twin sounders

[Guest Alan]

Hello,

I've a Scantronic 9800 which was until recently connected to two separate alarm boxes containing sirens connected in parallel and microswitch tampers connected in series. This all worked fine.

I've now replaced the above alarm boxes with two new SAB units but can't figure out how to wire the tamper circuits.

On the old system the tamper circuit was simply a wire from the 0v connection on the control panel, passing in series through the two microswitches ( one in each alarm box) and back to the TR connection on the contol panel.

The new SAB units have negative hold off supply and a tamper return connections but if I connect these in series to the 0v and TR connections in the control panel, I get a tamper fault.

Would appreciate any suggestions.

Alan

[mr silcox]

first take the 0v -hold off to the first sab from the 0v in the panel

take the tamper return from the first sab to the 2nd sab 0v hold off

then from the 2nd sab tamper return to the control panel (tr)

this give you the added advantange that if some one opens the first bellbox it will ring both bellboxs

so when installing compleat the first bellbox (cover on, all tampers clear,)before puting lid on the other .

if you dont becase the 2nd sab is not geting any 0v it ring on its backup battery

good luck

[JB_]

Is it just the SAB unit that you've replaced or have you replaced the whole bell box with diffrent models. (2 same obviously) Only reason i ask is SAB's generally work as Mr Silcox says below but most bellbox's have a diffrent way of wiring than that, which is detaild in the instructions you get with them. (must admit its been a while since i saw a standalone SAB unit)

Maybe let us know exactly what you bought, and especially if it was a DIY place you got it from. (/me spits)

[Guest Guest]

>>>Mr Silcox / JB_

Thanks for your suggestion. I've tried wiring exactly as you said but I still end up showing a tamper fault at the main control panel.

As a test, I've connected each SAB individually and they work fine but as soon as I try to connect both boxes with the tampers in series the control panel shows a tamper fault. The SAB units are made by Elmdene but their wiring diagram is only for a single unit operation. On their insructions it says the tamper return is "negative only (open collector with 100R resistor in series)" Could it be that this type of anti tamper cannot be connected in series.

To get the system to work, I've had to connect the anti tamper circuits in parallel but this means, as you said, that only the bell that is tampered with rings rather than both bells.

Would appreciate any further advice / suggestions

[JB_]

Must admit we've never used any Elmdene boxes so im not too familiar with them, but wiring them the way you say could result in the control panel not knowing if any of the boxes has been tampered, although the outside bell that was tampered should still ring.

Why not try speaking to the Elmdene technical people?

Looking on Elmdene.co.uk i've found this:-

ELMDENE INTERNATIONAL LIMITED

Rodney Road, Fratton, Portsmouth PO4 8SS United Kingdom

Tel: +44 (0)23 9273 9412 Fax: +44 (0)23 9281 1631

e-mail: sales@elmdene.co.uk

[Guest Alanh]

>>>JB

Thanks for the info on Elmdene, I'll get in touch with them.