Electronic Alarms and Home Security Devices - Power supply question Vista 20P

I finally have all items for the alarm in my new house that is under construction and I have wired in a home run method for the following:

4 keypads ( 6270, 6160RF, 6160 & 6150)
5 wired door contacts
2 wired garage door contacts
3 wired motions
1 two wired smoke
1 four wired smoke
1 wired heat detector
1 wired carbon monixide detector
1 speaker driver
2 speakers
1 siren
2 wireless motions
5 wireless window/door transmitters
2 5804 bdv key fobs

Firstly, does the power supply provided with the system, 16.5VAC 25A sufficient to power this system or should I add an additional power supply?

Any suggestions, concerns etc on my overzealous plans with this system?

Hmmm, Add 'em up. Without having the specs in front of me, with the 4 keypads (one of which is a graphic keypad) and several system powered devices you probably are pushing past the 600ma current draw (remember; good engineering gives a 20% cushion).

Something cheap like one of the little ELK power supply cards will do the trick; just remember to bond the negative of the power supply output to the negative for your aux power on the main panel.

Thanks for the reply.

If I have this right then, the add on power supply doesn't "piggy back" onto the panel but rather I split up some of the devices and spread them out on the load contacts of each of the power supplies. Is this correct?

By bonding the negative side of each together what does this actually do?

Do some of the devices use the negative as a signal lead as well or does this just stabilize the whole system to insure all is properly connected to receive signals etc from the main panel.

I will order the additional power supply today.

Correct, you don't simply parallel connect the power supply to the aux power of the main panel (the voltage regulators in the two power supplies will fight each other). Look at the diagram in figure 6 on page 2-4 of the installation manual.

You will need to move up to a 40 VA transformer or better to power both the panel and power supply with a single transformer. Give the power supply it's own battery. In this case a giving both panel and PS a 5ah battery will be more than enough (otherwise, you lose the keypads that are being powered by the add on power supply if there is an AC power failure)

If the panel and the power supply are not bonded on the DC negative, you will get unstable behavior from the keypads and system as a whole.

Thanks for "dumming it down" for me. It is clear now, and I am slowly learning. I was going to get an additional box to hold add ons such as the 4204 relay board that I was going to use to control my garage door openers with the 5804bd keyfobs. I then would have a place for the new power supply and backup battery you recommended. I would assume it doesn't matter if I got another transformer similar to the one I have now to power the 2nd power supply or would it be better as you mentioned to just get a larger transformer to provide AC to both the power supplies.

I just thought of one last question ( yah right ) but is there any advantage to using a Zone Expander i.e. 4219 instead of zone doubling resistor's?
Once my house is finished construction, I won't be able to add any new wired devices as both levels will be finished and it will be way beyond my ability to run additional wiring once everything is closed up. I am up to 14 wired devices, excluding the smoke/heat circuit and some can be ran in series i.e. two overhead garage doors, two front entry doors etc. so all in all about 12 wired zones. As I understand it if I add a 4219 zone expander, I would have 6 free wired zones on the main panel and the additional 8 on the expansion panel, totaling 14 zones plus zone 1 for smokes. If I am correct which would be a surprize, using the zone doubling resistors, I would also have a total of 14 zones plus zone 1 for smokes.

Will the panel actually display 14 separate zones besides of course zone 1 for smokes, using the doubling resistors, onto my alpha keypads?

Thanks again for the great advice

A seperate transformer is really the better choice, but I've done both variations. The biggest advantages of the zone expander is simplicity, and the ability to locate the module remotely (it's essentially a keypad, in terms of wiring; a trick sometimes used to tie two stand alone systems into a single one).

The zone doubling resistors are effective and work well, but you have to keep track of what you are doing during the initial assembly, or you can spend a bit of time sorting out where you got turned around.

The keypads will display zones to the limit of the system capacity.

It will display all the zones regardless of whether it is a zone doubled or on a 4219. But zone doubling makes for a big hassle in the panel. I never do it, just add expanders, but that's just my opinion. I could be wrong.