No need for a relay.

Wish people would read posts and not assume.

lol, your sure its not a Nova 2?

i relay isnt essential paul but usually best. Problems occur on the possitive voltage (if opened etc) if not dioded, and also may go high res or even alarm when sounding as it will drift up slightly from hard neg.

If it were me id use a relay. If i was bodging it id use a different value resistor.

lol, your sure its not a Nova 2?

Well OP said Oddy 3E

[quotei relay isnt essential paul but usually best. Problems occur on the possitive voltage (if opened etc) if not dioded, and also may go high res or even alarm when sounding as it will drift up slightly from hard neg.

If it were me id use a relay. If i was bodging it id use a different value resistor.]

Its a neg return, M`s hated it.

The early ones.

Was probs a M problem cos 9651`s never had this issue.

James you say you respect others opinions, trust me I have seen this fault and watched it carefully.

Even to the point of getting ladders out and swapping the feeds and not putting it on the docket so the end user wasnt charged.

EWD still SAB`s and shows a tamper.

Perhaps its me then, careing too much.

Thank you all for the replies and advice, just for my own curiosity, is this just a problem with the oddysey 3e or would this problem be common to all bell boxes.

its a voltage and cable size problem. As the 0v for the tamper return is sourced from the HO- when it goes into a alarm due to the current draw and voltage drop the 0v becomes slightly above 0v. this then affects the Tamper return and puts a slight positive voltage on the tamper return. Because the ref point has now moved it affects the zone.

If you use a relay or wire the swicthes straight into the panel it avoides this problem. You can also use a diode and a modified resistor value depending on draw / cable length, but easier to use a relay imo.

I've done it before with a relay (act 120L) Worked fine.

Simply use the tamper return the trigger the relay. Wire the resistor into the C/NC.

Edited January 4, 201115 yr by 9651

Well OP said Oddy 3E

Its a neg return, M`s hated it.

The early ones.

Was probs a M problem cos 9651`s never had this issue.

James you say you respect others opinions, trust me I have seen this fault and watched it carefully.

Even to the point of getting ladders out and swapping the feeds and not putting it on the docket so the end user wasnt charged.

EWD still SAB`s and shows a tamper.

Perhaps its me then, careing too much.

Definitely an early M problem with the 3e. First few we fitted i was up and down the ladder, checking the voltage at the bell as the return was fine. As mentioned above, as soon as the bell was triggered the rtn voltage drops slightly. The cut off on the early panels for the rtn was obviously too low. Think i've seen it in the tech notes somewhere.............

Trouble was the M and Oddy were the staple panel of choice.

Have to admit when the RED pcb was changed the problem went away.

But by then G-2 20/44`s were being used more by then.

Just remembered a job with a M750, had two Oddy 3`s one SAB one SCB no trouble.

However it was fully loaded and had another PSU as well. And I had flashed it on the test bench as well before I took it to site.

Strange the 9651 didnt find it an issue.

All seem to be fine now though.

Yeah come to think it was the red pcb ones (can think of a few out there with butchered bell box tampers lol)

2 other engineers fitted a 2000 today, had a quick look, was amazed they've ditched the plug on connectors, impressed!

Why have they ditched the 1000 now also? Seems a big jump form a 800 (3 nodes) to a 2000 with iirc 16 nodes?

They did that with the 800 too iirc.

Cutting down on stock/procucts.

Do seem to be pushing Scanny more imho.

Edited January 4, 201115 yr by Oxo