Scantronic 335 detector

[Guest bgd]

I am having some issues with Scantronic 335 detectors,connected to 9752 panel.

The keypad is showing dc aux power error,which I am unable to clear.

I have been given 5 of these detectors by a friend and they are in "as new" condition apperience wise.

I have connected these without any EOL / FSL resistors,so used closed circuits wiring method.(black and red to a zone, white to 12DC, green to 0V, yellow and blue to global tamper loop, orange to test connections).

Each detector is connected to it's own zone.

How one can test the detectors whether they are functioning properly, what should be resistance value between 0V and 12VDC connections?

9752 Panel shares Zone terminals ie for 8 zones there should be 16 terminals, but the panel has 12 instead.I connected black wire from Pir1 and Pir2

to shared (middle)terminal for Zone1 and Zone2, red from Pir1 to Zone1, red from Pir2 to Zone2 etc. could someone confirm this is correct please?

Lastly could someone advise what is the correct wiring for Bentel TS100 bellbox

to this panel, I connected it according to it's instructions and I am getting sounder tamper error on the keypad's display.

Providing the detectors are proved faulty, could someone recommend good detector for a domestic installation (classic 3bed semi,no pets) and of similar size or smaller to Scantronic 335.

Thanks in advance!

[Service Engineer]

dc aux power error

Has the AUX fuse blown..?

what should be resistance value between 0V and 12VDC connections?

Should be VERY high, if not Infinate.

9752 Panel shares Zone terminals ie for 8 zones there should be 16 terminals, but the panel has 12 instead.I connected black wire from Pir1 and Pir2

to shared (middle)terminal for Zone1 and Zone2, red from Pir1 to Zone1, red from Pir2 to Zone2 etc. could someone confirm this is correct please?

Sounds ok to me.

Lastly could someone advise what is the correct wiring for Bentel TS100 bellbox

Never come accross one, but what are the Terminals marked as on the Bellbox..?

[Guest bgd]

Thanks for your quick reply Dave, much appreciated!

Yes the Aux fast fuse has blown, tried replacing it and it gets blown immediately, so I have feeling there is short circuit somewhere on the detectors, however I checked each of them last night and double checked all wires are looking good.

I measured resistance between 0 and 12V DC on the PIR's wires and I was getting over 700k on each one apart from one or two of the detectors where meter reads 40-50k? Is this causing the aux fuse to blow?

I have done new CQR 8 core all in wall conduit wiring, so I know the cables are ok.

Do you reckon I possibly have a duff detector or two?

I will post the terminal markings from the Bentel TS100 bellbox once I get back home.

[Service Engineer]

Yes the Aux fast fuse has blown, tried replacing it and it gets blown immediately, so I have feeling there is short circuit somewhere on the detectors, however I checked each of them last night and double checked all wires are looking good.

I measured resistance between 0 and 12V DC on the PIR's wires and I was getting over 700k on each one apart from one or two of the detectors where meter reads 40-50k? Is this causing the aux fuse to blow?

The fact the fuse blows immediately when you connect power to the detectors is indicating that there is a short somewhere, so make sure you have wired all the detectors the same way. The resistance readings you have all seem ok to me, which leads me to think that the short is only created when the sensors are actually powered up.

Take the time to ensure all the sensors are wired correctly at the detector. Then power up each sensor one at a time.

[Guest bgd]

Dave,

Here are Bentel TS100 bellbox connections as per the install guide.

+H positive Hold off supply

-H Negative Hold off supply

RTN - Negative tamper return

-R - Negative siren / strobe trigger (if connected to ground the horn and stobe will activate)

ENG - Optional engineer input, if connected to positive , it will prevent automatic activatiopn of siren by tamper and will open the tamper circuit (I gues this is to be used while installing / programming the system to avoid constant siren sounding)

BATT- battery link

ST- if connected to ground only strobe will activate.

I connected the bell to 9752 panel as follows:

+H Positive Hold off supply from bell to 12V AUX on the panel

-H Negative hold off supply from bell to 0V on the panel as well as linked to C1 and C2 as per 9752 wiring diagram.

RTN negative tamper return from bell to TR terminal on the panel

-R negative siren / strobe trigger bell side connected to NO1 output on

the panel side

optional ENG input not connected

Batt linked to bell's dedicated batt terminal

ST - not connected

Did I get anything wrong here?

The bell did not sound even once as yet (however it's new and tested working).

I will try and power up the detectors one at a time as per your advise and let you know the outcome.

Thanks again!

[Truss and France]

Hello

What size screws have you used to fix the detectors? (try using counter sunk screws instead of round head) make sure their not touching the detector circuit board as this might cause a short across your+ and - connections. Try powering up the panel without PIRs connected, if the fuse is OK then connect PIRs one at a time until the fuse blows, this will confirm which detector has a short on it.

Good luck

[Service Engineer]

Did I get anything wrong here?

The bell did not sound even once as yet (however it's new and tested working).

Looks like you have wired the bellbox up correcty. The AUX fuse being blown may explain why it hasn't worked yet.

I will try and power up the detectors one at a time as per your advise and let you know the outcome.

And do the same with the Bell too, incase the short is there. Also as suggested above check and ensure the detector backplate fixing screws aren't making contact with the detectors PCB when it's in place.

[JB_]

Your readings as Dave says are fine for resistance but don't forget to test between your 12v+ and your zone/tamper wires, quite possibly a short there could blow the fuse too. If it is a faulty pir then always make sure your red test lead is on 12v too, most pir's are protected against reverse polarity so you may well get different readings across 12v and 0v with your leads reversed.

[Guest bgd]

Thanks guys, very useful info!

I disconnected 0V & 12V DC for PIR's, AUX fuse is intact and tested keypads,internal and external sounders all working fine so as suspected the problem is definitely with PIRs.

Could not check these tonight as I did not want to disturb my neighbours (if I connect ENG bell terminal to it's positive +H,will this stop the siren when testing and working in the installer mode?).

As these Scantronic PIRs are not brand new I am a bit sceptic about them and may look to replace them, any recommendations? I was thinking of Texecom Prestige Compact IR model,are these better then Scantronic 335 Duals?

regards

[Guest]

Pass on the ENG feature but the Prestige IR is a very good detector. I would recommend them anyway, but if it's a choice between those and some second hand detectors then the Prestige get some more bonus points.