Slightly bemuddled

[Daemon]

Can someone point me to the wiki part or a suitable post so I can read up on the different ratings etc of my lights.

I am in NZ and I have got 3 toroidal transformers rated at roughly 230 volt - 24 volt(after voltage drop) Each one is 400va or slightly less and will drive 4 ssr boards(I hope) for a total of 48 channels.
My other 16 channels will be from ssr power outlet boards modified to add ssr's.

My design will not be plug and play because I have added the tranformers.

The power board design is simple because I can simply plug in the existing adapters and away they go.

The part I am struggling a little with is the transformer ssr boards because all of my lighting has slightly different ratings. Some are 24va, some 20 others 22.
The there is the led ones with are 4.8watts(va roughly). I will not be attaching outlets to my ssrs because they are hideously expensive here so I was going to hard wire the lighting to the ssr's.
What alterations do I need to make to the ssr for a differently rated light set?

If that doesn't make sense my leds for instance, 1 string of leds is a series of 4 led bells and I was going to chop them and make them 4 channels so I can operate them individually. How would I alter the ssr so they don't blow up?
Would I need to build a special ssr or do I wire a resistor between the ssr and the lighting?

Hope that makes sense as I am about to start a night shift and I am off to bed.

Thanks all
Steve

[prof]

Assuming you are using the OZSSR coop board.

For the 24VAC setup.
The OZSSR board has (due to track size), about a 2 Amp limit per individual channel or 48VA per channel @ 24VAC. The board is also meant to have a maximum of a 5A fuse fitted which limits the total combined load for the board to only 120VA @ 24VAC.

So you just need to juggle the loads around so that you do not exceed the channel load of the SSR or the total board load or the transformer load.

The incandescent bulbs are OK to run directly from the SSR but you will need to provide a bit more info on the LEDs as they work on DC. Are the LEDS of the type that has the 24VAC plug pack and the inbuilt controller that you want to cut off to run them from the SSR ?

Craig.

[toodle_pipsky]

I ran roughly 40 channels off 1 300va toroidal transformer for 2008. The total va "rating" for all the lights running off it was 322.8va - pushing the limit, but I ran out of time and money to get another transformer. What I did do was load the info about my lights into the watt meter in Vixen and found that I didn't have all my lights on at any given time and that even at it's busiest, I wasn't pushing the limit of the transformer.

It probably sounds ultra tedious and a bit geeky - but ultimately safer - get yourself a spreadsheet going, it definitely helped me to wrap my head around power requirements.

I listed CHANEL NUMBER, DESCRIPTION (matched what I'd called it in Vixen), VA and BOARD. I've attached mine to give you a bit of an example, but I have seen much more organised layouts than this! But at least you can group channels/boards together and see what power it draws.

Hope this helps you get you on your way!

(And have a good sleep for night shift! :) )

[TimW]

Hi Steve


Can someone point me to the wiki part or a suitable post so I can read up on the different ratings etc of my lights.

I am in NZ and I have got 3 toroidal transformers rated at roughly 230 volt - 24 volt(after voltage drop) Each one is 400va or slightly less and will drive 4 ssr boards(I hope) for a total of 48 channels.




The part I am struggling a little with is the transformer ssr boards because all of my lighting has slightly different ratings. Some are 24va, some 20 others 22.


Lets look at this a slightly different way... the important thing about your torroidals is the 400VA rating... it means (roughly) that they are rated for maximum 400W of lights ... which is the same thing as saying that at 24V they can supply a maximum of 400/24= 16.6A

Similarly your 20VA string is rated to draw a maximum of 24/20=1.2A
So in theory you could connect 13 of these to a single transformer (that's why we use torroidal transformers.. saves on the number of plugpacks!)

Just make sure the total VA of the transformer is greater than the sum of the VA load you want it to drive.

What's important is how many lights you connect to each transformer (not the number of SSRS or channels you connect). Of course there is still a limit on how much current you can put through 1 SSR channel - but its good for a 20VA string comfortably.



My other 16 channels will be from ssr power outlet boards modified to add ssr's.

The power board design is simple because I can simply plug in the existing adapters and away they go.



Same here. One point though... are you using the power outlet boards to drive plugpacks? Its much better to switch the lights on the 24v side of the plugpack as opposed to the mains side (like you are doing with the torroidal). The little black plugpacks don't like all that switching on and off. It makes them hot (and sometimes a little bothered even...)



My design will not be plug and play because I have added the tranformers.


welcome to DIYC! :)




The there is the led ones with are 4.8watts(va roughly). I will not be attaching outlets to my ssrs because they are hideously expensive here so I was going to hard wire the lighting to the ssr's.
What alterations do I need to make to the ssr for a differently rated light set?

If that doesn't make sense my leds for instance, 1 string of leds is a series of 4 led bells and I was going to chop them and make them 4 channels so I can operate them individually. How would I alter the ssr so they don't blow up?
Would I need to build a special ssr or do I wire a resistor between the ssr and the lighting?



That depends on how the light set is wired and powered.
There are several possible ways they could have done it - we need to safely figure it out. Can you post some pictures of the set? - then the people here will ask some questions and we can go from there.

A couple of key things about the SSRs - there are 2 types depending on whether we're switching AC or DC (Leds are DC or AC rectified...). Also there is a resistor on the AC SSR (SSROZ) that is usually changed depending on the voltage you are switching (see wiki or sticky ssr posts for info on this).You may need to consider different resistors depending on whether you're switching 240 or 24 volts for example.


Tim

[jgrei1]

the important thing about your torroidals is the 400VA rating... it means (roughly) that they are rated for maximum 400W of lights ...


that is very true tim, i just felt i had to add this though. while saying this, you must also remember that VA is i measure of apparent power, not actual usable power.

using purely resistive loads the va rating is pretty much the same as watts... but if its an inductive or capacitive load it would probably be better to derate the transformer a little.

[Daemon]

Assuming you are using the OZSSR coop board.
Are the LEDS of the type that has the 24VAC plug pack and the inbuilt controller that you want to cut off to run them from the SSR ?

Craig.
Hi Prof. Thanks for the reply. The leds are of the type that have a 24 vac plug pack. To put this another way more simply, how can I add these to my display using the toroidal setup I have?
Do you need some photos? I think they are Australian products anyway, holographic bells with leds from Mirabella.

[Daemon]

What I did do was load the info about my lights into the watt meter in Vixen and found that I didn't have all my lights on at any given time and that even at it's busiest, I wasn't pushing the limit of the transformer.

Thanks Toodle Pipsky. I hadn't got that far but thats a great idea and a useful tool I will definitely be utilizing when I get there.
40 channels is a lot of lights for one transformer seeing as I am using slightly larger rating transformers and using 3 of them to drive 64 channels.
That means when I add new controllers later(and lets face it, its definitely going to happen!) that I probably wont need any more trannies.
Thanks

[Daemon]

Same here. One point though... are you using the power outlet boards to drive plugpacks?

I was planning on using the plug packs but having read further now I see it is advisable. There is a lot of great info in the wiki but when it comes to diagrams and specifics of your own setup and style it is a bit hard to find the relevant info.


Can you post some pictures of the set? - then the people here will ask some questions and we can go from there.

See my reply to Prof. I think they are fairly common place but I can post a photo if needed.

Great answer. Thanks for taking the time.