Line capacity

[Westport Lights]

Hello all, like many others, I'm new this year and have stupid questions.

I got a 16PC and have 2 dedicated 20 amp GFI outlets.

I just recalculated my loads and realized that I need more than 8 amps on both sides for the "bursts" of all lights being on. I originally thought that I could control 2 minitrees per channel each with 3 strands of 150 minilights for a total of 450 lights per tree. It turns out that it would not be the best idea and is pushing/exceeding the limits.

So here's my question. What options do I have this late in the year? Order another 16PC and hope I get it in time? Do I need 2 more 20amp GFI circuits for the additional 16PC or can I plug each one into 1 20amp circuit? Any other options I'm not thinking of?

Talk about oversight, this is NOT good. I'll definetly be more prepared next year.

[MattCole]

I've found the spreadsheets created by Rick Williams VERY Helpful in caclulating power needs and controller loads. It makes it really simple to balance things out. It also higlights when you are out of range on amperage on a per channel basis or full controller basis.

Give it a try, I highly reccomend it!

http://www.quartzhillchristmas.com/12.html



Matt

[Donald Puryear]

Westport Lights wrote:

Hello all, like many others, I'm new this year and have stupid questions.

I got a 16PC and have 2 dedicated 20 amp GFI outlets.

I just recalculated my loads and realized that I need more than 8 amps on both sides for the "bursts" of all lights being on. I originally thought that I could control 2 minitrees per channel each with 3 strands of 150 minilights for a total of 450 lights per tree. It turns out that it would not be the best idea and is pushing/exceeding the limits.

So here's my question. What options do I have this late in the year? Order another 16PC and hope I get it in time? Do I need 2 more 20amp GFI circuits for the additional 16PC or can I plug each one into 1 20amp circuit? Any other options I'm not thinking of?

Talk about oversight, this is NOT good. I'll definetly be more prepared next year.

What heat sinks are you using? With the reg. heat sinks you can run at least 15v amps a side. Check the owners manual

[Westport Lights]

I really don't know what heatsink is on it. Whatever is shipped with the CTB16PC-COMPLETE. Should I get the better heatsinks or are they already on them??

A little more info . . . Each minitree is pulling 1.5amps, there are 16 of them, I originally was going to put 2 trees on each channel, but it looks like when they are "all on" for a few seconds, that's pushing the limits? They are never on statically, maybe 10 seconds at the most.

I just ordered another CTB16PC but we'll see when it actually arrives. I think that if I split the channels evenly across all 4 legs of both controllers and limit the additional areas that I set up I'll be ok.

[Donald Puryear]

Unit ships with the regular heat sinks. Each channel 8 amps, each side 15amps ( if feed from two circuits) One unit is all you need (1.5 X 16=24 amps)

[Westport Lights]

16 trees was only 1/2 of the display. We have our house to light too. You did confirm my main concern though. I need 2 controllers. 1 for house and 1 for the 16 minitrees. Thanks!

[Cajun Cheesehead]

I'm totally new at this but maybe this will work (someone correct me if I'm wrong). For the times when you may push the limits in your sequence, maybe try dropping the intensity of everything a little bit.

It may lessen the effect, but you can still salvage what you have done so far until you get a new board.

[tsrail]

Cajun Cheesehead wrote:

I'm totally new at this but maybe this will work (someone correct me if I'm wrong). For the times when you may push the limits in your sequence, maybe try dropping the intensity of everything a little bit.

It may lessen the effect, but you can still salvage what you have done so far until you get a new board.

I saw a post recently here or on PC where someone did some testing with a KillOWatt (or similar ammeter).

The results were interesting, as when you apply 50% power to various types of lights, you still pulled 80-90% of the amps. Even at 10-15% power, you were around 50% of the amps.

Again - I read this on a post (haven't tried it myself yet), but this experiment could be easily duplicated with a KillOWatt meter, to see if running your lights at 50% gets you the amp level you need.

Good Luck!

[Tim Fischer]

Westport Lights wrote:

I just recalculated my loads and realized that I need more than 8 amps on both sides for the "bursts"

Just to be clear, the limit is 8A per channel, not per side. The limit per side is either 15A or 20A, depending on your fuses and wiring.

-Tim

[MattCole]

To clarify Tim's post a little bit more. It's 15 amps per side only if you are powering from 2 separately circuit breakered 15 amp outlets and are not jumpering power between the two sides of the board.

Matt