12 Volt power supply - is it all the same?

[Guest]

Hi all,

I am installing blinds powered by home runs to basement.
The Somfy 12 Volt power supply is 12 volts and 700+CAN$. Interesting that their 12 volt motors are all the same for power supply or batteries. The battery version just has a tube for 8 AA batteries. The control is RF built into motors.

Rollertrol suggested powering theirs from an RV battery and trickle charger.

Is there any reason why I would need the proprietary 12 volt supply from Somfy or would an RV battery work just fine?

[mrhappy]

Some considerations that may be relevant (if you ask me);

1) Are you able to say the distance of cable run and the gauge of wire?
2) How many motor units, how much current does each one take?
3) What size battery do you have or are you thinking of?

[Guest]

Thanks Mrhappy,

Some considerations that may be relevant (if you ask me);

1) Are you able to say the distance of cable run and the gauge of wire?
16 Gauge, a few 20-30"runs and 5 runs of approx 40-60'
2) How many motor units, how much current does each one take?
9 motors total - spec attached - not necessary they all run at once though...
3) What size battery do you have or are you thinking of?
Was thinking 1000 cranking amps

[mrhappy]

I can't find specific current use data about them from a quick look but I think you will probably be fine. Say if they consumed an amp at their top load (it probably also depends on weight/length of the attached blind) then you are going to drop .5v over 60' of copper cable approx. The blinds probably are going to be ok with that (considering the battery option they have) and they may have some internal regulation anyway. They might be slightly slower be worth looking to see if you can find the input voltage range in the specs anyway.

Your battery is probably fairly over sized really you could go smaller, I would certainly fuse all your respective cable runs, not sure I would want to run the risk of a short circuit.

[Guest]

Would you put individual fuses inline with EACH positive connection then instead of one fuse for all runs together?

[mrhappy]

I would myself if you only have one fuse then if it blows all your blinds are down, if you have separates then it will both eliminate this and point to where the problem is. The fuse is to protect the cable considering the devices apparent inbuilt protection.

[TomTom]

I've been running hundreds of feet of cat6 for cctv recently, so been dealing with some of these concerns.
At 16 gauge you'll barely see any drop. You could probably even double some of those lengths without any issues. I've been using 18 gauge essentially 2 of the individual cat6 wires together.

Not sure why you would want to use a deep cycle battery, unless you're concerned about power outage use.
You could use one of these, rated for 30A, and there is a larger one for 60A.
http://www.ebay.com/itm/Universal-12...p3tptA5EGZpcug

Since you need quite a few 12v lines, this would probable meet your needs. The other option is 12v cctv power supply, but they usually don't exceed 1A. The somfy power supplies are rated for 3a, so the ebay power supply would be better suited for this.
A fuse would could be used, but seeing that somfy doesn't use them in their power supplies(at least the ones I've seen) don't know if you need them. Seems the motor has the 2a over protection. If you need to put a fuse you could get a 2a auto fuse or and put that on every line of the power supply listed above.

[Guest]

Thanks TomTom and mrhappy,

It seems like a simple 12v supply works just fine if properly fused. The supply quoted to me did say it was fused.
I had considered an RV battery as that was RollerTrol advice, but obvious overkill too!
Seems like I'll save hundreds here. Advice much appreciated