Fire alarm

[Alwayslearningelec]

Now this is confusing. Isn't the SLC(for addressable system) the initiating circuit?

 

[infinity]

Now this is confusing. Isn't the SLC(for addressable system) the initiating circuit?

View attachment 2575812

If I remember correctly Class A is a return loop, Class B uses end of line resistors at the last device.

 

[Alwayslearningelec]

If I remember correctly Class A is a return loop, Class B uses end of line resistors at the last device.

Your correct. But they are SLC should be return and initiating should not be. I thought SLC was an initiating circuit.

 

[don_resqcapt19]

Your correct. But they are SLC should be return and initiating should not be. I thought SLC was an initiating circuit.

3.3.279 Signaling Line Circuit.
A circuit path between any combination of addressable appliances or devices, circuit interfaces, control units, or transmitters over which multiple system input signals or output signals or both are carried. (SIG-PRO)

My guess there is a SLC to a controller that is connected to multiple initiating and/or indicating devices.

 

[gadfly56]

Initiating Device Circuits (IDC) are used for non-addressable initiating devices; conventional pulls, smokes, heats, etc.