Wiring NO contacts with NC DSC832

[Jim Sumpter]

I am finishing the wiring on my DSC 832 and am ready to jump into
programming. The manual states that I can set it up as being either a
NO or NC system, but has nothing in it about using both NO and NC
devices simultaneously. There is a diagram about using EOL resistors
showing both NO and NC contacts on the same zone, but in my case, that
didn't help at all. All of my devices are NC except for my door
contacts, and I am using EOL resistors on every zone. I had planned to
wire the 3 NO contacts to 3 different keypads, with the contacts being
the only device wired to the keypad zones. In the future, I would like
to wire some NO window contacts together on their own zone. So, my
question is, do I wire them up NO using an EOL resistor wired parallel
and not worry about the system being programmed as NC? I figured if I
did this it would constantly be in alarm. Also, for the window
contacts, would I wire them all parallel with a EOL parallel at the end?
I guess the resistor is the key to doing this? If the NO contact
closes, it would send the current through the 5.6k resistor, showing the
panel a violation. Hmm, did I just answer my own question?? Thanks in
advance for any tips you might be able to provide.

Jim

 

[Frank Olson]

I am finishing the wiring on my DSC 832 and am ready to jump into
programming. The manual states that I can set it up as being either a
NO or NC system, but has nothing in it about using both NO and NC
devices simultaneously. There is a diagram about using EOL resistors
showing both NO and NC contacts on the same zone, but in my case, that
didn't help at all. All of my devices are NC except for my door
contacts, and I am using EOL resistors on every zone. I had planned to
wire the 3 NO contacts to 3 different keypads, with the contacts being
the only device wired to the keypad zones. In the future, I would like
to wire some NO window contacts together on their own zone. So, my
question is, do I wire them up NO using an EOL resistor wired parallel
and not worry about the system being programmed as NC? I figured if I
did this it would constantly be in alarm. Also, for the window
contacts, would I wire them all parallel with a EOL parallel at the end?
I guess the resistor is the key to doing this? If the NO contact
closes, it would send the current through the 5.6k resistor, showing the
panel a violation. Hmm, did I just answer my own question?? Thanks in
advance for any tips you might be able to provide.

Normally closed loops use switches that are *closed* when all the windows
and doors are. That means that when the magnet and the switch are aligned,
the switch is closed. If you're going to incorporate resistors in these
types of loops you would have to put them in *series* with the switch. The
beauty of using a multi-zone panel is that you'll be able to have each
switch and device on its own zone. If you use switches with built in
magnets you have the most secure setup there is. On an end-of-line
supervised loop programmed as a "burglary" zone, a short in the wire (which
could happen if it's cut) would show up as an alarm and an "open" would
also. If you incorporate multiple contacts in series in a normally *closed*
loop (or parallel in a normally *open* one) with a single end-of-line, you
could conceivably wind up with one of them being compromised without
affecting the loop. I've seen this happen in older commercial systems with
surface type contacts that employ screw terminals. It's pretty simple for
anyone with some knowledge of how a system works to bypass these. If,
however, that same contact was home run to it's own zone and employed a
built-in end-of-line, a short across the terminals would show up as a fault
on the keypad which would prevent you arming the system until you took care
of it. Whether you decide to use "normally open" or "normally closed"
contact switches is entirely up to you. Most of the alarm suppliers sell
the "normally open" type (which are for use with closed loop circuits). The
"normally closed" contacts (used with end-of-line supervised loops) are sold
as well but aren't as popular. In Canada, ULC certified systems use
contacts that have *both* normally closed and a normally open terminals and
they're wired to the control a whole lot differently.

One more thing. The guys working for the suppliers will often hand you a
"closed loop" contact when you ask to buy a "normally closed" one and most
alarm installers I chat with make the same interpretation as well.


--
Frank Olson
http://www.yoursecuritysource.com
Free listings for qualified dealers and industry professionals
You can read the ASA FAQ at
http://www.yoursecuritysource.com/asafaq.htm

 

[Jim Sumpter]

Normally closed loops use switches that are *closed* when all the
windows and doors are. That means that when the magnet and the switch
are aligned, the switch is closed. <the rest snipped>

Thanks for your time and reply Frank. I understand how the NO and NC
switches work, and also understand EOL resistors. I may even have a
better understanding of the two after your message, but could you help
me with my original question? Please don't take this the wrong way!

Thanks again,

Jim

 

[Jim Sumpter]

Thanks for your time and reply Frank. I understand how the NO and NC
switches work, and also understand EOL resistors. I may even have a
better understanding of the two after your message, but could you help
me with my original question? Please don't take this the wrong way!

