I have been carrying out some checks of my Scantronic 9448 control panel.

I have noticed that the cable that connects to the TR terminal, coming back from the external sounder, has a high resistance (0.6MΩ) between it and the 0V terminal of the control box when the TR cable is removed from the terminal.

Am i right in thinking that this should be 0Ω i.e. the 0V from the control panel is sent out to the sounder, through the tamper switch and back to the TR terminal?

If this is correct, to temporarily inhibit the tamper loop could i link the 0V terminal to the TR terminal at the control panel?

Ray.

it should be 0 volts not 0 ohms.

test between 12v pos and the TR and you should have a reading of around 12 volts dc

I am sorry but we cannot tell you what to do with the TR terminal in regards to linking out stuff

Edited March 18, 200719 yr by camerabloke

I have been carrying out some checks of my Scantronic 9448 control panel.

I have noticed that the cable that connects to the TR terminal, coming back from the external sounder, has a high resistance (0.6MΩ) between it and the 0V terminal of the control box when the TR cable is removed from the terminal.

Am i right in thinking that this should be 0Ω i.e. the 0V from the control panel is sent out to the sounder, through the tamper switch and back to the TR terminal?

If this is correct, to temporarily inhibit the tamper loop could i link the 0V terminal to the TR terminal at the control panel?

Ray.

i would take that reading again with both the ov and tr diconnected or otherwise measure the voltage between 12v and tr it should read approx the same as between 12v and 0v

too slow angus

too slow angus

yes but mines easier to understand lol

Thanks for your prompt responses.

Yes between the 12V terminal and the TR (cable) I have 13.22V. My 12 volt supply (measured across the 0 and 12V terminals) is 13.62V.

With both the 0V and TR cables removed I have infinity resistance across them.

I was under the impression that the tamper loop was the 0V being sent from the OV control panel, to the sounder and then back onto the TR (because the wiring diagram shows this cable as

I was under the impression that the tamper loop was the 0V being sent from the OV control panel, to the sounder and then back onto the TR (because the wiring diagram shows this cable as

Thanks for your prompt responses.

Yes between the 12V terminal and the TR (cable) I have 13.22V. My 12 volt supply (measured across the 0 and 12V terminals) is 13.62V.

With both the 0V and TR cables removed I have infinity resistance across them.

I was under the impression that the tamper loop was the 0V being sent from the OV control panel, to the sounder and then back onto the TR (because the wiring diagram shows this cable as