PC5204

[jasonreg]

How do you know when to add an additional power module such as the PC5204 or similar?  I have between 30 and 32 zones planned for my current Power Series 1832 panel, including a wireless module, three PC5108 expansion modules and four keypads.  I do not have anything hooked up to the PGM outputs right now.  I am using approx. 19 or 20 sensors which are drawing power.
 
Thx

 

[RAL]

I'm not an expert on the DSC 1832, but here is what I see from digging through the manual.
 
You need to add up the maximum current requirements of all the devices that draw power from the Keybus, PGM and AUX outputs and compare that to the maximum output capability of the panel.  This would include keypads, expansion modules like the PC5108, and things like smokes and PIR detectors that are drawing power from the AUX power terminals. 
 
There is a table in the DSC 1832 manual that gives the current requirements for the various supported DSC devices.  You will have to consult the manuals for smokes, PIRs, etc separately to get their current requirements.
 
One section in the DSC manual says that the AUX+ output is capable of providing 700 mA.  Above that, you need an additional power supply.  A good rule of thumb is to not push it right up to the maximum, but to stay below 80%, which would be 560 mA.
 
Another note in the manual says "current draw from Keypads, PGM Outputs and Aux circuits must not exceed 550 mA."    I'm not sure why it specifies 550 mA when elsewhere the manual says 700 mA, unless they are derating things for you according to the 80% rule.
 
For sirens and screamers, you need to add them up separately, as the BELL outputs have a separate 700mA maximum current limit.

 

[RAL]

I am using approx. 19 or 20 sensors which are drawing power.
 
Thx

 
When you say you are using sensors that are drawing power, do you mean wired sensors like motion detectors, or just door and window contacts?  A motion detector is something you need to count as drawing power.  A door or window contact does not get counted in the power calculation.  And although the wireless receiver needs to be counted, the wireless sensors themselves do not get counted since they are running on their own batteries.

 

[jasonreg]

Hi RAL, thx for the reply - yes I am only counting things like PIRs, glass breaks, smokes and CO detectors.  I will break out the calculator.
 
Much appreciated.

 

[jasonreg]

So - I am not sure why this surprises me based on other things I have found in this house but I am already over the recommended draw if I am doing this right.  To confirm, should I be using the max draw (i.e. device in alarm) for this calculation or the stand-by draw.  For everything at max I am at 978mA already.  I am planning on adding a few additional items with high draw (specifically two PTK5507 Touch LCD keypads) at 300mA each as a few Glass breaks and additional PIRs.
 
What should I be adding to the panel?  I see a PC5200 board (I can add up to 4) each giving a full 1A each of avail draw or I can add a PC5204 again giving 1A but it looks like I can add only one of these.  Am I tracking correctly?

 

[RAL]

Yes, you really need to use the maximum power numbers for each device in your calculation.  When the system is in alarm mode and everything is demanding power simultaneously, it must be able to supply enough power for all of them.
 
I'm not familiar with the PC5200 vs PC5204 power supplies beyond the quick read I did of the manuals.  But what I came away with is that you can have 1 PC5204 plus up to 4 PC5200s connected.  The difference between them is that the PC5204 gives you 4 high current controllable outputs.  So if you wanted to turn on a device that requires high power in some events, but not others, the PC5204 can do that for you.  The example they give shows a bell or siren.  If all you want to do is provide power for keypads or PIRs, then a PC5200 is all you need.

 

[jasonreg]

OK - that all makes sense - so it looks like min one if not two PC5200s will be required.  In that light, each PC5200 requires its own transformer, then it's own battery back-up as well.  Are plug-in transformers or ones hardwired to the electrical panel preferable?  Can one use a UPS instead of alarm batteries or should I really just add another enclosure and put the power expansion cards + batteries in there?

 

[RAL]

I prefer a plug-in transformer, as they are inexpensive, easy to replace, and make it easy to meet all the electrical code requirements.  Just make sure you get one that has the proper ratings of 16.5V and 40VA.
 
A UPS isn't a good idea.  When the power goes out, you will be converting the 12V from the UPS battery to 120 VAC, and then step it down to 16.5V and convert that back to the 12 VDC that the alarm system requires.  It's more efficient to run the alarm system off its own 12V battery, and that will translate to a longer time that it can last in a power outage.
 
I would add the extra enclosure if you need the space and put the batteries and expansion parts in there.

 

[jasonreg]

Got it - thx RAL.