Contacts in parallel?

[beelzerob]

I want to monitor my smoke alarms, which are a simple form-c relay. I don't think I have enough digital inputs to monitor them all separately, so I might as well break them down into floors. So if I hook, say, 5 of them in parallel on a single digital input of my Secu16 or zeebox250, will that work? So if any one of them closes, it'll signal?

 

[Lagerhead]

If I hook, say, 5 of them in parallel on a single digital input of my Secu16 or zeebox250, will that work? So if any one of them closes, it'll signal?

Don't see why not.

 

[mustangcoupe]

If I hook, say, 5 of them in parallel on a single digital input of my Secu16 or zeebox250, will that work? So if any one of them closes, it'll signal?

as long as all they are is relay outputs, YES

 

[beelzerob]

They are form c relays, so no problem.

For my education, what other form of outputs could they be, and why would that cause a problem?

 

[WayneW]

They are form c relays, so no problem.

For my education, what other form of outputs could they be, and why would that cause a problem?

The "form" tells you the type of contacts a relay has.
http://wiki.answers.com/Q/What_would_a_1_F...Form_B_relay_be

The risk is if they are not relay contacts, you could hurt something. Instead of a relay, they could be some solid-state equivalent, such as a transistor or triac, which may not like having a signal fed into its output.

 

[beelzerob]

Oh, ok. So if it's mechanical, then it's ok? So for instance, multiple door/window contacts would probably also be ok, as they are magnetic reed switches.

 

[BraveSirRobbin]

You have to watch if the 'switches' or 'relays' you are using are normally closed or normally open before deciding to series or parallel them.

 

[beelzerob]

Well, that makes sense. Only if they're all NO will it work, right? fortunately the smokes and heat detectors are all that kind.

 

[BraveSirRobbin]

Well, that makes sense. Only if they're all NO will it work, right? fortunately the smokes and heat detectors are all that kind.

Yes, but you also mentioned above:

multiple door/window contacts would probably also be ok

Which is why I posted that warning.

 

[beelzerob]

Ya, my mistake...I meant the kind of sensor used on this (NO magnetic reed switch), not actually doors and windows. Those wouldn't be so useful in parallel.

Although I plan to do my windows in serial, since each window and each sash is wired. That way I can monitor just the whole room.