a blast from the 90s .....

[iain maoileoin]

I have a inherited a security installation.  The main board is U/S.

I was planning to dismember the system and replace the controller with say a Honeywell Galaxy system.  There is already a board like that elsewhere in the building.

 

I would like to find out a little bit about the unit and the wiring before I take it out.  It appears to be an ancient Thorn security system. Photo attached.

Some sensors are new, some are ancient.

The board appears to use 6 wires per device/circuit, with 2 for power and ground, so I guess 2 for detector (CCTx) and 2 for the anti-tamper (A/Tx).

I have not yet taken a sensor to bits, so I have no idea what is in it.

I know the colours mean nothing.  In this install Blue/Yellow appears to be power and ground,

So I guess are red and white zone (CCT)  and green and black anti-tamper (A/T).

Is this likely?

 

How the blazes do I wire those sensors up to a more modern board like a Galaxy that seems to have only 2 wires per zone/area.

 

 

 

 

Any input appreciated.

[james.wilson]

Looks like a scantronic 9800?

But I haven't seen one in years

 

If so uses double pole wiring (no resistors) 

You will have to add the resistors but given the age your probably going to replace tge sensors too

[MrHappy]

44 minutes ago, iain maoileoin said:

I have a inherited a security installation.

 

4 pirs, 1 door contact, 1 keypad, 1 speaker ,1 external sounder.

 

to renew everything is at most a days work & I've allowed extra as its a secret nuclear bunker

 

being big head.... I'd expect you'll spend the week end at it ?

 

Edited March 31, 2021 by MrHappy

[sixwheeledbeast]

Use a panel that can do double pole or just replace the devices as above.

Putting resistors in old devices is often asking for trouble.

[GalaxyGuy]

1 hour ago, iain maoileoin said:

How the blazes do I wire those sensors up to a more modern board like a Galaxy that seems to have only 2 wires per zone/area.

 

You can set the Galaxy zones to N/C like your old system. Each zone can be programmed individually on Dimension and Flex.  I would recommend reconfiguring with new sensors or the addition of resistors (I've never had a problem adding 2x 1k resistors in existing sensors for double balanced zones).  

 

It may be worthwhile changing the PIR's anyway, as they're very cheap and the pyroelectric element in the sensors do deteriorate over time reducing their sensitivity.

[iain maoileoin]

Mr Happy: Close, Nae keypad - somebody stole it!  But since the place is secret I have lost it and need an extra day to hunt and find it.  I suspect a happy week at and hour here and there will do - assuming the existing wiring still forms a circuit.

GalaxyGuy: Thanks for the comment on Dimension and Flex.  The kit is V old and as you say new PIRs are not expensive.   I was more interested in the use of the three circuits (power,zone and tamper) rather than the 1-2 they use now.

[GalaxyGuy]

2 minutes ago, iain maoileoin said:

Mr Happy: Close, Nae keypad - somebody stole it!  But since the place is secret I have lost it and need an extra day to hunt and find it.  I suspect a happy week at and hour here and there will do - assuming the existing wiring still forms a circuit.

GalaxyGuy: Thanks for the comment on Dimension and Flex.  The kit is V old and as you say new PIRs are not expensive.   I was more interested in the use of the three circuits (power,zone and tamper) rather than the 1-2 they use now.

 

With zones set to NC, you then consume two zones to cover zone and tamper circuits. This is a bit of a waste of zones when you can cover the tamper open/short circuits with the addition of resistors.

[MrHappy]

6 minutes ago, iain maoileoin said:

The kit is V old and as you say new PIRs are not expensive.

 

the controls date back to 1989 ish

 

6 minutes ago, iain maoileoin said:

 I was more interested in the use of the three circuits (power,zone and tamper) rather than the 1-2 they use now.

 

Tunstall where doing 4k7/2k2 EOL back in the late 80's

 

What you have a the moment is positive loop for alarm, a negtive loop for tamper & +/- to power a pir

 

then you can bodgengineer eol resistors on at the panel end to hang the old sensors onto the new controls, until your ready to replace

 

but its always prudent to spend 5 mins & measure the wiring before starting to rive the controls off the wall

 

 

[iain maoileoin]

38 minutes ago, MrHappy said:

 

the controls date back to 1989 ish  

 

agreed; the date of 27th Feb 1991 appears on the THORN install quote - with an all-in price of £1015;  Maint was £100 p.a. fixed price for 3 years.  What you find in old documents....

[norman]

Guessing a school or similar?