MattH

Thinking it through, I guess NC and NO being inverted would explain why it worked with COM connected to positive and HOFF connected to NO.

I used a length of cat5 to bench test the box, but otherwise all the wiring is from 1988. The Chubb box is now mounted on the wall outside in place of the old box and tested ?

Yeah, picking this up as I go along, but that was my reckoning too when measuring the voltage across positive and NC/NO when set vs triggered with com to negative. Ignore the wire colours as is the cat5 I used to bench test but here's a pic of each end and working...

Got there in the end! You were right that COM needed to be negative, however HOFF then needed to be connected to NC rather than NO. Strobe also working when connected to NC. Don't know if it will carry on flashing after an alarm but I can live with that. Not sure why the connection in the panel marked strobe behaves as it does but not any use with this bell box. Many thanks again for your help, MrHappy ? . I don't think I'd have got there without the pointer. Cheers Matt

It's possible. I only know that the panel was installed by Chubb in 2010, and they connected it to the existing 1988 bell box. Looking in the old bell box, the strobe is actually standalone, and wired directly to the panel across STB and positive. I'll have another play with it later on.

Thanks again for the suggested wiring MrHappy - finally had the chance to try it today... Initially it didn't work, but after I connected COM to positive rather than negative the sounder now works as it should. No joy with the strobe though. The only time the strobe flashes is for about 10 seconds after the alarm sets, but it doesn't then flash when the alarm is triggered and the siren is sounding. For some reason there's a trigger from STB in the panel for those ten seconds after the alarm is set, but it doesn't happen when the alarm is triggered, if that makes sense. Any thoughts? If it's any help I looked at the back of the PCB of the bell box and it is manufactured by Elmdene... Cheers Matt

Splendid - thanks MrHappy ? It'll likely be the weekend now, but I'll give it a go and let you know how I get on. Cheers Matt

Ah ok, thanks, a false assumption then. Since there's nothing I can find on the Chubb Delta 7 box itself, does the wiring look like it might reasonably be correct for my PX 48i - and in particular are BELL/HOFF interchangeable terms? I did try putting a wire instead of the resistor between NC & + but it wasn't happy. Cheers Matt

So, a fun afternoon playing around with this but no cigar yet! I found the diagram below on the Internet which is to connect a "Deltabell" to my control box. I'm thinking this may be the company that manufacture the Chubb "Delta 7" box - the connections are the same except that on my box the BELL connection in the box is labelled HOFF - I assume it's the same thing? I didn't have a 4K7 resistor so will order one and hopefully that will do the trick. Thanks Matt

Great - thanks for the advice - I'll give it a go over the weekend!

Thanks for the reply... I've attached a couple of pics of the connections in the old bell box. There doesn't look to be a relay in there, and there is a resistor in the control unit in-line on the yellow cable (yellow and blue look to be sounder tamper). As you say there ate 6 wires going to the old bell box - yellow/blue tamper, green/wht go directly to the strobe, and red/black going to that curcuit board.

Hi there I have a Chubb/Guardall PX48i control unit that was fitted in 2010 by the insurance company following a burglary, but connected to a much older (the battery inside was dated 1988!) bell box. The control panel started showing failed battery self test recently so have replaced the batteries in the controller and bell box and all is well again, however, it got me thinking that a newer bell box would be a better deterrant. I found a 2017 Chubb Delta 7 box on ebay which has arrived. The wiring doesn't bear any resemblance to the older bell box though, and I was hoping someone might be able to help me with wiring up the new one. I've attached a picture of the control unit connections and have drawn the bell box connections underneath - if anyone could join the dots thta would be great! I've also attached a photo of the bell box connections in case the drawing is unclear. It looks like only TAMP, 0v, 12v, STR and HOFF were connected wherever the bell box came from. Any help much appreciated! Thanks Matt