Thanks again,

Jim

Ok,I re-read my original message and think it might be a bit much for most
people to read, so I will try to consolidate it:

I have a DSC 832 panel, programmed to use NC devices with EOL resistors at
each EOL device. I need to attach 3 NO door contacts to 3 different
keypad. The NO door contacts will be the only devices on each keypad zone.
Will wiring them as NO with an EOL 5.6k resistor parallel work or will I
have an immediate alarm when I fire it up?

So, panel programmed as NC with EOL resistors, door contacts NO. Will it
work?

Frank, I think you assumed that I am an average DIY'er. I would like to
think that I am a average DIY'er that does his homework before asking the
stupid question...

Thanks once again,

Jim

 

[G. Morgan]

alt.security.alarms

Frank, I think you assumed that I am an average DIY'er. I would like to
think that I am a average DIY'er that does his homework before asking the
stupid question...

Why don't you just power the damn thing up and experiment with it,
before asking stupid questions?


-Graham

Remove the 'snails' from my email

 

[Frank Olson]

Ok,I re-read my original message and think it might be a bit much for most
people to read, so I will try to consolidate it:

I have a DSC 832 panel, programmed to use NC devices with EOL resistors at
each EOL device. I need to attach 3 NO door contacts to 3 different
keypad. The NO door contacts will be the only devices on each keypad
zone.
Will wiring them as NO with an EOL 5.6k resistor parallel work or will I
have an immediate alarm when I fire it up?

If you program the panel for EOL supervision enabled, the system will
*always* see the 5.6 k resistor as a "normal" condition. In other words, if
all you do is put a resistor at the end of your keypad zone wire, nothing
will happen. When you program the keypad zone as any "burg" option (delay,
perimeter, or interior) any time the panel *doesn't* see the EOL the zone
will "fault". If the panel is armed, it will result in an alarm (after the
appropriate entry delay you've programmed expires if the keypad zone is a
"delay" loop). A normally closed loop uses contacts that are actually
considered "normally open". They *close* when they're in the presence of a
magnetic field. You have to wire these type of contacts in *series* with
the resistor. If you're using "normally closed" contacts, they will in fact
"open" in the presence of a magnetic field. You have to wire these type in
*parallel* with the resisitor.

So, panel programmed as NC with EOL resistors, door contacts NO. Will it
work?

When programmed as a burglar loop, as long as the panel *sees* the EOL
resistor, it will consider the loop "normal". When the resistance is
*shorted* or the loop is *opened*, it will see the zone as "faulted" and
will respond accordingly depending on the status of the panel (armed or
disarmed).

Frank, I think you assumed that I am an average DIY'er. I would like to
think that I am a average DIY'er that does his homework before asking the
stupid question...

There are no "stupid" questions except the ones to which the answers are
printed in big block letters in the manual. People that ask the "stupid"
questions have never read the manual because they either don't have it or
are too lazy to do so (I have no patience with the latter and am pretty
forgiving of the former). You obviously *have* read the manual and just
needed to get some clarification. The DSC manual was *not* written from a
"do-it-yourselfer's" viewpoint so your confusion is understandable. I'm
pretty sure it was actually written by a French-Canadian Engineer and
translated to English by some Chinese guy (kidding). )


--
Frank Olson
http://www.yoursecuritysource.com
Free listings for qualified dealers and industry professionals
You can read the ASA FAQ at
http://www.yoursecuritysource.com/asafaq.htm

 

[alarman]

Jim Sumpter wrote

Frank, I think you assumed that I am an average DIY'er. I would like to
think that I am a average DIY'er that does his homework before asking the
stupid question...

If that were true, why didn't you just try it for yourself?
js

 

[Jim Sumpter]

:

When programmed as a burglar loop, as long as the panel *sees* the EOL
resistor, it will consider the loop "normal". When the resistance is
*shorted* or the loop is *opened*, it will see the zone as "faulted"
and will respond accordingly depending on the status of the panel
(armed or disarmed).

Thank you so much again Frank. I appreciate the help! Glad to see this
newsgroup is good for more than Bass bashing.

 

[Jim Sumpter]

alt.security.alarms



Why don't you just power the damn thing up and experiment with it,
before asking stupid questions?


-Graham

Remove the 'snails' from my email

I would at least like to get the wiring correct before jumping into the
programming... Thanks for the reply.

 

[Frank Olson]

:




Thank you so much again Frank. I appreciate the help! Glad to see this
newsgroup is good for more than Bass bashing.

Fishing stories are good too!! ;-))

 

[R.H.Campbell]

Sir, is there a particular reason why you are using NO contacts on burglar
zones. This is somewhat unusual in my experience, since NO zones are usually
used with smoke detectors and supervised with the EOL resistor. With all due
respect, why make work for yourself; why not just go buy NC contacts and be
done with it....

Just curious...

RHC