e.g. if same window opened and banged, both red and black wiring then broken/open, so would get open loop back to panel rather that 9K4 (assuming use of 4K7 resistors) if all the sensors were on the one (red) cabling?

altor

Waesfjord wrote: »

Hi Altor,

Lots of info within, trying to absorb. So trying to understand / lay out options on how to wire/configure

1) Easiest mod is one resistor at end of line contact in series, tamper cabling not used, reconfigure zones on SPC as single EOL with appropriate resitance value chosen, this gives

Using e.g. a 4K7 resistor, all closed = 4K7, an open circuit = ZONE ALARM.

• If low / zero resistance, then does SPC generate a ZONE FAULT as should always expect at least 4K7?

Yes that would be the easier option if you used single end of line on the alarm side.
With a tamper someone has to remove a cover or cut a cable for it to activate.
Alarm side is more important but its normal practice to cover it on a new installation even tho for EN50131 you dont have to tamper for a grade 1 system.

Waesfjord wrote: »

2) Tamper circuit queries

There are two circuit guides in thread you provided as follows:
https://www.boards.ie/vbulletin/attachment.php?attachmentid=229605&d=1353530827
https://www.boards.ie/vbulletin/showpost.php?p=85724945&postcount=257

• I don't see any tamper circuit on the reed contacts I have in pictured on previous reply (pic 0980), as nothing on removable cover to break a circuit. There is a tamper circuit in the shock contact pictured though (GS713 model I think).
• Where they exist, is it best practice to simply wire the sensor tamper circuits in series with switches, so if sensor cover removed, you get the standard zone ALARM, same as when either reed switch / shok switch opens?

Usually the 2 tamper wires are twisted together and put under one of the spare terminal screws in the contact. Only shows a tamper if the cable is cut.

No, if you are wiring the tamper side of the device keep it separate from the alarm. That can cause all sorts of problems if fault finding.

Waesfjord wrote: »

For dual,

• The wiring of my shock/ contact (see pic 0982 on earlier reply) is such that shock is in series of red cabling, reed is in series with black lcabling. Per schematic shown in 1st link above, would this wiring scheme then be a problem when also using resistors at end of line in this zone? e.g. if same window opened and banged, both red and black wiring then broken/open, so would get open loop back to panel rather that 9K4 (assuming use of 4K7 resistors) if all the sensors were on the one (red) cabling?

The wiring for the alarm zone uses 2 cores from panel to last device.
If Red or Black then either one can be broken to open the circuit.

Waesfjord

Thanks for clarifications, can see my options clearly now.

If I wanted to change out the wired contacts to ones with tamper on the windows (mixture of casement and sash), what would be recommended? Best to stay with Aritech or is there class leader to consider? Ideally similar length as the MAXHUNT to cover holes in window.

So on SPC4320, I see there are two tamper inputs on panel, with jumpers in panel currently as not wired to field. Are these always monitored by default
by panel, no configuration options (e.g. resistor in series) to detect difference between short circuit and a healthy circuit?
As only two, presume you simply loop the variious tamper loops from various zones together from e.g. doors/windors on one, with PIRs on other?
Any that should not be included on tamper circuit (e.g. entry/exit)?

For dual EOL, I don't understand how the 2nd resistor (i.e. one in parallel) closes loop if any contact other than EOL contact opens? Do you not need to have a resistor in parallel across each contact within that zone?

In SPC, it gives options for use of many different resistors for single and dual setups (E.g. single as 1k, 1k5, 2k2, 4k7, 10k, 12k, then for dual 1K/470, 1K/1K, 1K0, 2k2...all the way through options up to 10k). Why so many options, and is 4k7/4k7 just a standard people follow?

altor

Waesfjord wrote: »

Thanks for clarifications, can see my options clearly now.

If I wanted to change out the wired contacts to ones with tamper on the windows (mixture of casement and sash), what would be recommended? Best to stay with Aritech or is there class leader to consider? Ideally similar length as the MAXHUNT to cover holes in window.

There are different types of contacts that would have a tamper.
Most are global so will work with any wired system.
You would have to ask the suppliers what they have.

Waesfjord wrote: »

So on SPC4320, I see there are two tamper inputs on panel, with jumpers in panel currently as not wired to field. Are these always monitored by default
by panel, no configuration options (e.g. resistor in series) to detect difference between short circuit and a healthy circuit?
As only two, presume you simply loop the variious tamper loops from various zones together from e.g. doors/windors on one, with PIRs on other?
Any that should not be included on tamper circuit (e.g. entry/exit)?

They can be used as tamper circuits, they are linked out to close the tampers.
Its best to keep each loop separate as if you had them all grouped together and had an fault on a tamper on a device it would take time to find the fault.
If you are going to dual the sensors then you would just be putting 2 wires in the control panel end, same as what is already in place and setting up the hardware to suit.
You can tamper everything or nothing with most systems.

Waesfjord wrote: »

For dual EOL, I don't understand how the 2nd resistor (i.e. one in parallel) closes loop if any contact other than EOL contact opens? Do you not need to have a resistor in parallel across each contact within that zone?

No, it is looking at the 2 resistors to see what reading its getting on the loop.

The way it works is the with everything closed the panel sees 4K7.
A device open 9K4.
If the tamper is open is sees 000.

With single end of line if the sensor is open it sees nothing, closed it sees 4K7.

Waesfjord wrote: »

In SPC, it gives options for use of many different resistors for single and dual setups (E.g. single as 1k, 1k5, 2k2, 4k7, 10k, 12k, then for dual 1K/470, 1K/1K, 1K0, 2k2...all the way through options up to 10k). Why so many options, and is 4k7/4k7 just a standard people follow?

That is to help with take overs.
Another installation may use a different value resistor.

Waesfjord

altor wrote: »

No, it is looking at the 2 resistors to see what reading its getting on the loop.

The way it works is the with everything closed the panel sees 4K7.
A device open 9K4.
If the tamper is open is sees 000.

With single end of line if the sensor is open it sees nothing, closed it sees 4K7.
.

I had in my head a two wire requirement only for dual EOL, with the 2nd resistor (in parallel) only across the last contact, hence my query. So what you need is 3rd cable to bridge resistor across across all the contacts in zone, so if any contact opens within zone, then loop closed only by passing through 3rd wire & hence 2nd resistor, right. :rolleyes:

altor

Waesfjord wrote: »

I had in my head a two wire requirement only for dual EOL, with the 2nd resistor (in parallel) only across the last contact, hence my query. So what you need is 3rd cable to bridge resistor across across all the contacts in zone, so if any contact opens within zone, then loop closed only by passing through 3rd wire & hence 2nd resistor, right. :rolleyes:

Correct.
The main side to be worried about is the alarm side.
Once this is functioning an intruder would have to be in your home in most cases to tamper with a device.