Abacus Query

[Herman]

Is there such a system as an Abacus 12?

I've seen plenty of 6's, 8's, 15's and 72's but not sure about 12?

If so, does it use 2K2's and 4K7's in it's zone wiring?

I can only find reference to 3K9's and 8K2's in my Abacus manuals (none of which detail the 12).

Equally what kind of zone configuration would it be if C and T were linked, with the incoming pair then connected across A and CT?

[topalarms]

Yes there was an Abacus 12 and none of the Abacus used 2k2 & 4k7 resistors as far as I recall - 2-wire, 3-wire or 4-wire but too long ago to remember the zone configs, someone else might.

[antinode]

Is there such a system as an Abacus 12?

I've seen plenty of 6's, 8's, 15's and 72's but not sure about 12?

If so, does it use 2K2's and 4K7's in it's zone wiring?

I can only find reference to 3K9's and 8K2's in my Abacus manuals (none of which detail the 12).

Equally what kind of zone configuration would it be if C and T were linked, with the incoming pair then connected across A and CT?

Last question would be 3 wire with the tamper linked out by the sound of it. Abacus use 3K9 and 8K2 wired unconventionally. Never seen an Abacus 12 in the flesh but they do exist. Worked on quite a few 64's, 72's and 8/80's, generally very good panels for their era.

[topalarms]

3-wire to zone splitter module as well.

[antinode]

3-wire to zone splitter module as well.

True, though the T and C terminals shouldn't be shorted out if there is a splitter wired in.

The only way to check for sure is either to find the splitter, or check in the programming to see if the circuit in question has been programmed to split.

[Herman]

Please bear in mind I haven't actually seen the Abacus in question with my own eyes.

I tend to agree with your point about the three wire configuration.

With that in mind, there can't be a splitter connected as a splitter needs to be connected to A, C and T.

I'm going to have to go back to my guy and try and clarify where he thinks the oddball resistors are.

Just for my info, does anyone know the exact significance of terminals A+, A, C and T?

Why in 4-wire mode do they operate as straight forward alarm and tamper?

Why in 3-wire mode you're able to drop A+?

Why in 2-wire mode you're able to drop both A+ and C?

How does A, C and T relate to a splitter?

[The Arab]

Why in 4-wire mode do they operate as straight forward alarm and tamper?

Why in 3-wire mode you're able to drop A+?

Why in 2-wire mode you're able to drop both A+ and C?

How does A, C and T relate to a splitter?

From memory A is alarm ,A+ is a voltage out (so you don't need it if you use a 3 wire config as C becomes output),C is a common output,T is tamper

so in 4 wire ,T loops to C and A+ returns to A

in 3 wire ,T loops to C,C then goes through resistor to A (across alarm contact/relay)

in 2 wire ,T to A then become end of line (T to one leg of tamper other leg has one leg of resistor that goes to alarm contact/relay with other resistor his one goes to other side of contact/relay with wire that returns to A terminal)

So zone splitter doesn't need the A+ as works on resistors

All Abacus 12 panels were 3 wire

Hope this helps