Class A loops

[Alwayslearningelec]

Does every fire alam device get a loop( out and back) with andressable class A system or is it certain devices such as initiating, signaling etc.? Thanks

 

[nhfire77]

Does every fire alam device get a loop( out and back) with andressable class A system or is it certain devices such as initiating, signaling etc.? Thanks

Too many variables to answer yes or no. Someone competent must design the system. You will not see (at least not if it was compentnently designed) a 'class A system'. The spec may call for one type of circuit class A and others are B.

 

[ron]

Depends
You could have Class A or B initiating, signaling or notificaiton. You can mix or match..

 

[Alwayslearningelec]

Too many variables to answer yes or no. Someone competent must design the system. You will not see (at least not if it was compentnently designed) a 'class A system'. The spec may call for one type of circuit class A and others are B.

But can it be ONLY class A and not mix? Thanks

 

[Alwayslearningelec]

Too many variables to answer yes or no. Someone competent must design the system. You will not see (at least not if it was compentnently designed) a 'class A system'. The spec may call for one type of circuit class A and others are B.

What do you mean ' you will not see a class A system"

 

[nhfire77]

What do you mean ' you will not see a class A system"

There is no such thing as a class a system. You may be required to have class A NACs, SLCs etc, but it may not say class A rs485, bacnet, comm bus, SBUS etc. circuits.

If someone told me to do a class A system, I'd ask to what degree? It's too vague. It's not a description, it's a generality. No one specs a 'class a' fire alarm.

 

[ron]

But can it be ONLY class A and not mix? Thanks

Depending on its interpretation, they may be expecting Class A Initiating, notification and signalling line circuits.

Sometimes depending on the application, I specify Class A initiating, Class A signalling and Class B Notification.

 

[gadfly56]

Love the DOD!

Love the DOD!

Not long ago I completed the design and installation of a "Mass Notification System" for a near-by DOD facility. For half the building. Voice evac, the works. Every stinkin' circuit was Class A. Across the hall, the other half of the building was off an old Notifier panel, all Class B, and most of it non-operational. Go figure. The base AHJ twigged onto the situation, and we landed all the conventional circuits onto our panel via suitable modules (still Class B!), but the dichotomy made my head spin hmy:.

 

[Alwayslearningelec]

The spec reads:

The fire detection and communication system shall be an integrated system of the addressable multiplexed type, comletely supervisedf, Class "A". Non- addressable alarm initiating, supervisoty and status monitored devices shall be integrated into the fore alarm system via addressable interface modules.